Engine turns over slow if at all

[Maclin]

Re: Engine turns over slow if at all

Yanking heads will not fix this. Fuel in the crankcase comes from the carb fuel bowl leaking into the intake manifold and around some open valves then seeping past the rings, or from a failed mechanical fuel pump dumping directly into the crankcase. You say you have an electric fuel pump so that leaves only the carb. It can be too full, maybe the needle/seat cannot seal against the pressure from the fuel pump and leak fuel in and it overflows into the carb bore after it has been run. A carb can also leak from the bottom, some models have plugs in the bottom of their carb bowls, those are just glued in and can leak after a while.

Can you see any fuel seeping out from the butterfly plate shaft bushings?

 

[dingdongs]

Re: Engine turns over slow if at all

is your fuel tank above the height of the engine as there seems to be a lot of fuel getting in the engine and its going up hill.is the pump still pumping after the engine is off?float may be set wrong and allowing excessive fuel to fill bowl and overflow down the throat of the carb.the only way is to find the fault as this is not correct.a manual is a mst for the relevant info for float setting and valve seating which lets the fuel in the carb.

 

[texasvet54]

Re: Engine turns over slow if at all

Thanks for the recent replies.

The fuel tank is at the same level as the motor, but the pickup tube in the tank is probably 8 to 10 inches below where the hose attaches to the fuel/ water separator mounted on the engine.

As far as the carb goes, when the marine shop re-positioned the float that was installed improperly during their rebuild, i saw that he didn't measure it's position.

Texasvet

 

[dingdongs]

Re: Engine turns over slow if at all

as the tank is fairly high the float will have to be reset and the valve on its seat has to be proved its working.if you strip it down it will not be hard to prove that it is sealing. its having a free syphon effect as the tank on most are in the bilge.an anti siphon valve will cure your symptoms but you'll have to look for the correct one .heres a sample; http://www.marinemechanic.com/asof-8-29/antsiphon.htm
this style should fit on your fuel seperator as it has the same thread on the inlet side. http://www.moellermarine.com/aftermarket/fuel_systems/valves/

 

[texasvet54]

Re: Engine turns over slow if at all

as the tank is fairly high the float will have to be reset and the valve on its seat has to be proved its working.if you strip it down it will not be hard to prove that it is sealing. its having a free syphon effect as the tank on most are in the bilge.an anti siphon valve will cure your symptoms but you'll have to look for the correct one .heres a sample; http://www.marinemechanic.com/asof-8-29/antsiphon.htm
this style should fit on your fuel seperator as it has the same thread on the inlet side. http://www.moellermarine.com/aftermarket/fuel_systems/valves/

Well, a buddy of mine who's made a living as both an automotive mechanic and diesel mechanic took a look at my problem. We didn't pull the carb apart as we were short on time. He had me turn the engine off as he looked in the base of the carb and he didn't see any fuel pooling in the base. He suggested that as part of the troubleshooting, I should put an inline cutout valve prior to the fuel/water separator. If I read your post right, I think that is what you are suggesting with your anti-siphon valve. So, while none of us have said with certainty that it is the carb, we are looking at the fuel system as being the culprit, not the engine itself at this point.

thanks,
texasvet

 

[dingdongs]

Re: Engine turns over slow if at all

hopefully without the stripdown to the float and its valve and seating not being done correctly that would be the easiest scenario and cheapest to prove a point.

 

[jze1212]

Re: Engine turns over slow if at all

Sounds like a new carb is the answer..

 

[texasvet54]

Re: Engine turns over slow if at all

Sounds like a new carb is the answer..

I ordered a brand new carb a few days ago. Hopefully I'll have it in a week and this nightmare will be over.

texasvet