71’ 25hp Johnson still rough running

[davidmbv]

Hello, I have been working on this 71’ 25hp Johnson for awhile now. Weird things have come up as I’ve been fixing it up. I recently discovered a ground wire on one coil was installed wrong and wore against the flywheel and broke at the connector. I fixed the connections and re-routed them so they are clear of any moving parts. I took it out today and it seems to be hitting on both cylinders again but it still seems like it’s running rich and missing. I checked the plugs and they are a bit oily but not too bad.
Question: can running it on only one cylinder cause the carb to get gunked up? I cleaned it recently but then this unrelated coil wire issue came up and it began to run poorly due to no spark on that coil.
Also: coils, condensers, points all new . Could running it for short time on one cylinder cause points to get dirty?
thanks
Dave

 

[F_R]

No, running on one cylinder won't gunk up the carburetor.

No, running on one cylinder won't dirty up the points. But of course, dirty points can make it run one one cylinder.

 

[racerone]

^^^^---Round of applause for above post #2----Is the thermostat installed and not stuck open ?

 

[davidmbv]

Thanks. I ended up cleaning the points and checked gaps and they are set to factory specs. I did noticed one of the coils appeared to be a little off . It was rubbing against the magnet/flywheel causing a little wear. I adjusted it ever so slightly so it’s flush to the machined area. Hopefully that stops that issue and the coil will still function properly .
Also, I just pulled the t-state and it looks really crusty/rusty. I was able to compress it but the spring is dang stiff and the rubber gasket is worn. I’ll do some research to see how exactly it functions. It looks like a cheap part and I’ll likely replace it. I’m new to tinkering on these motors and not the most mechanically inclined but I’m willing to learn. I apologize for any stupid questions.
thanks

 

[racerone]

Put it in boiling water and see if it opens.----Then drench it in cold water and see if it closes.---Repeat as needed.

 

[davidmbv]

I’ll give that a try tonight. Thanks

 

[davidmbv]

Well the thermostat appears to be stuck closed. Tried sticking it in boiling water and nothing, then cold water and no change. Guessing that probably hasn’t help matters. Hopefully nothing got messed up with it running hot, if it was in fact overheating.
Im guessing a motor with a bad thermostat would cause some similar issues that I’ve been experiencing...?
also, I had a new impeller installed 4 month ago by a local shop when he serviced the lower end. It seems to spit water ok but I was suspicious about it getting too hot after running it at WOT then experiencing issues.

 

[oldboat1]

If it may be running hot, you don't want to run the bejeebers out of it. Infrared testers are pretty cheap these days. Motor should operate under 160F at the top of the head. (normal temp usually 120-140F, but can vary)