Engine seems to be starving for fuel at higher RPM

[sterk32]

I have a 1981 Rinker with a 4 cylinder engine (2.5??) with a stringer drive. Last year had problems with backfiring thru carb, hard starting etc. So this year before putting in water I had the entire engine completely tuned up. All new plugs, wires, ignition components, timing set, new thermostat, fuel filter and carb filters replaced, fuel water separator added.

Ran great for a weekend and then while cruising a little over 3000 rpm seemed to throttle back on its own (as if no fuel) and then stalled couldnt get it restarted. I took it back to the shop that did the work and they told me water in the gas. They completely pumped the tank for me and went back thru the carb and filters again to clear everything out.

I got it back on the lake and starts up and idles great, I can cruise at low speed all day but once I start to push up 3000 - 3500 rpms it starts to throttle back again. If a pull back on the throttle and let it recover it wont stall and I havent had a recurrence of not being able to start it again.

Theres been a few time when it hasnt been an issue at all and I almost am thinking this seems to be when in calmer water so Im wondering if maybe its not even the speed but the choppier water that seems to bring on the symptoms.

Any help is greatly appreciated, thanks!

 

[Howard Sterndrive]

Re: Engine seems to be starving for fuel at higher RPM

I'd be looking at the anti-siphon valve where the fuel line comes out of the tank and that tube itself. sounds like yours has a piece of trash in it.

if that isn't it, I'd be suspicious of the fuel pump, then saturated carb float or settings

the wave connection says debris in tank though.

 

[superbenk]

Re: Engine seems to be starving for fuel at higher RPM

Agree on the anti-siphon. I fixed a similar problem by replacing mine. The old one looked ok just looking at it, but wasn't. They're cheap and pretty easy to change so worth trying before doing a lot of other stuff.

Did the pickup tube in the tank get removed & the little screen on the end of it cleaned?

 

[sterk32]

Re: Engine seems to be starving for fuel at higher RPM

Thanks for the input! I had wondered about the anti siphon, Ill pick up a new one and throw it on. Good to know someone has had a similar problem. Not sure if they checked the screen on the pickup while they were at everything else so Ill check that out too.

 

[sw33ttooth]

Re: Engine seems to be starving for fuel at higher RPM

Check this link out.Sounds like same issues.

http://forums.iboats.com/showthread....throwing+towel

not trying to hijack your thread

i highly doubt thats your problem, some one posted it on my thread i have the same problem as you. rpm drops like 500 then starts backfireing through the carb if i am doing over 4k. i know my gas is good and i replaced 2 water/fuel separaters. i'd think if you have a problem with valves you'd be able to hear it. my next step is probably a carb rebuild. unless your anti- siphon really does the trick, i'll be awaiting your response hopefully its good news.