1978 35 Evinrude wont run at hispeed

[jentz]

I got this motor used,It wasnt pumping water so I looked at the impellar,It was new the water tube to the engine wasnt in its block hole.Next wouldnt Idle so I did a carb clean,Got it idleing fine.Today I but it on a boat test run,It idles and shifts just fine but giving it full throdle it only runs 1/3ed of full speed it just maxes out at way less than full speed.It doesnt sound like its running at hi RPMs.

I gave the water pump as a example I believe the previous owner did his own work and not the best mechanic.

New nonoxy fuel,carb cleaned, just not running right at full throddle?

I'm a fair mechanic,Outboards not much experience,could it be spark advance if so how to set it?? HELP

[marine_man]

I would run it on the hose at higher rpm and verify that all of your cylinders are firing first.

After that... I'd try and isolate if it's a carb problem or ignition related problem - pull the choke and see if it picks up or not at higher rpm's.

marine_man

[Eelpout08]

Does that motor have a throttle stop to keep it from over-revving in neutral? i would start by checking to see if the throttle blade at the carb is opening all the way, if that is working properly start checking the ignition, main carb jet, syncronization,etc.

[marine_man]

One other comment.. I presume when you cleaned the carb you bottomed out the needles and counted the number of turns to make sure they are adjusted the same way now?

marine_man

[jentz]

2 cylinder both firing fine,Shift neutral stop working also,Carb has factory set Hispeed No adjustments,low speed I have adjusted.

When I installed a elec.starter the old rope pull start had a mount with a full advance stop,The new starter mount has its own,I took a measurement of the old and set the new advance stop to the same measurement, not the legnth of screw but the distance from stop to cam.Could this be my problem the full advance stop? The work that was done by the old owner was poor. I am wondering if the sync could be off? or maybe me setting the advance stop wrong? The carb is opening all the way,just little power or speed and My ear tells me its not hitting its max 5500 rpms maybe 1/2 or less.

[cribbageboy]

Had the same problem on my 1971 40 horse Johnson. Turned out to be the high speed jet. I would double check. Sometimes those things can back themselves out. That would be my first guess. Easy enough to check too.

[jentz]

Thanks I brought it to Tiger out here, he looked and said sync is off.come in tomorrow and pick it up.That was yesterday