3hp OMC crankcase question

[billw]

Okay, I just learned something, about the dots! Now, I just had a Lightwin the other day and I was wondering how to synch it, because there was no mark on the cam….How do you do them?

Long live American manufacturing!

[outbdnut2]

I didn’t know about those dots either! I’ve done several by trial and error.
Dave

[Mumbles]

Evinrude Lightwins have a reference notch on the bottom side of the gas tank ring instead of dots on top.

Here’s a link to an old thread:

viewtopic.php?t=1400

[stanley]

All the ones I’ve worked on were accurately set and if there was any adjustment left it would only allow making it worse.Johnson instructions say there is a mark stamped on the cam where contact should occur,but I’ve never found one.

[fleetwin]

OK, so you are saying the engine runs the same with both carbs…Seems unlikely that you have two carbs with similar issues, but I guess anything is possible. You have checked the nozzle gasket and it is OK, but I would have expected opposite symptoms like others have said…
Have you tried running the engine without the air box? But again, I would have expected opposite symptoms if it was plugged up…
What year is this engine? Does it use a remote tank, does it have a fuel pump? If so, perhaps the fuel pump is leaking.
Does it look like the powerhead has been apart before, has the intake been messed with?
The only other simple thing I can think of is perhaps the exhaust is plugged up, but again I would have expected opposite symptoms.
Tell us more about the history of this engine, when was the last time it ran OK, or is it new to you and has always run this way….

[stanley]

The motor is a Johnson JW13.I got it for free because it was stuck.I know nothing of it’s previous life.Very nice cosmetically.I completely dismantled it and got it unstuck.Every thing looked good so I reassembled it with all new gaskets,rebuilt the carb and new coils etc.Has great spark and 80lb comp both cylinders.Tried with and without silencer.

[billw]

quote Mumbles:

Evinrude Lightwins have a reference notch on the bottom side of the gas tank ring instead of dots on top.

Here’s a link to an old thread:

viewtopic.php?t=1400

Well, I’ll be dipped. Where I worked when I was longer, we had some manuals, alright; but none were old enough to cover that. Thanks so much for that info!

Long live American manufacturing!

[billw]

Fleetwin mentioned the exhaust being plugged up. I like that one, especially if the relief holes where the water mist is supposed to discharge, are plugged up. I guess when you say it was stuck and it was totally dismantled, you’d have seen that the rings were free and that the exhaust ports in the cylinders were clear?

Long live American manufacturing!

[fleetwin]

How far did you pull it apart? What parts were replaced?

[stanley]

I took it completely apart.I split crankcase and checked crank,rods pistons and rings.Cleaned and completely rebuilt carb,and replaced coils,condensers and plug wires on mag plate.I am traveling now but plan to try a different mag plate when I return home and will definitely give the exhaust another look as well.

[Author]

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