Another upper crank bearing question....

[gregr1971]

1996 112 johnson. the upper bearing shows side to side slop, quite a bit, and growls while running. my question is: will the bearings fall out into the crank case when i remove the assembly?
and also, what keeps the crankshaft from being eat up when these get a lot of play in them???

 

[R.Johnson]

Re: Another upper crank bearing question....

You can remove the upper bearing housing assembly with tearing the engine down. A growling noise does'nt sound good, I would remove it, and take a look. Crankshaft damage is certainly possible if this bearing has failed. Why it failed is another question.

 

[F_R]

Re: Another upper crank bearing question....

Very unlikely that it failed alone. Expect other bad stuff. Yes, the crankshaft is the inner race of the bearing, so if the bearing is bad, so is the crank.

 

[gregr1971]

Re: Another upper crank bearing question....

here is the reason for failure. but how did water get in there?
will a 1979 115 powerhead fit on my mid section????

 

[Chinewalker]

Re: Another upper crank bearing question....

Could be as simple as condensation on an improperly stored/winterized motor. For the most part, the upper main gets the least amount of lubrication and a 50:1 mix doesn't leave enough of a film for long term storage. Condensation on bare metal can start rust spots.

Could also be the motor was sunk at one time and not dealt with immediately. Might have been started right off the bat, but not run long enough to dry things out inside sufficiently.

Could also have been a little water in the fuel, subsequently circulated into the upper main with the recirc hoses...

- Scott

 

[F_R]

Re: Another upper crank bearing question....

A leak in the exhaust cover area can squirt water into the exhaust ports. Then it finds it's way to the crankcase and it's good-by powerhead.

 

[gregr1971]

Re: Another upper crank bearing question....

how much vertical play should be in the crank? i lifted up on the flywheel, semmed to lift about 3/8"

 

[Chinewalker]

Re: Another upper crank bearing question....

Without the upper main in place, you'll get a fair bit of up/down play. The upper main keeps it from going up...
- Scott

 

[Dhadley]

Re: Another upper crank bearing question....

That's simply typical water injestion. You'll find that the motor is mounted too low or there's something on the transom that causes a spray up the midsection of the motor. From there the mist or spray gets pulled in under the cowl via the air intake under the carbs.

From there it gets pulled into the air silencer. Some, if not most, gets sucked thru the carb throats. Some will end up at the bottom of the air silencer. From there it goes into that small hose at the bottom & rear of the air silencer base. As it drains back into the intake it ends up in the reflow system. Then it gets pumped to the lower and top bearing.

Once you take the front half of the block off you'll see the water is on the top & bottom bearing. It may be in the top & bottom cylinder as well. As you look toward the center main there will be less and less water intrusion / damage. IE - there will be water in the top and bottom and less toward the center.

 

[gregr1971]

Re: Another upper crank bearing question....

this play is noticable while it is all together, in running condition.

Without the upper main in place, you'll get a fair bit of up/down play. The upper main keeps it from going up...
- Scott

 

[gregr1971]

Re: Another upper crank bearing question....

well, how hard is it to pull the powerhead?? i have a 1992 90hp that lifted a ring off #2 piston, i pulled the upper bearing off of it, and it is clean and smooth. will the cranks interchange??

 

[guy74]

Re: Another upper crank bearing question....

I just looked on the brp website the crank from a '92 90hp and a '96 112hp are the same part number. There is also a crank fron a '81 115 hp motor on ebay, the part number isn't the same as the 92 and 96 V4's but others on here might know more about it.
Goodluck,
Brian

 

[R.Johnson]

Re: Another upper crank bearing question....

I made a mistake in my answer! I said with tearing the power head down, I mean't without tearing it down. Sounds like you have a problem here.

 

[gregr1971]

Re: Another upper crank bearing question....

ok, i tore down my 90hp, got the crank on the bench, i plan on using this crank in my 112. should i replace all of the rod bearings? and the lower bearing?
Also, there are some metal "rings" on the crankshaft, do those go back in the crankcase any certain way? meaning where does the end gap need to be.