Evinrude 150XP (1989)

[Eric Shelton]

So a buddy of mine is having problems with his motor. He is running a 1989 Evinrude XP 150 on a 1991 Shadow. The motor cranks and idles fine but then starts "cutting out" at high speeds, anything over 40. He took it to a mechanic who cleaned carbs and replaced fuel lines. He said the motor was running better, he only tested it with water hose. Buddy took the boat back out and it still does the same thing. He said he pulled the spark plugs and all but 1 had oil on them.1 plug still looked as clean as the day he bought it. Any ideas from the motor heads?

 

[Scott Hammer TOXIC]

Since we let Bob go on vacation, it will have to be a collective answer. 1 clean plug might mean he is not getting fire to that plug. I would check the plug wire since he seemed to have eliminated the fuel delivery system. More will chime in.



TOXIC

 

[Randy Janousek]

Since one plug was clean, I would say that it is not getting fuel. If it was receiving fuel, it would have some oil on it whether it was firing or not.

 

[TROY WAINRIGHT3]

Does this thing still have the vro pump hook up?If so im betting thats the problem.they have so many problems mechanics say the vro stands for very rarely operates.Sounds like the 1 cylinder isnt getting fuel or oil.When the plug ignites the fuel oil mix,that is usually what leaves the ignition marks on the plug.Good luck.

 

[Dan J.]

Not to be a Debbie Downer, but another cause of "clean plug syndrome" can be a head gasket leak or, and I hope not, a crack. Either will allow water into the cylinder and as it fires it pressurized steam cleans the plug and cylinder head almost like new. I'm not saying this is the case, but shooting in the dark I'd do a compression/leak down on the cylinders and check for any significant loss in that cylinder. A quick visual peek of the piston dome (remove spark plug and scope dome) can also let you know if this is the direction to follow. Good luck!

 

[Eric Shelton]

Well guys, bad news is the cylinder with one clean plug is getting water in it. We are gonna try and change head gaskets first and hope for the best. Thanks for all the tips!

 

[Scott Hammer TOXIC]

Sorry to hear and score one for Big Dan. This place is GREAT!!



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[Eric Shelton]

Yes sir, you were correct Dan. This site helps me more than you guys know, glad I joined...

 

[Eric Shelton]