Problem with 85 Johnson 235

X

XtreemeChaos

Recruit
Joined
May 11, 2004
Messages
1
Hi, I'm pretty new to the boat world and am having a problem I can't figure out. I have an 85 Checkmate with a Johnson 235. When going full throttle, rpm's won't go over 2k. The boat acts like it wants to break over on plane, but seems to stop just before that point. While in neutral, the engine will rev up well beyond 2k and I have changed sparkplugs and replaced fuel filter and fuel line. I don't know what else to check. I'm pretty mechanically inclined, just not with outboard motors. Any suggestions?
 
O

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: Problem with 85 Johnson 235

Lets start by finding out the length and approx weight of boat.Next we need to know what dia and pitch prop is on the engine.Did this boat ever perform well with the current setup or is the engine new to the boat?
 
D

DJ

Guest
Re: Problem with 85 Johnson 235

XtreemeChaos,<br /><br />I think we can be relatively certain that your engine is not performing up to its potential. Unless you boat weighs 20,000 pounds.<br /><br />A 2 stroke engine will rev easily with no load (nuetral), even if all the cylinders are not working.<br /><br />With that said, we need to figure out which ones are NOT pulling their weight.<br /><br />Step one. a compression test. You need to do this with the ignition disabled, throttle wide open and a strong battery.<br /><br />All readings should be over 100 psi and within 5-10 psi of each other.<br /><br />Let us know what you find.
 
You must log in or register to reply here.
Top