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Burned Valves

L

leesoccer

New member
"1982 MerCruiser 120, Mech tel

"1982 MerCruiser 120, Mech tells me I have burned valves. Tuned up this year, requested tune up to run @ 3900rpm to 4300rpm as per specs. Mech put 11 pitch prop to get RPM. Ran OK but lost all speed. I put 19 pitch prop back on from last year. This prop ran great all last summer. Ran @ lower rpm. but more speed. When I put the 19 pitch back on this year. I could only get 2000 rpm. Returned to Mech, he informed me I now have burned valves. need HELP!"
 
"I now have burned valves.

"I now have burned valves."

Based on the age of the engine there are many worn internal parts besides the burned valves. I would install a remanufactured longblock or preferably a complete drop-in and play engine since many of the external parts on your engine are old and worn. JMHO
 
Lee A. Wetherby
Get a compres

Lee A. Wetherby
Get a compression test done on the engine and find out if the mechanic is right or not.
Bert
 
"I agree with compression test

"I agree with compression test. I plan on doing as soon as my buddy brings over a compression guage. As dropping in another engine, I only paid $1000 for the boat is it worth investing. I don,t need a money pit, Choices I have to make?"
 
"any boat, motorcycle, hotrod

"any boat, motorcycle, hotrod or house to me is a money pit, life is a money pit. If you dont feel the boat is worth a little money then sell it, if the boat is in good condition otherwise and you have a trailer, you may even get $1000 for it.

How much enjoyment did you get from the boat last year, what condition is the rest of the boat in?

If the engine repairs cost you 1500, are you going to find a better boat for that? and what repairs will it need? there's always something to fix or upgrade on a boat, for me that's one of the great things about them, I can personallize it like a hot rod.

If it was me, with no mechanic skills, I'd have a compression test done, then have the head removed to see if there is a problem with the head gasket, then while off I would have the head reconditioned, normally called a valve job and replacing or knurling of the valve guides.

But you may find the pistons and rings are worn, so though those things would help it can also put more strain on those week parts.

It's about the same money to get a long block or rebuild cylinder hone, pistons, rings, new rod and main bearings, valve job & gaskets with labor.

As Guy said due to the age of the engine it's best to get a drop in solution which can be found on the net, and I would think where you live it shouldn't be a hard find."
 
"Thanks Brian, You are 100% ri

"Thanks Brian, You are 100% right. The boats in great shape, it's up to me what I want to do. Compression test first. You can't make wise decisions without the correct information.
Thanks again
Lee"
 
Are you sure it`s got the corr

Are you sure it`s got the correct gear ratio?
A 14 x 19 should spin up with no problem.
Did it ever run correctly?
 
"Thats why a few of us are her

"Thats why a few of us are here I think is to help fellow boaters.

I hear ya about the repairs, I traded about 1000$ worth of computer stuff for my boat about 8 years ago and put about $2500-3500 into it and am not doing a transom (badly rotted) and a Cam swap, floor wood change and hopefully buying a new fuel tank and puttin in some new flotation foam. All about another $1000.. but I love the boat, how it rides, and looks (not just another Glass boat)

Wife doesn't like it, but my daughter does."
 
"Hey Guy's thanks for the

"Hey Guy's thanks for the advice. Found a place that will pull the head and have it sent out to be machined and rebuilt for a resonable price.It's a 17, Glassmaster in good condition. Was in a barn for 4 years. Seats, carpeting, canvas top are only 6 years old. I named her The Ellie'Ada after my grandaughters. I just had to make up mind what to do, hopefully I will be back on the Hudson by the 4th. Thanks again."
 
"Again, compression test resul

"Again, compression test results, verify you have the correct gear ratio in the drive.
pull the drive ,use a prop blade as a reference, mark the center section where the U joint is,and see how many turns it takes to rotate the prop one turn.
almost 2: 1.98
1 /1/2 : 1,50 V-8 ratio"
 
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