1981 35hp Johnson Seahorse

[kf7strng]

Hello,
I have a 1981 Johnson/Evinrude 35hp, Model# J35RLCIG, w/ tiller and remote controls. It idles rough similar to what the johnson in this video is doing :http://www.youtube.com/watch?v=-i3BAs3b76Q . The top cylinder is wet. The bottom cylinder is carbony/Sooty and not wet. Compression was checked today as well as spark by a very busy Johnson mechanic, who had enough time to determine both spark and compression were good.

It seems that when I use the tiller or remote controls to crack the throttle open the motor stumbles throughout the rpm range. However, When I manually open the butterfly with the throttle linkage on the side of the carb, the condition in the video improves. I have spoken to Joe Reeves ( seems to be the go to guy), and the johnson tech I mentioned, and both seem to agree that I need a carb rebuild. For the sake of completeness, Joe asked that I continue looking for answers in the forums. Does anyone have anything else to add?

 

[boobie]

Re: 1981 35hp Johnson Seahorse

I'll go along with the carb rebuild.

 

[Lil' Johnson]

Re: 1981 35hp Johnson Seahorse

Sounds more like ignition to me seeing as how the top cylinder is wet and all. I'm not sure what kind of coils you have but if they are the ones that have the primary wires that snap on to the little posts, those connections are very susceptible to corrosion, especially in a salt water environment. If they are corroded it is very difficult to restore the connection without replacing the coil and connector on the wire. When you rev the motor by the linkage on the carb and not the controls(or tiller), it is not advancing the timing at the same time so it may not be "loading" the ignition system enough to start breaking down. It is possible that the carb is dirty. I would pull it and check the gasket behind it and check the needle and seat for debris and the jets to see if they are clogged. If all looks ok, its probably ignition. Also check transfer port covers and make sure they are tight, any crankcase leaks can give a poor idle but will usually rev ok at least with no load. Check all the ignition wiring connections as well as you can as that seems to be the root cause of a lot of problems especially on older motors. Good Luck.

 

[kf7strng]

Re: 1981 35hp Johnson Seahorse

Lil' Johnson,
I dont want to go against two people with alot more experience than me, But i am leaning toward ignition/Electrical too. I say this because, the timer base/ plate thing that the stator mounts too doesnt seem too move freely/ return to its original position when using the throttle correctly. It looks like that was left out of my original post, but not what I originally spoke to Joe Reeves about.

What stumps me though is that if its a fuel problem, why can I crack the throttle and race the engine without it missing? It only stumbles like in the video at idle, and only stumbles with spark advance from the throttle linkage. Also, Like in the video, all tests, even the spark test were done out of water. The mechanic did the compression/spark test in his parking lot with no load on the engine. If I can add more confusion to the mix, the boat ran the same way in the water before i started all of this testing.

My original complaint was it would start, idle OK, and throttle up OK, but as soon as I got to 1/2 throttle the motor would fall flat on it's face, which is carb, right? or is that the stator not kicking over to the high speed coil? OR... could it be a reed valve problem?

 

[Lil' Johnson]

Re: 1981 35hp Johnson Seahorse

I really don't think its a fuel issue. If the timer base is sticking, that will definitely cause problems. I do know that if the timer base is not returning all the way it will act just like that motor in the video. Mine was doing the same thing because the timer base was too advanced at idle. I backed off the idle set screw(outside cowling on throttle control lever) until it stopped "sneezing" and then I had to adjust the idle mixture "screw" on the front of the carb to get a good idle again. A link and sync is really in order here but you need to fix the sticky timer base first. Try moving the timer base as far retarded as you can by hand while it is running and see if it idles better. Checking the carb is real easy so I would do that just to be thorough but it sure sounds like ignition trouble to me.

 

[kf7strng]

Re: 1981 35hp Johnson Seahorse

Thanks! I was messing with that outside screw today and we got it running... in the test bucket (plastic garbage can.. haha) It was running good so we took it out to the lake. and it didnt want to go again. I think i mentioned it had a tiller, which bent the damned outsiede idle adjustment somehow. I too believe its now time for a full link and sync, because now it idles well, just wont throttle up worth a damn because of that sticky base again. I dont know if it matters at this point, but the boat its sitting on is an old, but incredible 70's era Starcraft Super Sport V, approx 6 ft wide, and 16ft long. And I dont think a 35hp would have ANY trouble scooting this boat across the lake with two persons, just gotta get her running right.

I got my offical OMC OEM shop manual too thursday , so I have that as well as my clymer manual, so I should be able to get her going good! I'll try to keep you guys posted!

 

[kf7strng]

Re: 1981 35hp Johnson Seahorse

Well, heres an update:

My dad and I tinkered with the motor all weekend. Did yet another carb teardown, and sprayed carb cleaner and air all through the passages. We checked the float height, we made sure fuel was free flowing. We next pulled the flywheel and noticed what what we thought was oil. we cleaned that out, re lubed the armature base, checked the sensor coil, and charge coil for anything that looked out of place, found nothing and re-assembled. We did a full link n sync. We noticed that the throttle arm was broken ( little plastic round piece at bottom of shaft was broken. We repaired that and did another link n sync. Still runs terrible. It idles alright, and that pop, or snneze/kick is gone, but it will only once and awhile let you rev it in forward gear. In neutral it revs to the limiter (2500, or 3k.. whatever it is).. It revs in reverse too.. But not in forward. We also tested compression again, and got #'s (which the OMC mech. didnt tell me what the #'s were.) They were #1 125 psi, and #2 was 126 psi. Any one else have any guesses as to what it could be?, or is it time to actually take it to the mechanic and let him spend quality time with the old seahorse?

 

[AlTn]

Re: 1981 35hp Johnson Seahorse

an inductive timing light used on each plugwire can reveal a weak or intermittent spark..compression is good...time to check the spark for a 7/16" air gap jump with a spark checker, most auto parts places sell them for ~$10...the spark that was present for the mechanic may not be present now...you can spray some fuel mix directly into the carb throat and determine if it picks up or bogs...if you constantly squeeze the primer bulb < in the fuel line between the tank and the fuel pump >..does this affect the running in forward performance?

 

[kf7strng]

Re: 1981 35hp Johnson Seahorse

Thanks! I'll have to check that. Does anyone know if the throttle is limited by something in reverse, like it is in neutral? There is a little black tab that pops up when in neutral, and releases in forward, but I dont remember about reverse. Being at work now doesnt help, but im just trying to get a leg up on this problem!

 

[kf7strng]

Re: 1981 35hp Johnson Seahorse

All,
swapped coils with each other, and ran it with the choke..Runs great!, so... is it starving for fuel, and getting too much air without having the choke out? Which would mean i need to look at the carb, fuel pump, or fuel lines again?

 

[Daviet]

Re: 1981 35hp Johnson Seahorse

It sounds like a fuel delivery problem to me. When you cleaned the carb, did you remove the core plug on top of the carb and clean the tiny passages in there?

 

[kf7strng]

Re: 1981 35hp Johnson Seahorse

Daviet,
No, I didn't pull the core plugs or the lead shot,OR actually pull the jets, because i lack the tools to put them back. From what I understand you can make you own tool to remove the jets, but im not that creative, and I'm definitely not brave enough to pull the core plugs.

 

[Daviet]

Re: 1981 35hp Johnson Seahorse

You normally don't remove the lead shot, but the core plug should come out.
Do you have a factory manual, it will take you through it, if you are careful, you can do it.

 

[kf7strng]

Re: 1981 35hp Johnson Seahorse

Thanks. I'll look at it tonight, if it isnt raining that is. I'll keep you posted/ thanks for everyones help so far.

 

[kf7strng]

Re: 1981 35hp Johnson Seahorse

All,
I ran the motor in the can last night. Results were not as favorable as mondays testing. I couldnt get the motor to balacne exactly the same as it can on the muffs, because the bucket prevents it from sitting against the transom bracket. That seems to tell me that something is goofy with the float/jets/carb also.

Furthermore, I checked the fuel pump for leaks, didn't find any. I then pulled the pump apart, and took a quick look inside, i didnt see any varnish, or any blatantly obvious signs of damage, (may be a pinhole leak, idont know). I next left the carb feed line off of the pump and squeezed the bulb. Gas shot out every time i pumped the bulb, and only when I pumped the bulb. I put it all back together, and tried to run it again, and there was no change in behavior. The vent cap on the tank is open fully, and the bulb on the fuel line is always reasonably hard when the engine is running, and rock hard when priming before starting the engine.

I am about 99% sure that the ONLY problem i have is with my carb at this time. I have ordered a kit from here @ iboats, and I'll come back when I have that rebuilt and tested.

 

[kf7strng]

Re: 1981 35hp Johnson Seahorse

hey guys! Just thought I would let you all know, I got my carb tool in the mail, and took the high speed jet out. Had "a little" bit of junk in it.. even after running on a seafoam mix, spraying with carb cleaner, seafoam spray, and blowing out with comprressed air!

After assembly, running it in a test bucket (13 gal garbage can) we found she starts and RUNS ( even in gear up to 1/2 throttle to 3/4 throttle) well without the choke actuator linkage even installed! SO... Lake test time tomorrow! Wish me luck!

 

[AlTn]

Re: 1981 35hp Johnson Seahorse

you won't regret purchasing that jet removal tool...good luck on the lake

 

[kf7strng]

Re: 1981 35hp Johnson Seahorse

All,
Ran the boat on the lake today. It started well, ran well up to full throttle, but even at what should have been WOT, i wasnt getting full power from the motor. It would do about 8mph.. very happily I might add... but this motor should be capable of much much more. Local OMC tech suggested that it could be the high speed coil, however, I only have 1 charge coil unit, and one sensor coil unit. My question is, and I am inclined to BELIEVE the mechanic ( and for $30 +S/H I'll throw thw part at it), but.. if it only has the one charge coil (From what I understand "charges" the power pack to deliver voltage to the ignition coil), how does that single coil produce the high/low function?

By the way.. As far as I know, the resistance reading on that charge coil was good, and I didnt see anything visually wrong with the coil windings. Any thoughs? Joe Reeves... where are you?

 

[AlTn]

Re: 1981 35hp Johnson Seahorse

sounds like you're running on 1 cylinder...that 1 power coil does supply the voltage to the powerpack; i.e. it has no high/low function. I'd take an inductive timing light with me to the lake, leave the cowl< cover > off the engine, and hook the light to each plugwire in turn. Study the stobe light and you'll see if one or both are cutting out and not getting voltage to the plugs. You can also remove each plug wire in turn and determine if the engine will continue to run. Doing these will yield the info to go to the next diagnostic step.

 

[kf7strng]

Re: 1981 35hp Johnson Seahorse

Dad had me order a charge coil, and one ignition coil yesterday. Now, AlTn, I'll ask you.. Which do you think would be more plausible to go bad, one cylinders circuit in the power pack, OR... an ignition coil breaking down under load?

Also, everyone please forgive me if I am stubborn sometimes, I HAVE experience with outboards, and I base my theories on what has happened with them. Dad has an old trusty merc 86-88 25 hp, I want to say an 88 force, an 80's ( i think) chrysler 105, a Merc 200 (1995 maybe??) and last but not least, an Evinrude 9.5/9.5 something like that.

Now, that being said.. most people tell me when a merc fries a power pack ( they call them "switch boxes" i guess) that USUALLY you will see no fire at all. (i.e. if you have a v6, like dads 20, one bank wont fire but the other side, on a different pack will.) And unless I am mistaken, the OMC tech told me yesterday the same thing.. that IF the pack was the issue.. there would be zero fire.

Dads coming back up this weekend (parts will be here Thursday i hope!) So I'll get it tested out on the lake and see what happens.