runs for a few seconds and cuts out

[TomB]

Hello all,
I believe i have a carburetor issue.
backgroud:
boat flooded, water in motor.
cleaned up, engine head was found to have a water jacket breach. head replaced. 90 compression in all four cylinders.

while working on replacing the head. a co-owner of the boat decided to rebuild the carburetor with a moyer rebuild kit.

threw everything back together and the engine starts (with choke out) runs for a few seconds then cuts out. wait a few minutes, same thing.
i can keep her going for a little longer by spraying some carburetor cleaner in the intake, or pouring a little gas prior starting into the carburetor. I messed around with different idle mixture settings and throttle settings and some difference but no real results.

drained the float bowl, cranked and ran for a bit after pouring a little gas in carb. checked float bowl again and full of fuel, so manual fuel pump seems to be working.

i pretty sure I have good gas, had flushed gas threw after throwing all together and she does run for a few seconds.

so i now have the carb off and going to take apart. I have a few questions:

1) gasket sealant? i do not see anything in the moyer manual in regards to the gasket and using sealant. anything i should know about this?

2) the moyer manual mentions the main jet can easily get damaged. How do i tell if the main jet has been damaged?

3) thread sealant. should this be used anywhere?

4) anything else i should particularly be looking for.

any other advice greatly appreciated.
thanks,
tom

[JOHN COOKSON]

Could be an air leak.
When you get the carb apart and cleaned up hold the two halves together to a light source and see if you can see light through the two halves (no gasket). Also is there any rocking or "funny" fitting between the two halves?
Do you have a PVC valve on the engine?

TRUE GRIT

[ndutton]

2) The Moyer manual mentions the main jet can easily get damaged. How do i tell if the main jet has been damaged?

Please specify where this is mentioned in the Moyer manual. I found an idle jet caution but no such mention of the main jet being susceptible to damage.

4) anything else i should particularly be looking for?

I suggest the Moyer Marine video on carburetors.

https://moyermarine.com/product-category/videotechtips/

[roadnsky]

...the engine starts (with choke out) runs for a few seconds then cuts out.

Tom-
Are you leaving the CHOKE engaged after the engine starts?
If so, that would be a reason for it stalling.
On a clean, proper mixture adjusted carb, you should only need the choke to start it and then dis-engage the choke.

Some answers to your questions...

1) gasket sealant? i do not see anything in the moyer manual in regards to the gasket and using sealant. anything i should know about this?
I personally do not use sealant on my carb when rebuilding. YMMV

2) the moyer manual mentions the main jet can easily get damaged. How do i tell if the main jet has been damaged?
Likely referring to being careful with your screw driver when loosening or tightening the brass head in the slot. (See the pic)
Also, there is a small washer that goes in there. Be cautious not to lose it.

3) thread sealant. should this be used anywhere?
Again, I personally do not use.

4) anything else i should particularly be looking for.
What John suggested being careful of air leak or mismatched halves.

Finally, you may be a good candidate for Don's 12 buck video on the carb.
Worth it twice over IMHO...

EDIT - Neil types faster than I do.

[roadnsky]

TomB-
Are you still out there?
Can you post an update for us?