96 4.3 Merc no start

[SeaRayboater95]

Hey guys and Gals,

My buddy says this boat was running pulling tubers. Shut it off and to load kids. Hard restart, then died shortly after. Towed back to dock.

Timing chain seems good. Crank moves about 3 degrees while turning crank by hand before rotor moves

Have fuel....seen squirt into carb
have spark....back fire trough carb at full throttle to clear fuel from flooded carb
Have compression, but varies from 135lbs to 180lb.

6-180 5-160
4-160 3-145
2-170 1-135
Dry cold cranking

Getting a spray from #6 while cranking.

Any help or direction would be awesome.

Thanks,

Ken

1996 Glastron 4.3 2bbl carb
F769949

 

[alldodge]

Spray from #6 and compression is high. Check if that's water in 6

 

[Lou C]

spray from the spark plug hole and the high comp test results suggest water in the cyls. Might be one or more than one.

 

[SeaRayboater95]

I used starter fluid to see if it would fire. It did not. At any rate, the spray smells like starter fluid. I'll try again later.

 

[SeaRayboater95]

spray from the spark plug hole and the high comp test results suggest water in the cyls. Might be one or more than one.

Are we thinkin' head gasket?

Ken

 

[Lou C]

It could be that or exhaust leaks. Investigate exhaust leaks first.

 

[Chris1956]

If you sprayed ether into the carb and she didn't pop, you have no spark at all. Check safety switch on shift cable and if that is good, troubleshoot ign system.

 

[SeaRayboater95]

If you sprayed ether into the carb and she didn't pop, you have no spark at all. Check safety switch on shift cable and if that is good, troubleshoot ign system.

Will doo. Thx

Ken

 

[SeaRayboater95]

It did backfire throught the carbs when I pushed the handle all the way down.

Ken

 

[Lou C]

Backfire when starting can be from a sticking intake valve, which can be caused by water in a cyl, that rusted the stem of the valve. I had that on mine when the head gaskets started leaking.
When it got bad it was very reluctant to start but would eventually start. Then it ran but with an obvious miss.

 

[Chris1956]

Backfire thru the carb is also a timing issue. My '88 had a mechanical advance on the distributor. I do not remember it ever sticking however.


My Thunderbolt ign module did fail one nice Saturday afternoon in November, coming back from a fishing trip. The ign was absolutely dead, one moment after it worked perfectly. Luckily a tow boat was passing me, and a radio call to him had another tow boat promptly rescue me.