never buying another Johnson

CharlestonFishing.Com
https://www.charlestonfishing.com/forums/Topic/Posts/182912?pagenum=1
07/10/20 17:12

Topic


PalmerScott
never buying another Johnson
10/14/19 3:07


Stupid motor only lasted 25 yrs. /sarc

Is piston supposed to look like this?

Appears to have eaten a ring. Inside of head looks like tip of piston.

Old girl ran like a top for a long time. Never failed to get me home. Not one time.

Guess it's time to start researching repower options.


---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25

 

Replies ...


boatpoor
10/15/19 0:39


Beats having a black motor! Love my E tec, 8 years now not a birp!
mdaddy
10/15/19 17:34


Little hone job / used piston / set of rings and you in business...(sarc)

Find a engine made today that runs for 25 years without costing you an arm and a leg.


The ENTER-NET Fisherman
PalmerScott
10/16/19 15:34


Little hone job / used piston / set of rings and you in business...(sarc)

Find a engine made today that runs for 25 years without costing you an arm and a leg.


The ENTER-NET FishermanOriginally posted by mdaddy


You joke. But, I enjoy playing with these things. HenryO hull will definitely get new power. Love that hull.

The old Johnson 2moker may get played with just for fun. Never tried to do a piston and rings.

Questions about a replacement piston. I see Sierra piston kits for about $100 (piston, rings, wrist pin, and clips). Maybe could find a used donor. Is it possible to remove carbs and reed valve assembly and get at the front of the connecting rod bearing? If so, I may try a hone and new piston. Cylinder is scored some. But , I've broken down motors that looked nearly as bad and went back together and ran a long time. Held 50 psi like she was, if a little work got her 90 or better..... Would never sell without disclosing full history. Shoot, history is literally on the internet

And, I have a 14' Bentz with the same transom bolt pattern. And, I've seen several 14s carrying old Merc and OMC 90s. Could be fun.


Hey, hold my beer.... Watch this.....bigsmile

Will have to see if I can break any time free to play.


---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
mdaddy
10/17/19 3:09


Little hone job / used piston / set of rings and you in business...(sarc)

Find a engine made today that runs for 25 years without costing you an arm and a leg.


The ENTER-NET FishermanOriginally posted by mdaddy


You joke. But, I enjoy playing with these things. HenryO hull will definitely get new power. Love that hull.

The old Johnson 2moker may get played with just for fun. Never tried to do a piston and rings.

Questions about a replacement piston. I see Sierra piston kits for about $100 (piston, rings, wrist pin, and clips). Maybe could find a used donor. Is it possible to remove carbs and reed valve assembly and get at the front of the connecting rod bearing? If so, I may try a hone and new piston. Cylinder is scored some. But , I've broken down motors that looked nearly as bad and went back together and ran a long time. Held 50 psi like she was, if a little work got her 90 or better..... Would never sell without disclosing full history. Shoot, history is literally on the internet

And, I have a 14' Bentz with the same transom bolt pattern. And, I've seen several 14s carrying old Merc and OMC 90s. Could be fun.


Hey, hold my beer.... Watch this.....bigsmile

Will have to see if I can break any time free to play.


---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25Originally posted by PalmerScott


I enjoy your posts.

I believe you can separate the crankcase from the block( if you are a wrench freak), but , it could/would be a waste of time. I've never done it...seen it done ...and there's this:
https://forums.iboats.com/forum/engine-repair-and-maintenance/mercury-mariner-outboards/341319-replacing-johnson-outboard-piston


The problem is the more 25 year old bolts you remove...the more chance of breaking them. Depends on what you want when you get done and what the rest of the motor is like. I had an 88...that was a running junk pile...and I sold it... ran forever. I got into boating by buying other peoples junked motors and trying to fix them.

2 strokes may not be efficient...but...they very seldom quit on you. Not much that can go wrong...KISS principle. Personally, I get all the goody out of something before it goes to scrap.

I'll be watching for your progress. Post some pics and let us know what you do.




The ENTER-NET Fisherman
contender1
10/17/19 20:47


“Beats having a black motor”. “Got 8-years on my etec”. Eight whole years? I got underwear older than that! 23-years on my 30 hp tiller Merc with no issues. Poor mouthing abounds but my Seasoned personal experience tells me otherwise.
boatpoor
10/19/19 23:39


If I could post pictures I would post one of the 7 v6 Mercs that have holes in the block hanging on stands behind my barn. Altho I have a running 2.4 200 84 model that still runs great
40inchreds
10/20/19 15:20


Go to any old country area or mountain area where money is an issue every motor around is a old smoker. I had a Johnson 70 that was bored to a 90 by a airplane mechanic and his buddy who was a machinest. Two strokes are great.
PalmerScott
10/20/19 20:42


Well.... She's done.
Carbs came off easily as they got cleaned every few years. Reed assembly came off easily = surprise! Reeds looked great. Outer crankcase bolts came easily = more surprised. 4 of the 6 Allen head crankcase bolts came out clean = (beginning to hope I have something to play with)...... Then, the two lower Allen head bolts seized hard. Could pull the power head and put some heat on them.... But, that's more than I'm willing to put in to her. Parting her out. Everything worked except that the new cylinder. Anyone need parts for a mid 90s OMC/Bombardier?


---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
demasb
10/21/19 0:00


Sorry to hear the motor has reached the end of it’s useful life for you. What horsepower is it?
PalmerScott
10/21/19 0:49


1995 Johnson 88spl. No VRO. Does have trim/tilt. The 88 special is literally a 90 with slightly lower amperage output (6 amps instead of 9, I think).


---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
TheMechanic
10/21/19 12:13


i sure wish that was a 1995 ocean runner. i'd buy the whole setup. im looking for a power pack


_____________________________________________________
Proline 201WA
Aloha 24ft pontoon (LooneyToon)
Old Town stern with 7.5 johnson
PalmerScott
10/30/19 14:26


Here's a mystery.

That motor on that hull has always done 30-31 mph WOT. I always thought a 90hp should push her better than that but, she ran smoothly, idled nicely, and generally behaved herself if she had clean carbs. Slightly disappointing fuel economy but she's a 25yr old 2-smoker.

Here's the mystery. The last trip, after fishing a spot, 'had a little difficulty getting her to start. She'd spin and fire, stumble, and die. She did it maybe 10 times. Then, got enough start-up lever in her and she fired up and ran. Figuring low speed jets were dirty, I ran her WOT back to the trailer. 31mph.

Second part, on the hose in the driveway, I did a little tidying up of the timing linkage and she went back to purring at idle. I figured since she was warmed up, I do a quick compression test and that was my first evidence of a bad cylinder.

Note that the intake side of the piston face has more carbon build up and there is carbon in and on the dents left by the piece of ring bouncing around in the cylinder. Same is true on the under side of the head.

Question: have I been running on a very weak cylinder for a long time? Curiosity is getting the better of me. I think I'm going to pull the power head and see if I can't get those last two crank case bolts to free up. If I can, will get a piston kit and put her back together. I have no expectation that she'll hold together for very long. But, I'm getting ready to have to buy a new motor. Have been thinking a 115 or larger. But, if a 90 4 stroke will push her near 40mph, I'll save some transom weight and go back with another 90? Decisions... decisions.....





---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
mdaddy
10/30/19 17:18


Here's a mystery.

That motor on that hull has always done 30-31 mph WOT. I always thought a 90hp should push her better than that but, she ran smoothly, idled nicely, and generally behaved herself if she had clean carbs. Slightly disappointing fuel economy but she's a 25yr old 2-smoker.

Here's the mystery. The last trip, after fishing a spot, 'had a little difficulty getting her to start. She'd spin and fire, stumble, and die. She did it maybe 10 times. Then, got enough start-up lever in her and she fired up and ran. Figuring low speed jets were dirty, I ran her WOT back to the trailer. 31mph.

Second part, on the hose in the driveway, I did a little tidying up of the timing linkage and she went back to purring at idle. I figured since she was warmed up, I do a quick compression test and that was my first evidence of a bad cylinder.

Note that the intake side of the piston face has more carbon build up and there is carbon in and on the dents left by the piece of ring bouncing around in the cylinder. Same is true on the under side of the head.

Question: have I been running on a very weak cylinder for a long time? Curiosity is getting the better of me. I think I'm going to pull the power head and see if I can't get those last two crank case bolts to free up. If I can, will get a piston kit and put her back together. I have no expectation that she'll hold together for very long. But, I'm getting ready to have to buy a new motor. Have been thinking a 115 or larger. But, if a 90 4 stroke will push her near 40mph, I'll save some transom weight and go back with another 90? Decisions... decisions.....





---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25Originally posted by PalmerScott




If the block and crank are good...
http://smellofdeath.com/lloydy/piston_diag_guide.htm



The ENTER-NET Fisherman
mdaddy
10/31/19 4:10


I got enough stool to work on around here, but, I gots to know why that piston ate the ring.

The cylinder got hot due to the ring failure or some other cause?

If you get apart, I'd like to know if the locating pin failed...or just old rings.

Show me a four stroke that will run with damage like that.




The ENTER-NET Fisherman
PalmerScott
11/22/19 15:52


Well, here's the problem child. I am absolutely amazed this motor was running reasonably well/smoothly with this in one of the holes. I guess 50 psi compression is more than zero. But, hard to believe.

Obviously, spit out the entire top ring and took a few chunks of the piston with it. Can not believe the entire ring made in into the combustion chamber and got spit out. Didn't get back down into the crank case = would think that would have destroyed everything quickly.

I broke three bolts getting her apart. If I can either get those out or helli-coil them I'll order a piston kit, hone the cylinder a little, and throw all this back together. See if she lasts longer than 5 minutes.






---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25


---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25


---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
boatpoor
11/22/19 22:41


that's unreal, thanks for the pictures! Good luck on the rebuild hope it runs another 24 years!
mdaddy
11/23/19 18:04


You mention that you thought the boat/motor was slow but OK:

"That motor on that hull has always done 30-31 mph WOT. I always thought a 90hp should push her better than that but, she ran smoothly, idled nicely, and generally behaved herself if she had clean carbs.

I wonder if it was propped right? Just a thought.

https://forums.iboats.com/forum/engine-repair-and-maintenance/johnson-evinrude-outboards/101539-96-johnson-115-piston-head-damage-pics

The picture of the piston that you have appears that the ring locating pin broke loose. The lugging may explain the heat build up. Just a thought. Good luck with the rebuild. Beeswax and heat are our friends.


The ENTER-NET Fisherman
PalmerScott
11/25/19 19:04


mdaddy,

I've forgotten the numbers, but, I ran a 15 3/4" x 17" prop on her for a long time and she was right below the bottom of the prescribed range for WOT RPMs. About a year ago, I dropped to a 16" pitch prop and it made almost no difference. RPMs went up as expected, but, speed stayed just about the same. Fuel burn stayed about the same. So, I think that means that even if she was a little below the prescribed WOT range, she was doing OK with the 17" pitch.

Regarding the ring locator pin, it is still there and in pretty good shape. It is just around the side of the piston in that pic where you cannot see it. The amount of carbon built up in that top ring lane makes me think this old girl spit that ring out a long time ago. Much of that lane is almost completely full. And, it is hard as a rock. Its been in there baking in place for a while.

Had three bolts that I'd twisted the heads of off and could not get out of the block. After heating gently and shooting with PB Blaster (don't know if the stuff works or not - but, gave it a try) and leaving it for two days. Then, came back, more heat, vise grips as tight as I could get them and got two of the studs out. The third would not budge and I was torquing on it so hard I was a little afraid of ripping a chunk of aluminum out. So, cut it off about 1/8" tall. Filed it flat. Put a sharp felt tip dot in what I thought was the center. Center punched the dot several times to give good dimple and started drilling with a very small drill bit. Stepped up right through the bit set until I started to see the hint of threads in the wall of the hole. Ran a tap through the hole and it cleaned out nicely. I've tried to do that trick dozens of times over the years. This is the first time I did not end up having to over drill and heli-coil or re-tap it. Very Very lucky.

So, ordering a piston kit and a variety of gaskets. When the parts arrive, I'll put her back together.

Once I get the piston in, I'll hook a drill motor up to the top of the fly wheel and spin her slowly, feeding her 2-cycle oil in the cylinders for a few minutes to make sure nothing catches an edge with the new rings. Then, maybe speed up and spin it with the drill for 10 minutes or so.... feeding oil the entire time. If everything is smooth and stays smooth, put her back together. I think if she runs 2 minutes, she may run a long time. She may not run 2 minutes. We'll see :-)

Should start a pool on how long she runs.
I'll buy the winner a beer. (Or, maybe the winner should buy me a beer. ;-) )



---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
40inchreds
11/25/19 21:45


If you got skills a rebuild should last as long as the original or longer. 2 smokes are built to be rebuilt. I'm sure some other things will take a dive since they are 25 years old
mdaddy
11/26/19 3:59


There's an art to working on junk. I like your dedication and tenacity. They be in short supply in most cases.

Now, what is this???:



Bolts break...no mater what. Feels good when you drill one out right. I don't know which works better about loosening agents. I like watching the wax get sucked in. PB blaster seems to work...wax isn't as flammable...so there's that.

The picture looks like a locating pin stuck to the piston... Or cracked up through. Either way, find a good machine shop to check the block and crank since it's apart.(Nice to have other eyes depending on price and you having micrometers)

Considering your drive to fix something, I'm in the pool !!!!!!... that with that motor done right... might outrun you.

Enjoy your work.




The ENTER-NET Fisherman
PalmerScott
11/27/19 15:38


There's an art to working on junk. I like your dedication and tenacity. They be in short supply in most cases.

Now, what is this???:




Not sure what the round shape is. The ring locator pin is intact. Only guess, is a purely random shape produced while the ring was being spit out. It appears to be made of the same material as the rest of the piston body. Here's a pic of the intact ring locator pin.




The picture looks like a locating pin stuck to the piston... Or cracked up through. Either way, find a good machine shop to check the block and crank since it's apart.(Nice to have other eyes depending on price and you having micrometers)




The ENTER-NET FishermanOriginally posted by mdaddy


I'm livin on the edge. No micrometers here. Everything else on this old girl is 25 years old and she just doesn't warrant any significant investment. I'm gonna spend about $180 on parts and throw her back together. See what happens.

I'm going to be optimistic as say she runs another couple of years. I'll try to remember to video her first start. Could be comical.


---------------------------



---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
mdaddy
12/05/19 17:40


Good for you. That motor laughs at micrometers.

Much simpler motor that did what it was posed to do...start and run...and doesn't need 20 sensors to do it.


The ENTER-NET Fisherman
PalmerScott
12/05/19 21:31


Don't know when I'll get to it... may be this weekend. But, ...... parts!




---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
PalmerScott
12/08/19 3:14


Progress.



Piston to con rod small end done. Needle bearings are a pita. You have to nest the bearings in the end of the con rod. Then, slide wrist pin into piston and through bearings with out having them collapse....which they do. Manual says buy this tool which is just a little plug the width of con rod that sits inside bearings until the wrist pin pushes through. Had a tapered candle. Mic'd the wrist pin and cut a 1/2" length of candle. Perfect. Easy on aluminum piston and held bearings in place.

Install rings. Slather with 2 cycle oil.
Slide into cylinder and mate to crank.

Lightly tightened con rod end cap and spun crank several revolutions. Everything was smooth.

In the am, torque con rod end cap. Close case. Reinstall all the 12million things I removed.


---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
chris V
12/10/19 14:18


people rarely understand the NEED to do a carbon treatment on their motor.
Based on the pictures, if I were betting, I would bet that you got carbon build up behind the rings, ring sticks out just bit farther than it should, and catches the edge of the port on the way down. The broken piece of ring ends up banging around on top of the piston until it gets spit out the exhaust port.
Seen it happen over and over again.
Morale of the story...
the inside needs to be clean as well as the outside

PS
if you ever do another build like this, you can order caged needle bearings for most motors, and they are only a few dollars more than loose bearings, and vaseline does a really good job of holding the loose bearing in place while doing your assembly.


www.teamcharlestonmarine.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING
mdaddy
12/10/19 23:14


Get it man. Those needle bearings will make you swear.

I rebuilt a Merc 125 that had those as well as 6 different ring compressors. My girlfriend at the time was trying to help me put the assembled crank back in the block while taking off each ring compressor...and told me where I could put the whole motor. She never did get a boat ride.

" Mic'd the wrist pin and cut a 1/2" length of candle. Perfect." The only thing mic'd was a candle...classic. My long lost twin.
Won't be long now.


The ENTER-NET Fisherman


The ENTER-NET Fisherman
PalmerScott
12/11/19 15:06


Quick clarification on two points.

First, I hoped that it might be possible to split the crankcase with out removing the power head from the exhaust adapter and it was suggested that it might be possible. It may be possible on other motors, but, on a 1995 88spl (or 90, or 112, or 115), there are two bolts going up through the bottom crank case head assembly (bottom end bearing cover) through the cover and into a ring that goes around the crank shaft. You cannot open the crankcase without removing those two bolts. No way to get to those to bolts without removing the block from the exhaust adapter.


Second, I cannot lie. I did not 'mic' the wrist pin. I used a vernier caliper which I like because it makes me look like a Wizard when people see me use it. Invariably, "how do you read that"? (Knew how to use a slide rule for about a month, then never picked one up again. Those guys are Wizards.)



---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
Fred67
12/11/19 18:28


Slide rule?! They quit making those in the late 70’s. smile. Talk about old school. I wonder how many are out there that could still read one?
chris V
12/11/19 21:28


slide rule...
okay guys im 52 and my dad used one when i was kid
and he is 87 now
I am sure he still has one somewhere.
I will stick with my cell phone


www.teamcharlestonmarine.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING


www.teamcharlestonmarine.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING
gail wins
12/11/19 22:14


got one i used in tech school and work calculating electrical loads and the such ;( it still works but i don't anymore )


George McDonald
US Navy Seabees,Retired,
MAD, Charleston Chapter
[http://www.militaryappreciationday.org


When you see "Old Glory" waving in the breeze, know that it is the dying breaths of our fallen hero's that makes it wave.
author unknown
Off the chain
12/11/19 22:49


Slide rule?
Is that like a part for a sundial or something?


I am fragile.
Not like a flower.
But like a bomb.
gail wins
12/12/19 1:58


Yeppers or sumthin !!!bigsmilebigsmilethumbsUp


George McDonald
US Navy Seabees,Retired,
MAD, Charleston Chapter
[http://www.militaryappreciationday.org


When you see "Old Glory" waving in the breeze, know that it is the dying breaths of our fallen hero's that makes it wave.
author unknown
boatpoor
12/12/19 3:25


I've still got one of mine in my desk i used before I got a calculater in 1965. It would add, subtract, multiply, and divide and cost only $1,200. It was 12" square and weighed 2 lbs
PalmerScott
12/16/19 1:18


Promising.....



---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
mdaddy
12/16/19 1:55


Promising.....



---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25Originally posted by PalmerScott


You got a Gorilla doing your manicure?

You kinda hard on that hand.

Nice job...and quick too. I believe I hear it running. That Henry O might run a little faster with all 4 cylinders.


The ENTER-NET Fisherman
gail wins
12/16/19 2:05


The hands of a working man ; no time for manicures there for snowflakes anyhow....wink
wink


George McDonald
US Navy Seabees,Retired,
MAD, Charleston Chapter
[http://www.militaryappreciationday.org


When you see "Old Glory" waving in the breeze, know that it is the dying breaths of our fallen hero's that makes it wave.
author unknown
PalmerScott
12/16/19 15:11


Late yesterday afternoon, hooked her up to the hose. Because I'd slathered everything inside her (including the cylinders) with 2-cycle oil, she had to spin ten or twelve rotations before she fired, and the first fire was a huge backfire. Scared every dog within a mile and set off a huge barking. My German Shepherd came out of the garage and looked at me like W-T-H Was THAT!? Next turn of the key and she was running. Took her a little while to work through all the extra 2-cycle oil in the crankcase (and I'm running her on 25:1 for break in) so there was some stumbling and coughing. But, a light touch of throttle would smooth her back out. Watched temps of heads as she warmed up. Bottom pairs of heads sat at about 145 degrees and the tops just a little warmer closer to just under 150. Compression check after running about 30-40 minutes showed about 130 psi on the new piston.

I'm a glutton for punishment. Getting that hole up to 130 psi makes me immediately think, I could buy 3 sets of rings, pull the other pistons, hone the holes, and slap it all back together again. But, I think I'll resist that dark thought, put her in the water and see if she make it through a gentle break in. I think I can do a little trolling for trout while we let those new rings wear in.


Here's another surprising thing. I kinda' regularly point a laser thermometer at my heads to make sure they are cooling. Been doing it for years. Before I tore her open, I was getting external head temps in the 140s. 'About where they should be, I think. When I pulled the stbd water jacket cover off it looked like this. The channels on the other side of that gasket were just as bad. Channels in the block were generally clear and took very little light wire brushing to clean up. Pulled the port cover off and cleaned that side also. Can't believe she was cooling given that much salt buildup .



---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
mdaddy
12/16/19 15:40


Good for you my man. Thanks for sharing your rebuild with us.


The ENTER-NET Fisherman
Off the chain
12/16/19 17:02


It's definitely nice to be able to fix your own stuff. It's a good feeling when you hit that key and she comes to life.



I am fragile.
Not like a flower.
But like a bomb.
chris V
12/16/19 17:05


MAKE SURE AND VARY THE RPMS BY 200-300 EVERY 10 MINUTES DURING THE BREAK IN AT LOW RPMS FOR THE FIRST HOUR.
2ND HOUR SHOULD BE 1500-2000 RPMS, VARIED EVERY 10 MINUTES.
3RD HOUR TO 10TH HOUR, PLANING SPEED, WITH BURSTS OF WIDE OPEN THROTTLE FOR NO MORE THAN A MINUTE OR 2.
I KNOW ITS HARD, BUT MAKE SURE NOT TO NEGLECT THE WOT BURSTS. IT NEEDS THE LOAD TO PROPERLY BREAK IN.


www.teamcharlestonmarine.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING
PalmerScott
12/16/19 18:00


Thanks for the break in recipe, Chris. I knew I needed to follow a routine, but, did not know the recipe.

Re: the manicure, that's the best I can do with a wire brush on a drill motor and pocket knife.


---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
PalmerScott
12/29/19 19:23


After a couple of hours of running around below 2000rpms and varying speed, pushed her slowly up on a plane. After a few more minutes, went to WOT. Think she had a fouled plug and she topped out right at 30mph. Throttled back to about 3500 rpm for a minute or two and she picked up the missing cylinder. With fire in all 4 holes, WOT was 37mph at nearly 5000rpms. 7mph faster than she's ever seen. Hops out of the hole like she's been goosed. I am convinced she's been dragging a very weak cylinder for a long time.

So, I think I'll pull the 16" prop and put the old 17" back on and see if she'll push it. If she can make a little more speed with the 17" pitch, new power will likely be a new 90, rather than a 115 or bigger.


---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25


---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
StumpNocker
12/30/19 13:08


Excellent results. Well done!thumbsUp


Fishing Nerd

"No bar, no pinball machines, no bowling alleys, just pool... nothing else."

...well, some fishing too!
boatpoor
12/30/19 21:56


Why not try for another 28 years out of it! Glad to see you got it running right.
mdaddy
12/31/19 16:43


I can hear you yelling repeatedly...

WHO'S THE MAN!!!!!!!!!!!!!

All the way down here.

I'm smiling with you. Thanks for sharing.

Forget the 4 stroke...the fuel efficiency isn't worth the maintenance.


The ENTER-NET Fisherman
chris V
01/03/20 19:01


if you are only seeing 5000rpms WOT with the 16 pitch prop, DO NOT CHANGE TO A 17
you would actually want to see 5500 rpms with a light load.
if anything you need to drop to a 15 pitch.
remember, the bigger the prop the more load you are putting on the motor.


www.teamcharlestonmarine.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING
PalmerScott
01/06/20 15:48


if you are only seeing 5000rpms WOT with the 16 pitch prop, DO NOT CHANGE TO A 17
you would actually want to see 5500 rpms with a light load.
if anything you need to drop to a 15 pitch.
remember, the bigger the prop the more load you are putting on the motor.


www.teamcharlestonmarine.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLINGOriginally posted by chris V


Chris, spot on.
Figured I'd check to see if the laws of physics were still in effect.
That are.
With the 17" pitch, slower, but OK, hole shot.
Lost maybe 1 or 2 mph. Hard to tell with Saturday's wind and current. Average of several runs in both directions - still hard to tell if the difference was real.
Max WOT rpm dropped to about 4650 - to low.

It is interesting how the slip number behaves. I get better speed at about 3600 rpms with the smaller prop. I didn't expect that. Seems given an RPM, and foot gear ratio, and a prop pitch, you 'd be generating more thrust with the 17" than the 16". But, somehow, the 16" pushes her faster at that RPM? I'm missing something. Or, my data is bad. I see how fuel consumption should change. But, why is the lower pitch faster? Must be more to the different prop shapes than I was thinking? Diameters are different, also. Weird.

So, the smaller prop goes back on.

Found the timing retarded by about 4 degrees this weekend. Adjusted it. So, I'm hoping I'll get a little bit more at WOT with the smaller prop getting it a little further above 4800.


Anyone know of any Johnson 115 parts from that era?
Might be fun to put the baby-butt exhaust cover and 115 carbs on her and see what she does.
Not really interested in spending money. But, I just had the exhaust cover and carbs off. Would be an easy swap if I happened upon some clean cheap parts.



---------------------------
17' Henry O Hornet w/ Johnson 88 spl
26' Palmer Scott project hull
14' Bentz-Craft w/ Yamaha 25
mdaddy
01/06/20 17:59


Have you ever weighed the Henry O? What year is the hull? Something isn't right.

The higher the pitch...greater distance traveled.

"One inch in diameter absorbs the torque of two to three inches of pitch.

Both pitch and diameter absorb the torque generated by the engine. Diameter is, by far, the most important factor.


Thus, the ratio of 2 to 3 inches of pitch equals1 inch in diameter is a fair guide.

Since top engine RPM is constant, increasing pitch means more speed. Then, why aren't all propellers as small in diameter as possible, with gigantic pitches?"

The answer is simply that when the pitch gets too large, the angle of attack of the propeller blades to the onrushing water becomes too steep and they stall. "

Here is some more on slip:
THRUST AND SLIP

High-speed runabouts and fast cruisers require relatively low thrust and therefore operate at low slip whereas tugs and other heavy vessels require high thrust and therefore operate most efficiently at high slip.

If the boat were tied to a dock, the propeller would not advance at all but would generate maximum thrust because full engine power would go into accelerating water astern. This would be called operation at 100% slip.

Slip must not be confused with efficiency that is a measure of the percentage of engine power converted to thrust by the propeller.

We have seen that we must have slip in order to generate thrust and the amount of slip will be proportional to the amount of thrust required by the boat.

Since force (thrust) is equal to mass times acceleration, it would seem that we might get the same force whether we gave a large acceleration to a small mass of water (small propeller turning fast), or a small acceleration to a large mass of water (large propeller turning slowly).

In practice, however, there are other factors such as the relation of the propeller pitch to its diameter and the energy losses due to friction between the accelerated water and the surrounding water that make a proper relation between boat speed and propeller shaft speed essential to an efficient installation. "
The notes are from when I was trying to prop my cat...for what's worth.

BTW, since you trying to trick that "old" motor out...I take back my bet on how long she'll run. Old and slow is how I roll.


The ENTER-NET Fisherman
chris V
01/06/20 19:37


slip can make a huge difference, and slip changes at different speeds with different prop diameter and blade shape.
if you do find a donor motor, and want to see a huge improvement in throttle response and mid range acceleration, put in a set of composite reeds

based on the comment from mdaddy, there are a few flaws...
max rpm is not constant, so changing pitch definitely changes max rpm.


www.teamcharlestonmarine.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING
mdaddy
01/07/20 4:24


slip can make a huge difference, and slip changes at different speeds with different prop diameter and blade shape.
if you do find a donor motor, and want to see a huge improvement in throttle response and mid range acceleration, put in a set of composite reeds

based on the comment from mdaddy, there are a few flaws...
max rpm is not constant, so changing pitch definitely changes max rpm.


www.teamcharlestonmarine.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLINGOriginally posted by chris V


Propping is done by WOT as you know. Max rpm is constant...if all 4 cylinders are working correctly. As the pitch is increased, distance traveled and rpm increase...till the prop can no longer bite. It makes no sense that his rpm dropped going up in pitch only. IMHO.


The ENTER-NET Fisherman
chris V
01/07/20 15:02


thats the flaw in your argument...
max RPM is not constant.
if you had unlimited horsepower, max RPM would be limited only by the rev limiter.
You do not have unlimited horsepower.
changing the prop pitch changes the load on the engine.

think of it like riding a 10 speed bike up a slight hill
you are the engine.
you have a limited amount of power.
if you try to ride that bike in 10th gear, your RPMs are going to be much slower than if you change to 1st gear.
same engine, same bike, same hill, changing the gear( the prop pitch) will change the speed at which you can pedal (prop rpms)


www.teamcharlestonmarine.com
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING
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