1st Time Boat Owner with a Couple of Questions

[bwsbar]

I recently purchased a 1990 4.3L Cobra with a Rochester 4BBL. Since I have had the boat, I can not reach recommended WOT Rpm's (4400). At WOT, I am only reaching 3000-3400 r's. For piece of mind, I had the carburator rebuilt. Still no change in WOT rpm's. But now, my idle rpm's are too high. At low idle they are 1000. The tech book says they should be 500. Tried to back-off idle screw, but made no difference. Any suggestions? Thanks

 

[Limited-Time]

Re: 1st Time Boat Owner with a Couple of Questions

Did you adjust the idle mixture screws and check the timing before you attempted to set the idle................if you did it sounds as if the rebuild did more harm than good.................as for the lack of RPM as WOT...........................do a search there's a list of things posted here to help sort it out..............Also DO NOT run the boat before you correct the Idle thing.........1000 RPM is way to high to engage the OD with out doing costly damage...........and BTW welcome aboard................

 

[chiefalen]

Re: 1st Time Boat Owner with a Couple of Questions

Ok before you did the rebuild did you check all the filters?

The one in the fitting that goes in the carb, the one in the fuel pump if you have one there, the fuel pickup screen in the tank. The fuel/water seperater, i know i spell badly.

The anti-siphon valve checked? And tank vent.

If all ok than when was a full tune up done?

Timing ok?

Fuel pump 4-6 pounds?

That carb got to be rebuilt again.

Not all carbs can be saved. Those adjusting screws,gently going in don't bend the tips out about 2 turns to start.

After everything is set right in the driveway and problem persists than pull the plug on the esa on the water and if it solves the problem of w.o.t maybe new esa.

Don s posted a fix for it without the esa different way to wire it as a merc.

Oh isn't that motor supposed to idle 650-700. In gear.

Isn't w.o.t 4200-4600 rpm. Do not shift it at 1000 rpm

 

[bwsbar]

Re: 1st Time Boat Owner with a Couple of Questions

Thanks, for the replies. I fixed the high idle problem...sticky throttle linkage. Hope to solve my WOT rpm problem this weekend.

 

[ATAYLOR61822]

Re: 1st Time Boat Owner with a Couple of Questions

Have we checked the prop?

 

[derekpfeiffer]

Re: 1st Time Boat Owner with a Couple of Questions

My experiences has been the prop or the timing.

Good luck,
Doogie