Merc 300 out of time?

tomhath

Master Chief Petty Officer
Joined
Dec 5, 2007
Messages
814
The motor ran fine a couple of years ago. When I tried to start it this fall there was no spark. Took the magneto off, replaced the condenser and cleaned the points. Now it seems to have good spark at the plugs but won't start. If I give it a shot of starting fluid it backfires out the exhaust.

Is there a way to put the magneto or distributor cap on wrong? Looked like there was only one way to put it back together. I didn't pull the wires off the cap when I had it off. Smells like it's getting gas.

Is there a simple way to check that the spark is at TDC? Anything else I should be looking for on why it won't even sputter?
 
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Laddies

Banned
Joined
Sep 10, 2004
Messages
12,218
Re: Merc 300 out of time?

With the engine at TDC on #1 cyl the arrow on the mag drive pulley (not the one on the cover plate) should be on centerline of the pulley,flywheel mark and crankshaft. The mag has a blind spline and will only go in one way so thats got to be right. If the is red or green they are no good if it's tan or white they are good caps but might need washing out with hot water and dish soap then dried good.
 

rndn

Commander
Joined
May 20, 2007
Messages
2,323
Re: Merc 300 out of time?

It's not smart to spray starting fluid into a 2 cycle engine. It allows the engine to run dry. The only lubrication a 2 stroke engine gets is from the gas/oil mixture, something quick start does not have. If you want make up a spray bottle with the correct gas oil mixture and spray that into the carbs.
 
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