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1968 TRL-10R bogs down

J

Jay1234

Regular Contributor
Hey all,
I have a 1968 Johnson 55hp TRL-10R that we have been running for the last 3 years. Pushes a 15' tri hull. Ran great all year last year. Probably used the boat 3 or 4 times a week. Over the winter I removed the lower unit and resealed, as I was getting a little water in the gear oil. That was the only issue at all last year. Ran some stabil through the motor, fogged, and put away for winter.

This season has been nothing but problems. First time out, had upper carb needle stick closed. Noticed this at the launch as the idle wasn't right. Pulled boat, replaced needle, seat and gaskets in all 3 carbs. I noticed my float bowls were all set completely different from one to the next. Set them according to my owners manual, which only shows closed position so I kinda guessed on open position.... How could it have ran so good last season with the floats all out of whack..?

Ran boat again. Idles perfect, I always fire it up once off the trailer then go park the truck. Pull away from the dock, begins to throttle up fine right through the spark advance, then falls on its face the minute the carb butterflys begin to open. There is maybe a second or 2 where it feels like it's gonna go, then nothing. It won't stall, but it won't rev. It's like it hits a wall.

Compression isn't great, but near 100 psi across the board. 3 seasons ago I did head and exhaust gaskets, 2 seasons ago it got a new cdi box, new coil, I run a large marine battery. This year, so far,

-New plugs
-New wires
-Link and sync over and over again thinking I'm missing somethin..
-Pulled flywheel and checked and set points as per manual spec
-Cleaned distributor and rotor contact points
-New coil (just for the hell of it)
-New carb needles and seats, and cleaned high speed jets according to info I found here
-New fuel lines. Even tried running from separate tank and bypassed all quick connect fittings just in case
-New fuel pump

I have never touched timing on this motor, so I can't see that going out of adjustment just sitting over the winter. It has great spark, and when I pull the plugs they have some oily residue on them, like they have in years past. That's about it. Any and all ideas or suggestions are more than welcome, I hate to say but I'm about to give up on this motor to the great disappointment of the family. It's expensive to work on, only good thing is there is a small shop near me that stilll stocks parts for it, and I am completely frustrated at this point.

Again, the minute the throttle advances past the spark advance and opens the butterflys, thats it. I can see fuel being sprayed into each carb, but honestly have no clue if it's too much, too little...

Thanks in advance.
 
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I turned them out approximately 5/8 turn and then adjust from there. I wasn't really sure what effect the low speed would have when throttled up, where do they leave off and the high speed jets take over?I really feel like it's an adjustment or linkage issue but it's literally driving me insane... Guess we're all been there..

One thing I haven't found any specifics on either is what the linkage come set at from the factory. I'd like to "reset" everything. Even in the factory service manual there isn't anything specific.
 
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Disconnect the remote control throttle and observe the throttle linkage on the motor as you manually operate it with your fingers (where the cable was attached, and motor not running). As you move it slowly from slow to fast position, it should first move the timer base to full advance with very little opening of the carb shafts. ONLY after reaching full spark advance, should the carbs open fully. If they open too soon, it will fall on its face, maybe even stall. Problem arises when timer base is sticky.

Cure: Remove, clean, and re-lube the timer base.

The breaker points, reverse cut-out ring, and distributor need servicing anyway.

The factory manual should cover all this.
 
Thanks for the quick response guys. I did remove, clean and lube base according to manual. Points are set to spec also. One thing that totally slipped my mind, when I had it apart the reverse cut out was worn down to nothing. I removed it.... Not good?
 
Just something to consider since you resealed the gearcase. I believe this motor has the rear bearing carrier that can be put in upside down. When this is done it blocks the exhaust off. The motor will idle, but not run well above idle. Hard to find if you don't know about it. I'll never forget my first one many years ago!
 
Thanks t2 definately something to double check after work today. I'm pretty sure the bottom of the carrier was labeled but it's been a few months. Never know.
 
The motor can and will run backwards, hence the reason for that spring.-----Yes 5/8 turn out is the initial setting.----You may be surprised at how the motor responds by opening them up 1/8th turn at a time.
 
Thanks racerone I will pick up spring tonight.There is an outboard shop in my area that has been around forever. Guy stocks everything, but is very selective as to what he works on these days. Guess I can't blame him.

As far as the jets I will play around with them on the water and see how things go. They will effect overall performance of boat? Luckily it runs enough to where I can idle back and forth from the launch.

Another question, should I double check my carb float levels? What effect will they have on boat acceleration?

It literally stops increasing rpm once the carbs start to open. Doesn't matter how long I hold the throttle up, it never catches.

Thanks guys for all the responses so far. I'm making a list of things to go over.
 
The wee boots on the distributor cap have been replaced ?----Any chance you have reed valves held open by mouse nest material ?----Run with a timing light to confirm spark on all 3 leads.----Water in the fuel ?----High speed jets in the BOTTOM of the float bowl confirmed to be clean ?
 
Yes sir the shop made me a set of new spark plug wires with all new boots. With carbs off I did take a peek at the reeds and they are all closed and clean. I used a piece of heavy-ish fishing line and can pass it through all 3 high speed jets. Fuel is a week or so old, even filled up a small tank with fresh mix when I ran it yesterday, no difference. I have checked spark at idle but not while trying to run on the water. I will add that to the list. Would it be worth trying to spray fuel into the carbs while I have my son work the throttle?
 
Yes spray some mixed fuel in there or observe fuel coming up the main nozzle and compare that to others.-----I am not there but it should be easy to figure out the problem----Have to ask if this motor was ever apart.----The first years of these had issues with piston skirts breaking off.---That pops a hole in the crankcase.----Have a look for that.----I have about 8 or more of these for parts.
 
I know the previous owner of this motor, he ran it right around 3 years also, so I can say for sure in the last 6 years it has not been apart. Prior to that though I don't know.

Not to sound like a complete idiot, but would there be a visible hole in the outside of the case? I will certainly thoroughly look this over tonight.
 
I am not there to look at it , but yes you would see a hole in the crankcase.-----3 spots possible where the rod big end rotates.-----Not saying that is the problem , but it is something to look for / consider.----Replacement pistons are much beefier.
 
Took a look after work with a flashlight and didn't see any holes. Also double checked lower bearing carrier, it is installed correctly. I won't be able to get back on the water with it until Sunday more than likely but I will keep you posted and appreciate all the advice up to this point. In the meantime gonna triple check linkages and get reverse cut off back in.

Racerone, you say have 8 or more of these for parts? Worst case scenario, are any of them for sale..? I don't know why but I have a strange attachment to this particular engine..
 
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Sounds good I will gladly let you know what I need from now on. I'd love to throw some business your way for all the help and free advice I've read on this site over the years.
 
I was working at a dealer when that model came out.-----It did have the " wow " look about it then.----68 was the first year for them------Had the wee teeth on the flywheel and starter.---Weak pistons.------Some issues with the bits on the bottom of the shift solenoid too.---They changed solenoids to operate valves soon after they found those problems.----They were very popular and Mercury dropped the 4 cylinder 65 to compete with their own 3 cylinder 65 hp.
 
Me too. The Evinrude version was named "Tiumph", and a triumph it was. It would run as fast as prevous V-4s and on less gas than a 33. Sure, it took a few years to get all the kinks out. Actually, I think we had more problems with the newer models that followed, than we did with the 55.
 
I actually had a 4 cylinder Merc 50 for 2 seasons. The Johnson 55 feels like it has more torque. It'll pull an adult on a tube behind my boat with me and 2 kids in it. Before this season would push the boat into the low 30's. While not a rocket, plenty fast for it's size. Hopefully I'll get it going again. I've only seen one other in my area. And we have a lot of boat traffic around here.
 
Trying to upload a picture but can't seem to get it.. Anyway I pulled carbs back apart last night and noticed the new bowl gaskets compared to the old ones are different. The old ones seal in the center of the carb around where the high speed jet comes up into the venturi, the new ones don't. Although I guess without a picture that means nothing... I'll try again to upload on lunch.
 
Yes you need that wee gasket to seal the nozzle.----That is the NOZZLE.----The high speed jet is in the very bottom of the float bowl !----384409 is the part #
 
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Racerone my rebuild kits that I bought locally did not come with that circular gasket that is pictured on this site when I look up that part number. Only the bowl gasket... Tell me that may be the cause of all my headaches?
 
Not sure you understand how exactly that carburetor and others work.-----But install that nozzle gasket and you will roar down the lake again.
 
Thank you sir. I don't know much about carbs at all which I why I physically brought it to the Johnson dealer when I wanted to rebuild... I'm thrilled to have this solved but pissed at the same time that I overlooked something so obvious. Thank you all so much for your time. I have a few choice words for the guy I bought my parts from though...
 
Not that I had any doubts but the boat ran like her old self tonight. Thanks again for all your help. Racerone I owe you beer if you're ever down this way.

The owner of the dealer I bought the parts from apologized and said he should have known he stocked those seals separate from the rest. He gave me a huge break on some other stuff I had wanted for a while.

Time to go try to catch some fish finally.
 
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