Top cyl fouling 1977 Rude 35hp

[Marinetoflyboy]

Hey everyone. I have a 35753H model that is super clean. It ran great when I got it last yr. After a few fishing trips it was running on 1/2 power under load. Turned out to be a cracked coil.
Put in new coil and thought problem solved..... Noticed fuel leak from my non-VRO pump. Rebuilt it & still leaked! After trying a few other fuel pumps it was perfect. Ran it today for about 20 min WOT and slow speed. Testing reverse it seemed sluggish so put it back in forward an punched it. It struggled and felt exactly like last years issue (running on bottom cyl)
When I got it home ran her in a bucket and pulled plugs. Top was wet and bottom dry. Pulling top wire running proved only running on 1cyl. New coil so now I'm back to square 1!!! No clue as to shape of points as haven't taken off flywheel yet.
Comp seems good and spark, who knows. I got a bad jolt last time as holding onto a metal boat standing in a puddle isn't smart pulling plug wires while running. Sorry so long but I wanted the most info out here to help

Any suggestions?
Thanks so much
Ryan D
USMC

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

What could have changed in the short time I ran it today? Temp? Also have new starter, electric choke, and a bunch of new gaskets (carb/ silencer/ intake manifold) seafoamed carb. could it be lean/rich?
I was thinking I had won this battle today :-( I'm chasing my freakin tail

 

[BonairII]

Re: Top cyl fouling 1977 Rude 35hp

Are both coils new? If not, swap the coils and see if the problem follows the coil.

Possible that a coil is failing when it gets warm.

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

Thanks for the reply. I will do the switcheroo tomorrow and see what happens. I will post findings. Btw only replaced the 1 coil to the top coil

 

[F_R]

Re: Top cyl fouling 1977 Rude 35hp

Well, I can tell you one thing it is NOT....it is not the points, because it doesn't have any. In fact, there is nothing under that flywheel except a stator, which either works or doesn't work. And it fires BOTH cylinders. So, it is working.

Test your spark. Should jump a 7/16" open air gap. Should also knock you right out of your shorts if you get hooked up to it.

I would have guessed fuel pump, except you talked me out of it. How about leaking head gasket or other water leak? Getting water on that bad plug? Finally, how is the compression? Tested it?

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

Thanks FR Stator! Right! Don't I feel like a Tool! Can you tell it's my 1st o/b? well you saved me from some taking off the flywheel. As far as compression, I really don't have the means to check it but I assume it's good as it ran awesome yesterday. And as for the fuel pump it's new (used) it could have a bad diaphragm leaking too much gas into that cyl. I'm about to swap the coils to see what happens. You can eat off this motor. Such a shame it's screwing with me like this. But I would know even less about the motor if I didn't have these problems. I still have extra parts from 3 fuel pumps and rebuild kits so if I need to I can rebuild this latest one with new gaskets. I'm fishing today regardless. It can still get me out there and back on one cyl. Plus as a backup I have 2 trolling motors. Above mounted motor guide 67lb and a little minn kota 28lb on the back with 2 new marine batts

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

I just removed the bottom coil and put the brand new one on the bottom and wouldn't start (run) at all. Put the other on top so they are flip flop from yesterday and won't start

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

I just put them back the way they were and it fired right up. This should tell us something right??

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

Also I have a good amount of oil in my trash can I'm running motor in. Is this normal? Or is this a clue to my problem or perhaps another issue? It's never ending :-(

 

[OptsyEagle]

Re: Top cyl fouling 1977 Rude 35hp

You will always have oil and gas in the barrel when you run a 2 stroke, especially when one cylinder is not firing and probably just passing the gas and oil along and into the water. So no, don't worry about that.

You said you were running on only the bottom cylinder from your plug removal test. Then you swapped the bottom plug to the top cylinder and you got nothing. Then, I assume you put the top plug on the botton cylinder and still got nothing. My question is, did you also swap the clips. If not, no motor will run if all that is swapped was the plug boots. In that configuration the motor would fire when the cylinders are both at bottom dead center and off course do nothing.

If you did swap both the boots and clips, it would indicate to me that you must have two seperate problems. Perhaps I am missing something.

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

Thanks for your input. To clarify I was trying to see if the new coil was now bad so I reversed them (flipping top coil with bottom coil) and it would not run. As for clips, I'm not sure what u mean. I had cut and spliced wire to the clip u may be referring to when I installed the new coil to the top cyl. I'm guessing these coils need to fire in some sort of order or configuration. But I see what u are saying. Other than the individual grounds for each coil the other wire marked on the connecting plug for both has wires marked 1 & 2. Wow my ignorance and oversight scares me sometimes. So this time when I reverse the coils I will indeed make sure the corresponding wire from harness is going to be flipped from top to bottom as well. Stupid stupid stupid rushing things :-(
And as for oil in the water thanks I had suspected it was normal under the cercumstances. Thank you. This site has educated me daily. I will post my findings

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

NOT THE COIL! I swapped the 2 coils again and the appropriate wires and it is definitely the top cyl again. So the coils are ruled out. Starts right up no choke. Now what? Should I bother taking the fuel pump apart to see if too much fuel is getting in top cyl. We're getting close! thanks everyone
Ryan

 

[OptsyEagle]

Re: Top cyl fouling 1977 Rude 35hp

OK, so you can rule out the coils and your powerpack and because your carb drives both cylinders, we know that is OK as well. I can't remember if you ever switched the spark plugs or put in new ones but it is so easy, if you didn't, give it a try and see if the problem remains.

The other culprits that can make that motor's top cylinder fail is a blown head gasket or scored cylinder wall, which can usually be verified with a compression test or removing the powerhead and looking at it. You said the plugs were oily and wet so I doubt it is a water intrusion problem.

It could be flooding of that cylinder from your fuel pump. You could remove the two screws that hold it to the powerhead and squeeze the primer bulb to see if you observe any leaking fuel. Take a look at the gasket that seals it to the powerhead to see if it has any visual problems.

It can also be the upper crankcase seal, which is under the flywheel. All you can do there is simply change them and see if things improve. It can also be your reed valves for that cylinder. If there is something that got sucked in that is keeping them from closing properly you can sometimes see some fuel spitting out of the carb throat when it is running.

Those are my thoughts. Perhaps others have some ideas.

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

I will have to do a compression test if I can get my hands on a tester. I called Atlantic Outboards here in my state and the guy was not so helpful. Just asked about compression. Also said if it was a compression issue he said get a new motor! Thanks for nothing.

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

Thanks OpsyEagle. I will check out the reeds an also the possibility of fuel leaking when I take to 2 long bolts out from the bottom of the pump. It's a new gasket so idk have more I can use. Crap that means starter off then carb off to check reeds. Hahaha

 

[OptsyEagle]

Re: Top cyl fouling 1977 Rude 35hp

I will have to do a compression test if I can get my hands on a tester. I called Atlantic Outboards here in my state and the guy was not so helpful. Just asked about compression. Also said if it was a compression issue he said get a new motor! Thanks for nothing.

Sometimes bad compression signals a motor that is now only useful as a boat anchor and sometimes it doesn't. If it is a blown head gasket it is only about $20 bucks and pretty easy to change, so no, bad compression does not mean a junked motor. If you do remove the cylinder head, look at the flatness of the head as well. They can warp over time, especially if they were ever overheated and that can kill the compression in a cylinder. You will want to flatten the head before you put it back on anyways.

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

I pulled the fuel pimp off and ran it for a few seconds. It appeared that I was getting a pulsating mist of fuel from that center threaded hole (pulse) I believe but motor died pretty quick. As for the plugs I swapped them top to bottom and no change so new plugs although cheap I doubt will change anything. Still need to check out those reeds

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

For a 1977 this Motor is prestine. And the old timer who owned it took very good care of her. Garaged and it looks brand new inside and out. When I purchased it, it had been sitting outside uncovered for 3 years by the 2nd owner who said he never even took it out once. I'm so frustrated I'm about to break down and bring it to a pro. Pissed!!!!! Talk me out of giving up %#??^%~!!!!!!

 

[OptsyEagle]

Re: Top cyl fouling 1977 Rude 35hp

I pulled the fuel pimp off and ran it for a few seconds. It appeared that I was getting a pulsating mist of fuel from that center threaded hole (pulse)

Not sure what you mean by center threaded hole but the center backside is where the problems can begin . Was any fuel leaking out the back at all? You don't need to start it up, just connect the fuel hose and squeeze the primer bulb. If the diaphram is toast, fuel can leak out of the back. That fuel will get sucked into your top cylinder and flood it sure as the day is long. Sounds like that may be your problem.

 

[Marinetoflyboy]

Re: Top cyl fouling 1977 Rude 35hp

I will check. Like I said much earlier I did have the fuel leaking there before after changing the top coil. I also got a use fuel pump and put it on before the UPS man even left. This one does not seem to be leaking (atleast not externally like before) I'm going to take apart this fuel pump and see how it looks. I have a rebuild kit.