engine help

[jokerman808]

i have a rebuilt two stroke 115 evinrude. and i dont think it is running at its top speed. when i accelerate, it jumps up to its normal speed for maybe 3 seconds and then it slows down. i can barely get enough speed to pull a tube or get up on a plane. and sometimes out of no where when i am gunning it, it will get a burst of speed and then drop back down to its slow speed. and i know it can go faster because we've had it for a while and it was running great last year.

if anybody knows what i can do to fix this please tell me

 

[countvlad]

Re: engine help

i have a rebuilt two stroke 115 evinrude. and i dont think it is running at its top speed. when i accelerate, it jumps up to its normal speed for maybe 3 seconds and then it slows down. i can barely get enough speed to pull a tube or get up on a plane. and sometimes out of no where when i am gunning it, it will get a burst of speed and then drop back down to its slow speed. and i know it can go faster because we've had it for a while and it was running great last year.

if anybody knows what i can do to fix this please tell me

last time carbs were rebuild and a decarb done??? if none in the past year get it done...

http://forums.iboats.com/showthread.php?t=158076

what are the highest RPMS that you had the motor runing? current highest RPMS?

size of the boat and prop size?

 

[Chris1956]

Re: engine help

it sounds like a cylinder is running intermittently. See if you can figure out which one it is. Compare spark plug color. See if any are real black or oily.

If you can safely put a timing light on the motor, and run it and observe if you lose spark to any cylinder, that may rule out or convict your ign system.

 

[jokerman808]

Re: engine help

well we think there might be some water in the gas tank so tomorrow we are going to get the tank pumped and ill see if that does anything