Half Speed - 1981 35hp Evinrude

[Coleengland24]

Hello, so I have a 1981 35hp Evinrude. It’s on a 16/48 Jon boat that has a deck on the front. Last year the motor seemed to only run half of the speed that it should. Right around 15-17 mph. Also at this time it was constantly spitting and sputtering while having a hard time idling.

This summer I have rebuilt the carburetor and added a new fuel pump, along with new fuel lines as well. Also has good plugs. The motor started up well and seemed to run without dying or sputtering. It idled what seemed to be good as well. But it is still only running half speed? At full throttle it still feels bogged down and acts like it’s not running all the way. Tonight we checked compression and it read roughly 120 on both cylinders and had a good spark on each, so it has fire.

I’m not sure what the next step should be. I had an old timer come by and look, he thinks there is something going on with the reeds internally, but wasn’t sure either. I’m hoping to get some other input without having to take it to a mechanic.

 

[oldboat1]

Remote throttle cable? Check it.

spitting and sputtering out of the front of the carbs could be reeds, but pretty uncommon. Do the usual battery of tests: compression, measure spark with an open air adjustable tester, check fuel condition in tank (water?), consider carb rebuild.

 

[NicoPags]

I do remember my 78' 35HP doing that as well. In my case was the throttle cable allowing WOT. To verify, I had removed the cable, put motor in a tank and throttled by hand. Trying to recall, I had messed with the crowned adjustment nut on the motor end of the cable to fix the issue

 

[DevinM]

If yours is like my 78’ 35HP Johnson check the leaf valves. I had same symptoms and I seen mine were broken after about the third time removing carb. Do you have an in-line fuel filter that may be clogged?