1991 200 gt ?

[lily'sbee]

I'm away from home with work so I don't have Serial # and so forth but here is my question.
Motor was running great at about 5800 RPM. I wanted more H2O pressure so I replaced the pump. I also decarbed and put new plugs in. Well first time back out it started better than it ever has and ran like normal half the day. Then there was a shut down at WOT. The motor did not die but it lost so much power it was like I hit something. The prop and lu did not show any sign of impact. Ran the rest of the day at around 5600 RPM WOT. Motor still starts fine and idles as good as it ever has. Have had the BOOM 2 more times since then but motor never dies and runs just fine when I get back underway. I'm only getting 5350 RPM now and have lost about 4 MPH. Ideas?

[ChampioNman]

Check compression and get back to us.

[Tom G.]

Possible lean out on #2? I'm learning, too....

[ZeroHour]

Stuck ring after decarb....

Check compression and possibly run some marvel mystery in the cylinders.

Mine ended up being a stuck ring that freed up exact symptoms your expressing.

[THE WITCHDOCTOR]

Don't sound good... I am betting it ate a piston.....

[89basscat]

im experiencing something similar also.. after i did the decarb this spring. if a ring is stuck whats going to unstick it?

Jim

[ChampioNman]

$1,600.00 , Just Kidding Jim.

[THE WITCHDOCTOR]

That was bad Fred!!!!!!!!!!! Unfortunatly, he speaks the truth!

[lily'sbee]

Fantastic. Why would a decarb cause this? assuming that is the problem. What other symptoms might I have seen?

[THE WITCHDOCTOR]

Has it been decarbed regular? I had a bud with the same motor and his did the same thing when he did it, and his had never had it done before...

[pappastratos]

I wonder if decarbing big motors is not a good thing ??

[ZeroHour]

I think it has more to do with freeing up chunks of carbon that causes it. Regular decarb should not be a problem. I would almost in my opinion reccomend a series of mini tank treatments before a major shock treatment on a motor that had not been done recently.

In my mind anyway this would help reduce the size what may come free and cause less harm to the cylinder walls.

However I am somewhat new to this and may be completely off my rocker here...

[Bassmeister]

Fred has always advocated using some type of carbon cleaner in the fuel a few tanks before a decarb on engines that haven't been decarbed in a long time!

[lily'sbee]

Not saying that this is not the problem. I did start off slow like I read on here. I added a can of SEA FOAM with the first 30 Gal I ran. Then another can with the next 30 GAL, and another to the next 20 GAL. I ran 30 GAL with no treatment then did the decarb. I got lots of smelly smoke and a little black stuff, but nothing like I had read about on here. I don't know if it had ever been done before. I got the boat and motor in march. I sure thank all of you for your input. I'll keep you posted.