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1999 200HP OptiMax Disaster

R

rjg41

New member
"History: Engine compression

"History: Engine compression checked last year and found well over 10% variation in compression. Only 200 hours on the engine. Advised to have head rebuilt. There was carbonization and scoring. It was rebuilt. Due to time constraints could not use the boat since. Only used about 1 1/2 run hours. Last week the engine blew. Total disaster. Melt down of one cylinder. Had a warranty. Repair shop claims is was an injector that broke off and not their responsibility under the warranty. Yes, we are looking into a lawyer.

Questions:
1) Would inspection of the injectors during the rebuild shown the beginnings of failure or could it have failed so quickly?

2) Could the cyllinder have failed first and the pieces that came apart broken the injector? How likely is that?

Any other technical comments would be welcome.

Thanks."
 
Dick...What is the ser# of you

Dick...What is the ser# of your motor? Mercury had a bad batch of injectors a few years back. The proper injectors should be blue in colour or have a blue dot on them. When the motor was rebuilt it should of had the injectors replaced if not already upgraded. The problem was the center of the injectors was blowing out which if gone unnoticed could have caused a problem in the first place. Did an autherized dealer perform the work?
 
"Serial # is: OG899948

I am

"Serial # is: OG899948

I am aware of the injector problem. I had my original dealer and a friend at another dealer, check the Merc. site at the time. I was reported to be past the bad injectors independently by both. Did not note color or look for blue dot when I looked at the engine this week.

In this case the tip of the injector broke off not blew out which is what made me suspect that the injector did not break first but was broken by parts that let loose from the cylinder.

Yes, the work was done by an authorized repair shop."
 
"Dick...Do you know off hand i

"Dick...Do you know off hand if the oil pump prime was done, if not the powerhead wouldn't last very long due to lack of lubrication to the air compressor and block."
 
"Do not know about the oil pum

"Do not know about the oil pump. However, with the engine being run for over an hour after the rebuild at various rpm's I would suspect that with no oil, failure would have occured sooner. Also, there were no alarms before failure. In addition, only one cylinder shows any damage."
 
"Dick,

Do you know exactly

"Dick,

Do you know exactly what was done in the rebuild process? Was the block bored for oversized pistons?

Many shops will simply replace the rings and call it a rebuild. This usually ends in disaster.

Did the shop find the original problem that caused the bad compression readings before beginning the rebuild?

You said that the engine was not used for a long time after the rebuild. Was it properly prepared for a lay up?

Which cylinder burned?

Tony"
 
1) It is my understanding

1) It is my understanding the block was bored. I know block was sent out.
2) Was informed of no original cause.
3) Engine was typically stored for the summer. Used only in the winter in Florida. Fogged every year. Engine was fogged for the summer immediately after the rebuild per Merc. procedures for an Opti. Fogged directly into cylinders.
4) The cylinder that was melted was the lowest one on the left as you look at the rear of the enigne.
 
i have replaced many powerhead

i have replaced many powerheads from this problem they call it the pintal the tip that flies out of the air injector into the cylinder. new injectors are blue closest injector to cylinder head merc will replace injectors or free but will not pay labor if out of warranty i have hade many problems with optitrash i blew a brand new motor yes oil system primed merc sent me new powerhead it also blew merc said probable a problem with our powerhead I argued the fact i was shure i was doing something wrong checked everything merc sent another powerhead has been running for 2years koow explain that one
 
"Dick,

Since the cylinder w

"Dick,

Since the cylinder was melted, it would be my opinion that it was not caused by a broken injector. If the tip of the injector broke off it would cause damage, but I feel that the engine would have begun to run so poorly that it would have been obvious that something was drastically wrong long before the piston melted, if it melted at all. I have taken apart engines that had broken fragments inside many times. Generally there is damage to the piston top and head, and some scoring on the walls. Many of these engines ran for quite some time without burning a piston.

If the injector was malfunctioning, it could cause the piston to burn. That may have been the cause of the original problem. The shop should have checked out the fuel system thoroughly before assembling and starting the engine. That is standard procedure when rebuilding an engine. But again, if the injector was performing that poorly, it should have been obvious a long time before the piston melted.

A more likely scenario would be a poorly fitting piston, a leaking head gasket, an ignition problem (timing jump), cooling problem around the cylinder.

I may be wrong about these ideas, but in my opinion the shop should offer you some sort of compromise, even if they believe it was not their fault. When a customer spends thousands of dollars repairing an engine, the shop should take care of that customer.

This has not happened to me frequently; only a couple of times, but I did not hesitate to take the engines apart again and do another rebuild. I did not charge for labor, but did charge for any additional parts that were not replaced the first time, and I did not lose the customers. That is the way to handle this kind of situation.

Sometimes you just have to bite the bullet.

Tony"
 
"Dick,

There is one thing I

"Dick,

There is one thing I would add after thinking about this for a while. I realized that I had overlooked one important fact. The injectors on these engines are not in the combustion chambers, or anywhere near them. They are in the front of the engnine where the carbs would be on older motors. The oil mixes with the fuel before it is pumped through the rail and then to the injectors.

If an injector fails to operate at all, there is no fuel or oil for that cylinder, and that part of the crank/piston rod assembly. The connecting rod bearings and crank should have been damaged also if this occurred.

If the injector end broke off, the crankcase would have been flooded with fuel. I doubt the engine would have run long enough to melt a piston.

Of course this also means that a problem in the cylinder could not have caused the injector to break.

Tony"
 
injectors are on cylinder head

injectors are on cylinder heads there are 12 6 fuel 6 air they are stacked on top of each other via fuel rail fuel inj ok black air inj bad the new ones are blue this is a direct fuel injection engine tip off air injector goes directly in cylinder causing havic
 
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