1990 50HP Force Starts but won’t stay running

[Engagemuff]

This is a bizarre issue I cannot seem to diagnose. The motor is new to me, and I’ve never had it running on the water.
I currently have it setup in a 55g drum.

It will start and idle for about 30 seconds. Once it fires and runs for 30 seconds, it will not start again until the next day / several hours.
Seems to turn over strong.
Choke doesn’t seem to help.
Manual throttle doesn’t seem to help.

So far I have-
Changed plugs
Cleaned carb w/ new pin and gaskets
New impeller

Note: when I first got the motor it was running for 5 minutes and the heat buzzer came on. I immediately shut it down and that is when I changed the impeller. Since then, it’s been running terrible.

What am I missing?

 

[Nordin]

First of all check for good spark at both cylinders, then check compression.
If you have compression and spark then check the flywheel key.
If it is shared, then the timing is off and it would not start even if spark, compression and fuel delivery is okey.

 

[jerryjerry05]

Welcome!!!!
Sounds like the floats not set right or the needle is locked in place(closed), take the carb apart and check the floats level.
There's a bunch of things that can help in the first few posts in this forum.
Read them and see if you can find how to set the float??

 

[Engagemuff]

First of all check for good spark at both cylinders, then check compression.
If you have compression and spark then check the flywheel key.
If it is shared, then the timing is off and it would not start even if spark, compression and fuel delivery is okey.

Thanks for the suggestions guys!
Spark test was great top and bottom.
The compression test. Not so great.
102 psi lower
76 psi upper

Is it worth chasing further, or am I throwing money at a bottomless problem?

 

[Engagemuff]

Thanks for the suggestions guys!
Spark test was great top and bottom.
The compression test. Not so great.
102 psi lower
76 psi upper

Is it worth chasing further, or am I throwing money at a bottomless problem?

I should add this was a cold reading.

 

[jerryjerry05]

Cold or hot shouldn't make much difference.
You remove both plugs when doing the test?
They sell snake camera's for most new phones, 16$ ebay
Get pics of the bore from the low cylinder.
Might just be a bad head gasket????