PLEASE HELP!!671 tib problem

[35viking]

you guys are all making good points. Right now money is limited with not much work coming in so it has to wait to be fixed or checked for sure. What is a normal compression for those motors?

[Questsportfishing]

take some time to find out whats the matter before you add more problems to a list .. those engines should run for years without a mechanic. BUT they have told you the basic facts and thats if you let it go it can cost you way more and down time than you think. good luck

[JD5652]

you guys are all making good points. Right now money is limited with not much work coming in so it has to wait to be fixed or checked for sure. What is a normal compression for those motors?

"Normal" Compression = ~475 psi
"Minimum" Compression = 425 psi

You may get a couple schools of thought on this, but I prefer to take compression readings with the engine stone cold so as to detect any possible issue like stuck rings that may be masked with a hot compression check. When I say stone cold, I mean no block heaters or running for at least 12 hours.

[35viking]

The compression is right on the 425 mark and it was stone cold in the middle of like april.

[EnginesInc]

In my experience (and I'll be the first to admit I have yet to see everything), poor combustion as a result of a valve that is not seating does not improve over time. Whether the problem is as a result of a missing piece, or a bent valve, every time the engine runs with no load the cylinder temps drop to the point of producing white smoke. If the symptoms included little to no smoke at higher loads, but the smoke and raw fuel returned shortly after shifting to neutral, then a valve could be possible. Generally, valve problems do not last long in these engines before the valve either breaks (sometimes called "drops") or burns, as evidenced by a melted look along the face if any is left. Usually a valve problem will be accompanied by and audible ticking or hiss in the exhaust. Again, examination of the cylinder is possible through the airbox covers on the outboard side of the engine, and I would encourage you to do so.
Did you compression test all 6? What were the readings? Have you contacted the repairing shop with your concerns? If the original injectors are still in it, one mak be dripping at low speeds causing white smoke.

Larry Pecan
(No Phone)

[seapower]

May not hurt to "run the rack" again, couldn't hurt. A poor setting could be causing an excessive fuel issue.Frank

[JD5652]

. If the symptoms included little to no smoke at higher loads, but the smoke and raw fuel returned shortly after shifting to neutral, then a valve could be possible.

..... Usually a valve problem will be accompanied by and audible ticking or hiss in the exhaust....

These are the EXACT symptoms on the engine of the pictured head above.....Once the engine was disassembled the prognosis on the engine above was that it had less than another 100 hours before total failure.....

35Viking..... are you getting the picture??....these problems do not get better with time....they get worse ....up to and including catastrophically worse.....

If it were my boat, I would have a knowledgeable mechanic look at this engine before it is ran again......

[JD5652]

The compression is right on the 425 mark and it was stone cold in the middle of like april.

I'm assuming this was last April..... wonder what it is now almost a year later??

[35viking]

I'm assuming this was last April..... wonder what it is now almost a year later??

Yea JD it was last April during the survey to purchase the boat. Isnt it normal for those motors to smoke when the first start in the cold? Thats the only time it smokes now is at first start up. Once its warmed up there is no smoke at all its clean. There is also no fuel. It only happened that one time so what are the real chances of it happening again? It may have only been carbon build up or a clogged injector.

[JD5652]

Yea JD it was last April during the survey to purchase the boat. Isnt it normal for those motors to smoke when the first start in the cold? Thats the only time it smokes now is at first start up. Once its warmed up there is no smoke at all its clean. There is also no fuel. It only happened that one time so what are the real chances of it happening again? It may have only been carbon build up or a clogged injector.

My point of the above post was that it does not matter about the smoke, etc. If you had 425 psi last year, I would have the compression checked again..... it's not very costly and it will give you a good insight to the health of the engine. Also, as someone else mentioned, pulling the inspection covers are easy an really does not cost you much if anything.

IMO, things don't just fix themselves.... you may be sitting on a time bomb just waiting to explode....BE PROACTIVE!