Blown 88 Evinrude XP150

[jrpromax]

Last weekend a friend blow his XP150. Thankfully he shut it down the moment he started losing power. We pulled the heads and the top right piston had a light amount of aluminum splatter on half of the piston top. I know we are going to have to replace that piston and rings but do we have to do anything else to the other pistons and sleeves? Nothin got into the sleeve of the blown piston but I assume it still should be honed. Something else I noticed, this motor was rebuilt 2 years ago and the cross hatching looks like it is worn off the top and bottom of every cylinder. What should we make of that?

[Gordie Miller]

are keeping busy, yesterday your working on tractors, today it's outboards. I'm sure some of the gurus will be along shortly to answer your questions.

[B.Leonard]

Check the compression on the other cyls. If they're within spec, leave 'em. If that cyl isn't gouged, clean the aluminum off with muratic acid, scuff the cyl (break the glaze with a ball hone or similar hone), replace the piston and rings and run it.

Might want to find out why it let go in the first place :D

-BL

[jrpromax]

With new pistons and rings or the same pistons and rings?

[B.Leonard]

You could run the old rings and pistons. You might not even have to take them out (except the burned one of course).

You may want to at least re-ring the other holes in which case you would scuff those cyls with a glaze breaker also.

-BL

[Steve Reist]

That's funny Gordie. Someday Jesse and I will have time to work
on our own stuff or maybe go boatin' at my place on the
Mississippi. He has a Bass Tourney on my pool in Aug. As they
always say, It's a bitch being versatile! My river place is on pool
#19 above Burlington. Regards, Steve

[Forkin' Crazy]

You can do a compression check, but a leak down would be better. You can also check your piston to wall clearance and ring end gap just to make sure.

If you use muratic acid, make sure you clean it up very well. Better to do it outside. Fumes are very strong. Don't let it sit too long. It will corrode everything it gets close too. Best to keep it far away from anything in your shop or garage that is metal nad that you like. Lye will work too.

Have you found the cause....like a clogged up main jet?

[jrpromax]

It looks like bad gas was the main culprit. But I think there might of been an upgrade kit for this motor when they did the Regular gas to Unleaded switch. I think is consisted of thicker head gaskets and jets. So I am thinkin he never upgraded the motor and got a hold of some bad gas. But I need to find out what all is in the kit, I can only find a part number for the whole kit and not individual part numbers of what’s in the kit. Spark plugs indicate that it was on the lean side. All the isolators have white bases and a couple have white tops, which is way to lean on a bass motor. I suggested we ring and hone all six but he wants to get out of it as cheap as he can so I think we are going to only do the one cylinder. I told him we should go up three sizes on the main jets and to quit buying 87 octane and start buying 91. What do you guys think? Think I'm going to be doin this again in a month.

PS, Hey Steve, just put that basket of fish out infront of your dock and I'll get it the morning of the tournament. ;) Did you end up needing the intakes or are yours good?

[Forkin' Crazy]

What year is it? The thicker head gaskets were really used because so many people used the 87 octane fuel. In the early 80's they changed to a bigger combustion chamber. I would check the timing,clean the carbs, check the float levels, and check the fuel pressure when you get it back together. Only run it on fresh premium gas. Synthetic oil is a plus too.

I am running one to two sizes bigger on the jets with '80 heads and thin gaskets with 26 degrees timing. No problems so far. Give me the part number of the kit and I can run it down tomorrow and see if I can tell what's in it.