1976 35 hp evinrude top plug fowling

[mrcrw009]

Well this engine sat in a builing for about 15 years and i pulled it out and we got it running with just some new gas, cleaned the points and that about it. Well after messing with it I have installed new points, removed and cleaned the carb (basically took the bowl off and low idle adjustment screw and blew out with carb cleaner). The ignition system checks all seemed to be correct. The engine starts good and runs alright at low idle most the time but when i advance the throttle it instantly starts coughing and sounds like its missing which i think it is because the top plug keeps fowling no matter what i do. I already swapted the coils and plugs so thats not it, sorry for the long post but does anybody have any ideas for me i am running out of ideas. Thanks

 

[oldcatamount]

Re: 1976 35 hp evinrude top plug fowling

Sounds like a bad wire or connection to the number 1 piston. Check for a loose ground screw and look for signs of arching. If you can get it to run when it's dark, that'll show you the arching. It sounds like you may need to replace the plug/coil wires. After all, they are 30+ years old and brittle.

 

[mrcrw009]

Re: 1976 35 hp evinrude top plug fowling

ya you may be right, i have kinda looked at all the wiring and connections. The only thing is that i can swap coils and the leads and it only happens to the top cylinder.

 

[mrcrw009]

Re: 1976 35 hp evinrude top plug fowling

and i will try running it in the dark that is a good idea

 

[steelespike]

Re: 1976 35 hp evinrude top plug fowling

Be sure the carb roller picks up on the stator cam right.

 

[mrcrw009]

Re: 1976 35 hp evinrude top plug fowling

ya i was wondering about that i mean it looks like it is picking up right but what should i be looking for

 

[boobie]

Re: 1976 35 hp evinrude top plug fowling

Check your point settings again and make sure you have no slop in the mag plate. These ignition systems were very touchy. Worst ones OMC ever built.

 

[mrcrw009]

Re: 1976 35 hp evinrude top plug fowling

so i just pulled the vaccum line off that comes from the bottom of the intake valves and goes to the fitting right above the fuel pump and it was full of fuel is this correct does not seem right to me

 

[oldcatamount]

Re: 1976 35 hp evinrude top plug fowling

Yes, I think it is right. I believe it's the re-circulation line. It's function is to return un-burned fuel back into the motor and with a motor that's not running on both cylinders like yours, there would be a fair amount of fuel in the line.

 

[mrcrw009]

Re: 1976 35 hp evinrude top plug fowling

ok so i just re gapped the points and they are good the spark plugs jump a good blue spark about 7/16 of an inch, so i mean the spark looks good it just seems like the top cylinder is getting flooded. It seems like to me the timing on these things are fixed right? now that re-circulation line has a check valve on the intake valve side and it looks fine but if that check valve was not working the fuel would stay in the cylinder correct? and another question if it was a carb prob both cylinders would be running like crap so i don't get why its just the top one getting fouled. by the way thanks for all the help guys i have been fighting this for a while now.

 

[mrcrw009]

Re: 1976 35 hp evinrude top plug fowling

oh and i have been running it on muffs the whole time too, should i get a big tub of water or something and try to run it on that also?

 

[oldcatamount]

Re: 1976 35 hp evinrude top plug fowling

So, you have good spark at both plug wires but one plug seems to foul. Switch those spark plugs and run it again. If you have a bad spark plug, the problem will now be on the bottom cylinder. If that's the case, change both of the plugs and be sure you have the right ones and they are gapped right. Sorry, I don't know the number for the right plugs, but, someone here will. I believe the gap is .030.

 

[mrcrw009]

Re: 1976 35 hp evinrude top plug fowling

ya i have already swapped the plugs and coils around and it stays with the upper cylinder

 

[mrcrw009]

Re: 1976 35 hp evinrude top plug fowling

you know another thing is that the crankshaft oil seal up top is leaking pretty bad so i thought that point was getting wet but i have cleaned it off a couple times and ran it and it coughs instantly so i didn't think that was it because it takes a min for the oil to get worked up in there, granted it does leak really bad and i'm in the process of getting the part to change it.

 

[bktheking]

Re: 1976 35 hp evinrude top plug fowling

so i just pulled the vaccum line off that comes from the bottom of the intake valves and goes to the fitting right above the fuel pump and it was full of fuel is this correct does not seem right to me

If it's full of gas it's not a vacuum line, more like a lubricant feed for the top bearing, it's supposed to have gas in it.

 

[mrcrw009]

Re: 1976 35 hp evinrude top plug fowling

no i have not checked compression i don't have the tool to do it but the compression feels pretty good though

 

[mrcrw009]

Re: 1976 35 hp evinrude top plug fowling

i noticed that the flywheel timing marks do not line up with that black pointer on TDC or anything else it is way off on the top cylinder and the bottom cylinder. also does anybody know how to check the timing advance

 

[oldcatamount]

Re: 1976 35 hp evinrude top plug fowling

Try doing a "link and synch" adjustment, where the throttle linkage is adjusted so that the cam roller reaches the "hash" mark on the cam at the exact same time as the throttle plate just starts to open. You can make a tool from an alligator clip and a small piece of wire where you clamp the alligator clip onto the end of the throttle plate rod. The small piece of wire attached to the alligator clip will make it easier to see the rod move as the throttle begins to open. The roller, hash mark, and throttle plate all have to be synchronized with each other. Other than your points settings, that's about all there is to "timing" the motor.

 

[mrcrw009]

Re: 1976 35 hp evinrude top plug fowling

ok cool i'm going to go try that. another thing you guys said was to look for slop in the timing plate and i took it off and it does have a little slop so the points change a little so i'm messing around with that, i read that for some reason that usually affects the top cylinder, don't ask me why.

 

[oldcatamount]

Re: 1976 35 hp evinrude top plug fowling

You say you have changed the points and coils so you've had the flywheel off a couple of times. Did you look at the Woodruff key when you had the flywheel off? The Woodruff key needs to be installed in the crank slot "vertically parallel" with the crank shaft. If it's not, and installed on a slight angle with the taper of the shaft, this would throw off the timing a bit. Also, have you been using a torque wrench when you re-install the flywheel? These two items can screw up the timing if not done right.