'97 115 won't idle and spits all of a sudden

[bob johnson]

Re: '97 115 won't idle and spits all of a sudden

Do you think all that carbon was caused by just years of not being decarbed maybe? Does that look like a lot of carbon? I'm not experienced enough to know if that's a lot or a little, I was told it was a lot.

I thought anything lower than 5500 WOT was lugging it, but I guess 5200 probably wasn't enough to cause that much carbon.

Do any of you experts think that head can be salvaged, or should I expect to need a new head? Also why aren't the inside of the heads/combustion chambers full of carbon? I figured they'd carbon up too, but they look clean as new.

Thanks.

you should be able to find a head for $25 or so...

you dont want a hot spot.

you could file the high spots down and make sure you absolutely get all the steel pieces out of the aluminum!!!!!!!!!

but for the price of a used head...id just get another...

dont know if carbon was your culprit...


when the piston comes out, you might have more clues...you can look in the ring grooves and see if it is loaded with carbon.

I have a 1997 90 hp but it is a 60 degre V4...and the amount of carbon =gunk in the exhaust housing blew me away...almost totally choked off two passages..

bob

 

[MakoNY]

Re: '97 115 won't idle and spits all of a sudden

Any of the rebuild experts know if this looks like a lot of carbon, and what probably caused this much build up.

Never had an engine apart before, so I don't know if this seems like a lot of carbon build up.

 

[MakoNY]

Re: '97 115 won't idle and spits all of a sudden

Well I'm back on the water, finally got my new powerhead back and put on.

Anyway it's back and running great. They said I need to break it in at 25:1 for 20 hours and vary the RPM.

Just wondering if anybody can give me an accurate OMC break in procedure. I have seen things that say don't go over 3500 for 5 hours, don't go WOT until 10 hours and then in short bursts.

But the shop that put the powerhead on just said to keep it at 25:1 for 20 hours and vary RPM, not to stay under a certain RPM for a certain amount of hours or anything.

Thanks.

 

[ezeke]

Re: '97 115 won't idle and spits all of a sudden

Well I'm back on the water, finally got my new powerhead back and put on.

Anyway it's back and running great. They said I need to break it in at 25:1 for 20 hours and vary the RPM.

Just wondering if anybody can give me an accurate OMC break in procedure. I have seen things that say don't go over 3500 for 5 hours, don't go WOT until 10 hours and then in short bursts.

But the shop that put the powerhead on just said to keep it at 25:1 for 20 hours and vary RPM, not to stay under a certain RPM for a certain amount of hours or anything.

Thanks.

Click the thumbnail for a crossflow break-in from the factory manual.