84 evenrude 35hp low rpm under load

[rabidhunter66]

This is what i have done so far. Carb butterfly adjusted per manual and lines up perfect between the marks. Linkage set screw set to spec.

Carb rebuilt
New fuel lines
New fuel filter
New correct plugs. Gapped to .040 per book
New coil packs.
New non ethanol 50-1
2 tanks with sea foam
New prop

A high speed jet didnt come with the rebuild kit. I will take the carb off again next weekend and try and clean it again. But when i rebuilt it a few weeks ago it looked clean as a whistle. Also neutral idol. Drops to about 600rpms and it stalls out. Is there an adjustment for that? Low speed idle needs a little more work also. But thats just a matter of taking the time on the water but it will come in. TIA.

 

[rabidhunter66]

Also new tank and lines

 

[rabidhunter66]

Just tried it again. Started and warmed up for a few minutes eased into the throttle and it seemed to struggle a tad but came up ok and ran at about 3700rpm. Which has been good for this boat with a 10-15 prop. About 19-20mph. Then i shut it down and repeated and wouldnt even hit 3000rpm. Something has to be floating around in there. The only thing i havent changed is the high speed jet and the fuel connector on the engine itself.

 

[rabidhunter66]

Compressiin is 120 on both cylinders

 

[racerone]

Do you have spark on both leads ?-----How big is the boat ?----How much does boat weigh ?----Are you sure the tachometer is set correctly?

 

[rabidhunter66]

Yes on spark and tested. 16ft alumicraft side console. Home made plywood decks and trolling motor. Tach is set on 6p (pulse). One point ill get 3700rpm. Take it out later and barley get 3000rpm.

 

[rabidhunter66]

I will add that i have had the boat for 3-4 years and with the exception of last fall i have had the motor put up by a local shop for the winter and covered and stored im my yard. Havent had an issue with it till this year. My fault im sure for neglecting it last fall.

 

[rabidhunter66]

Ill also add im no mechanic. I have the Seloc and Clymer manuals. I have read the "secret" post at the top.

 

[racerone]

Checked the flywheel key ?

 

[rabidhunter66]

I can. What is the significance of that? How is it affecting the jump in RPM's?

 

[racerone]

It controls the timing.

 

[rabidhunter66]

Ok ill check it out. Thanks!!

 

[jimmbo]

10 X 15 prop? that was only for feather weight hulls. 3700 on an engine with a WOT 5000 - 6000 rpm range is not good. As asked earlier, what kind and size of boat?
As for the carb looking "clean as a Whistle", what you see may be clean, but in the passages where you can't see...

 

[Chinewalker]

Agreed -3700 revs is way too low. You're lugging the engine - akin to driving uphill, in ever drive, while towing a heavy trailer. Sounds like you might need to downshift. Maybe an 11P?

 

[rabidhunter66]

16ft alumicraft side console. Home made plywood decks and trolling motor.

 

[jimmbo]

An 11" might still be a bit too much pitch, for that combo. On a much lighter(no console, no plywood decks) 14 ft , we used a 13

 

[rabidhunter66]

Ok, ill look for atleast an 11. In anycase it would be much better then the 15. Guessing id get it up to around 4500. But if i dont get it running consistantly well it wont matter. LOL

 

[PDean]

Likely a fuel /carb issue. May require carb removal and cleaning. I have a 35 and have done as much. It’s not what you see it’s what you don’t see. If you take it off check all the screws for tightness. Could be sucking air somewhere.

 

[rabidhunter66]

Carb is coming off Thursday morning and I have a bunch of seafoam ill soak it in overnight unless someone can suggest something else. Someone also said something about the reed valves. Ill see what I can see when I take the carb off. Im not getting any blow back at the carb that I can tell so Im hoping its just a piece of crap still in the carb.

 

[jimmbo]

Lacquer Thinner is what I've always used. Just don't put anything plastic into it. If you aren't getting any "blow back" then the Reeds are fine. They have a very long life expectancy and a very low failure rate. The originals anyway, those flimsy glass ones are a different story.