XP150 noise

[ron755]

I have a 1990 XP150 Evinrude, runs good, but when going from full throttle to mid throttle, it sounds like a old hot rod when you take off in first gear, and let off the gas. One boat mechanic told me that the cross-flow engines made that sound. Has anybody ever heard of that? Or does anybody know what it might be. Only had boat out twice.

 

[emdsapmgr]

Re: XP150 noise

You can get odd sounds from an engine which has carbon around the piston rings, causing them to stick. When you let off, for some reason-you can get an unusual (abnormal) sound. The puffing sound may be caused by compression/exhaust gases escaping around the rings-not a normal condition. If you want to investigate, pull the side (bypass) covers off and check for carbon around the rings. If you see carbon accumulation around the ringsets and/or the piston skirt, you need to decarb the engine. Also check for piston scuffing, or aluminum transfer from the piston to the cyl liner. Is the engine hard to start when cold?

 

[ron755]

Re: XP150 noise

Engine starts OK. Is removing the side cover a difficult job?

 

[emdsapmgr]

Re: XP150 noise

4 bolts takes each cover off. Some have other engine-related parts mounted on top of them which-will have to be removed. You will need some gasket sealer and may need to replace the 6 side cover gaskets-not expensive.

 

[ron755]

Re: XP150 noise

Thanks for the imfo. I'll check for carbon this weekend.