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57 mercruiser wtuliped valves on intake

J

joe_p

New member
boat has 20.hr.running time ha

boat has 20.hr.running time has3 dead cylanders need help it has 3tulip valves intake
 
"Joseph,
A little more inform

"Joseph,
A little more information would be nice.

What do you mean by tulip valves intake? I have never heard this term before."
 
"What color are the tips on th

"What color are the tips on the spark plugs in the affected cylinders? You ran it very lean and/or overheated it. Check the timing, oil cooler, raw water pump impeller and make sure the circulating pump is good."
 
"Assuming the motor is injecte

"Assuming the motor is injected, has the coolant temperature sensor been checked yet? That would cause the fuel table to tell the ECM go lean. Time to run diagnostics and see if the ECM has an overheat stored. BTW, the overheat would be stored for ~300 key ON cycles and can't be manually erased from the ECM because it's stored in non-volatile memory. If the Merc diagnostic software is anything like what is used for outboards, it's going to show the max/min temperatures, max RPM and for how long, over-revs, etc. It's getting hard to do things and not have proof, somewhere. I'm not placing any blame but the previous owner (if there is one) may have caused this. Could be just a bad motor, too. Water in the gas won't make it go lean but a weak fuel pump/regulator/vacuum line/injector could. There are a lot of possible causes and I'm not sure taking it to a good dealer/service shop is a bad idea.

How long have you owned this boat, who does the service, what model year is it, and what else can you tell us? I don't see much info to go by."
 
"I see, So the valves are mush

"I see, So the valves are mushroomed in other words.
This does not happen much these days on new or rebuild engines in a 20 hour time frame.

The engine would have to have been making a pinging noise that would be easy to hear if it was running lean enough to cause this damage that fast.

Have you removed the heads yet and if so what do the pistons look like?

To take a guess I'd say that the valves were either not adjusted correct,were not seated correct or there was a vacuum leak at the intake on those cylinders.
But even if any of these things were not correct I still can't see how the valves could be damaged that quick.

If it were a case of bad fuel the other valves should show signs of damage as well and fuel doesn't sit long enough these days to go bad. That is unless it was in the boat for a long time like over a year. I doubt the boat holds 20 hours worth of fuel and if it did that much fuel should not go bad in one year.

Time to take it apart and see just what damage is done. A good automotive machine shop should be able to tell what happened from looking at the parts.

Good luck."
 
"Josh,

Jim is correct, tuli

"Josh,

Jim is correct, tuliping of intake valves is commonly caused by running hard during a lean condition. The lean condition, or lack of adequate fuel being delivered to the combustion chamber, causes the cylinder to run very hot. Fuel helps cool the valves and without this fuel the valves build up extreme amounts of heat. This heat, in combination with the extreme pressure in the cylinder causes the condition you are experiencing.

It is more common on carbuerated engines as EFI systems have safeguards built in which prevent this in most cases.

After repairing the engine have the fuel system checked out. Take a look at the intake gaskets to be sure they were sealing properly. An air leak effects the fuel mixture just the same way not enough fuel, and creates the same condition.

Good luck
Rick"
 
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