Help!, Omc Upper Bearing Failure.

[MrCougar]

Hi, One of my frriend has a problem with his 1996,OMC 200H.P.,V-6 (No Ficht), engine,that is mounted on an fishing boat.
One month ago, the OMC mechanic discovered that the Upper Crank Bearing was damaged. The bearing was discolored (Overheated?), to maybe, due to lubrication??.
The dealer suggested changed the Check-Valves at the crankcase & the Upper Bearing. All these was done!
Yesteday,the dealer started the engine, and Run Fine. But we discovered that,thru the transparent lubrication line from the bottom to the Upper check valve the flowing of the oil was poor.
My friend is affraid to have the same result!!!!.
I forgot to mention,that after the new bearing 6 Check-Valves was installed another tedt was performed, by the OMC mechanic, Injecting TCW-3 Oil thru the Circulation hose,that feed the Upper Bearing,using an medical syringe. The sound of the engine improve after the test.

Hei, Mr OMC GURUS!, How can this problem be solve???,to improve the longevity of the Upper Bearing???. Thanks & Happy New Year. DON

[H2OPERF]

How did he come about pulling the upper main out were all the bolts loose?The oil line from the bottom main to top is not going to flow oil like a waterline its basically leftover mixture that makes its way up there, it usually kinda bubbles out slowly.What do you mean by discolored ?brownish path at the rollers is not abnormal Is he using the vro oiler? my rule of thumb is if its out of warranty dont use the vro.If its a dark blue path not so good.Did they mic the crank? you said it sounded better with oil,A good bearing on a good crank shouldnt make any noise even almost dry.omc has the biggest upper main in the industry they havent had much trouble with it .

[racer]

First there is no check valve at the upper bearing just a 90 degree fitting. the line is not clear from the factory and should have a one way valve about 3 inches from the bottom fitting.The 6 valves must be recirc valves. The only time I have seen this problem was do to water injestion.

[dan agnew]

racer you must know it has been years since i went to omc school but i always thought that the oil was circulated by crankcase pressure on the bottom cylinder. the ones i have found with bad hoses pour oil out in little spurts. if so maybe you should for scuffed piston on bottom or bad lower seal that bleeds off crank pressure. or i could just be wrong!

Danny

[racer]

Dan,

Very possible, generally the lower seal will leak on to the top mount. Seal and crank ring good the bearing will build pressure forcing oil up. I have found bad one way valves and thus minimal oil to the top.

Al

[MrCougar]

Yes, and, how can Improve the lubrication of the Upper Bearing below 2,000 RPM , in those OMC V-6's Loopers???? DON

[Talon2.5]

ive been toying with an idea of making a manifold that the bleed lines from the cylinders would connect to and feed the bearing with those and at the same time remove the excess fuel that puddles at and idle, but i have to come up with the correct "holding" canister and one way check valve system with a pressure relief also

but havent gotten to it yet

[BenKeith]

Racer,

Is my 89 looper suppose to have these oneway valves? Skeet mention these, said they went inside the crankcase near where the check valves screw in. My motor doesn't have the critters. Is it suppose too?

Also, Talon 2.5 mentioned something I'm not fully understanding (that's a lot these days). I've heard others refer to the lines coming off the bottom of each cylinder refered to as bleed lines and used to scavange fuel as it puddles in the boost port during idle to keep it from loading up. Yet, the nipple that screws into the crankcase is a oneway check valve that only lets fuel go from the crankcase to the nipple in the bottom of the cylinder (provided it's good). The nipple in the cylinder is a #13 jet so I don't understand how it's used as a bleed line. Looks like it's for enrichment rather than bleed.

[racer]

Ben,

The valve I mentioned is connected to the hose from the lower to upper main. You are correct on the other six they take puddled fuel from the intake to the boost port so it is burnt.

[Talon2.5]

the ones up front by the intake are checkvalves the ones on the cylinders are 90 degree fittings that flow free

these are on a merc though, the ones up front by the intake you can pull through but cant push through, when ya put clear lines on them you can watch the pulsation in the lines and the fuel moving through them, i just gotta figure a way to pool it in the catch canister (homemade style manifold) and use the pulse to feed it to the upper bearing, may even use the stock fuel pump pulse hole thats capped off to push the fuel into the upper bearing line, it's kinda hard to put it in words, but ive got a half *ss idea in my head i just gotta find the time to start some sort of test piece