Cant keep it running over 3000rpm!!!

[MikDee]

Re: Cant keep it running over 3000rpm!!!

i just went out and checked and there is no anti syphon valve, just the 90, the cutoff, and then the hose.

The 90 is probably the antisiphon valve (it was on one of my boats). You must make sure it is working properly, & not clogging up.

 

[fishingman220]

Re: Cant keep it running over 3000rpm!!!

ok, well i am going to go out there and take all of those aprat and see if i can find anything.

 

[FreeBeeTony]

Re: Cant keep it running over 3000rpm!!!

but once i went and got the truck it died all together and could not get back started.

Does this mean the engine will not start at all now?

 

[fishingman220]

Re: Cant keep it running over 3000rpm!!!

i am just getting ready to fire it now, it had fuel comming out the carb so i know if it doesnt start it will be no spark but i will see.

 

[fishingman220]

Re: Cant keep it running over 3000rpm!!!

ok, so i went out there and put it on the muffs, it started like normal, ran fine, reved fine and then after about 2 min, it slowly died out, and would not restart. i pulled the flame arrestor and the linkage, and worked the carb by hand, and it had a steady stream of fuel. when it was running, right at 1200 it would surge alittle bit, but then if you nailed it it wouldrespond fine. i am going to go check the plugs, it will take awhile cause they are a pain to get to, but any thoughts would be greatly appreciated

 

[TBarCYa]

Re: Cant keep it running over 3000rpm!!!

The problem on my boat was that the insulator on one plug was cracked. If you remove the plug and look at the white porcelain part, make sure that it is not damaged in any way as a damaged insulator will allow the ignition system to short against the block and not deliver spark to the cylinders.

While the plugs are out, running a compression test would be a good idea especially since they're tough to get to. The most important thing is that the numbers be consistent within 10% across all cylinders. Outside of that, what constitutes a bad compression number varies with each engine.

Here's a link to pics showing what spark plugs look like when certain conditions exist.

http://www.spark-plugs.co.uk/pages/technical/diagnosis.htm

 

[fishingman220]

Re: Cant keep it running over 3000rpm!!!

ok so today i tried the boat again, it started first try and ran fine for 2-3 min and then slowly died out. once it died i pulled the flame arrestor and looked in the carb and there was a bunch of gas in the barrels and the things that spit the fuel out were dripping, while the controll was at idle. just wondering if that is normal. the gas in the barrels was about 1/4in deep. i know alittle about carbs but not much so sorry about the lingo. should i have the carb gone through again??

 

[fishingman220]

Re: Cant keep it running over 3000rpm!!!

i think if it was a spark plug or wire wouldnt it be a steady miss?? it idles and revs fine, smooth as silk.

 

[MikDee]

Re: Cant keep it running over 3000rpm!!!

ok so today i tried the boat again, it started first try and ran fine for 2-3 min and then slowly died out. once it died i pulled the flame arrestor and looked in the carb and there was a bunch of gas in the barrels and the things that spit the fuel out were dripping, while the controll was at idle. just wondering if that is normal. the gas in the barrels was about 1/4in deep. i know alittle about carbs but not much so sorry about the lingo. should i have the carb gone through again??

Gas 1/4" Deep! I would think you need to go over that carb! It sounds like your float, & needle valve is stuck, or clogged up with debri, keeping the gas flow from shutting off normally. I'm surprised it would run, without misfiring, & shaking all over the place, or gas overflowing from the carb vent.

 

[fishingman220]

Re: Cant keep it running over 3000rpm!!!

ok well if i need it gone through, the rebuild kit that is in it, do i need another one? it only has an hour or two on it, is it salvageable or once you take it apart do you need another one??

 

[MikDee]

Re: Cant keep it running over 3000rpm!!!

ok well if i need it gone through, the rebuild kit that is in it, do i need another one? it only has an hour or two on it, is it salvageable or once you take it apart do you need another one??

If you are careful (don't break any gaskets) you don't need another kit. On that GM 2bbl make sure the float hinge pin is not getting hung up somewhere, and there's no debri on the float needle, or the well under it. You did check the carb filter screen behind the big nut on the fuel line? that leads directly to the float needle well.

 

[fishingman220]

Re: Cant keep it running over 3000rpm!!!

yes checked that before i fired it up. one thing i did notice was wierd was when i broke the hard line loose to the carb was there was no pressure. normally when i break that loose there is alittle pressure that squarts some gas out. i guess from the leaky gas inside the carb????

 

[fishingman220]

Re: Cant keep it running over 3000rpm!!!

Any other thought???

 

[hoot]

Re: Cant keep it running over 3000rpm!!!

carb floats are not usually part of the rebuild kit and are purchased seperately. the composite floats can get heavy with gas and not float up and the brass ones can get holes in them. hard to look at a composite float and say it is bad, it gets heavy. gas running into carb sounds like a float or needle issue.

 

[fishingman220]

Re: Cant keep it running over 3000rpm!!!

could that be what is making it die out?? i guess flooding insted of lack of fuel???

 

[SpeedJunkie]

Re: Cant keep it running over 3000rpm!!!

could that be what is making it die out?? i guess flooding insted of lack of fuel???

Yes, flooding will make a motor not run.

 

[fishingman220]

Re: Cant keep it running over 3000rpm!!!

would that make the condition that i had on the water, where it wouldnt run above 12-1500rpm??? it ran at that speed for almost 45min to get back

 

[wca_tim]

Re: Cant keep it running over 3000rpm!!!

well... it's a mechanical fuel pump, right? so the higher the engine rpms the more fuel it pumps... could be that at the rpms you're talking aobut you're ale to burn the majority of what's getting puped in there, but when you run it up a little the engine isn't able to use the increased fuel flow...

does the oil smell like gasoline and look a bit thin?

 

[remauto1187]

Re: Cant keep it running over 3000rpm!!!

This is classic needle and seat not meeting up with each other. You got flooding issues. Check a spark plug. They will be really wet of gas! Always replace your floats during a carb rebuild! They are inexpensive and will get heavy with age!

 

[fishingman220]

Re: Cant keep it running over 3000rpm!!!

ok thanks alot guys!!