mercruiser 3.7 stalls after warm

[driordan007]

I have a 1989 Wellcraft v-20 with a 3.7 mercruiser. It starts up and leaves the dock just fine. Once we stop and sit for awhile it will start up again but stalls when put in gear and we try to accelerate. The carb has been rebuilt 3 times. All electrics have been changed(tune up kit, plugs, wires,dist cap, condenser and coil) and the problem continues. I've been told the carb may have an internal crack. Can anyone solve this mystery for me?

 

[Bondo]

Re: mercruiser 3.7 stalls after warm

The carb has been rebuilt 3 times.

Ayuh,... My Guess is,... The Carb is Junk,+ needs replacing....

The next time it Stalls,... Figure out whether it's lacking Fuel or Fire...

 

[rodbolt]

Re: mercruiser 3.7 stalls after warm

carefully inspect the shift cable where it wraps around the exhaust pipe.
have someone observe the shift cut switch when the problem starts,no movement should be observed at the switch.

 

[sdoomaha]

Re: mercruiser 3.7 stalls after warm

When it stalls.....can you get it restarted? What does it take? How does it run after you get it restarted?

Like Bondo said...check to see if you are getting fuel when it stalls. My 470 used to occasionally vapor lock when running it hard on a hot day. If I restarted it right away, no problem...but if I let it sit for 5-30 minutes it would start, I would put it in gear and it would bog down. Sometimes I could pump the throttle furiously and it would work through it, but most times it died. Would require considerable cranking of the engine and pumping of the throttle to get it restarted. Learned to let the boat idle for a while after a hard run on really hot days and it hasn't happened again.

Hopefully it is something simple for you....good luck.