Wormdrowner Posted June 20, 2009 Share Posted June 20, 2009 Purchased a 16' Sylvan with a 1992 Evinrude 90hp. Since buying the boat I have an intermittant problem with it losing power. Sometimes it runs fantastic, 40mph and 4800rpm, when it loses power it runs around 2200rpm. It idles and troll fine. I know this sounds strange, but when I go over another boats wake that will sometimes trigger the problem. Changed plugs and wires, ran great for two trips and now it's doing the same thing again. What I've done so far is: plus and wires, drained built in gas tank, changed fuel filter, carbs rebuilt, used different gas tank and hose thinking there might be something in the tank. Compression is 125lbs in all four cylinders. last night tried tapping on the CDI box to see if that did anything, it didn't. Would a CDI box cause this problem? I hate to keep throwing money at things when I don't know what causing this. Any help would be greatly appreciated. Quote Link to comment Share on other sites More sharing options...
Eric Wettschreck Posted June 20, 2009 Share Posted June 20, 2009 It's interesting that you say it happens mostly when you hit a wake. That would tell me that something may be loose....maybe. Or, a carb float could be sticking. Just thinking out loud here. Have you checked all your electrical connections to make sure they are not corroded and snug? Quote Link to comment Share on other sites More sharing options...
Wormdrowner Posted June 20, 2009 Author Share Posted June 20, 2009 Checked all electrical connections, rebuilt carbs although they looked extremely clean. Took it to a certified marine mechanic that lives near a lake, went over our own wake numerous times but of course it wouldn't happen with him in the boat. Quote Link to comment Share on other sites More sharing options...
marine_man Posted June 21, 2009 Share Posted June 21, 2009 When it drops off, is it for an extended period? I'd be tempted to take a timing light with and when it does it, see what the ignition system is doing.marine_man Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now ↓↓↓ or ask your question and then register. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.