Front Left Cylinder Cases and Pipe loaded with Oil

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Mgmark
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Front Left Cylinder Cases and Pipe loaded with Oil

#1 Post by Mgmark » Sun May 26, 2019 10:54 am

Hello guys,
I bought an RD500LC a while back that needed crank seals. The bike was not running due to sitting for a number of years. Upon disassembly I found the engine cases for #2 cylinder (left front) had a few ounces of oil in it, and that exhaust pipe had even more oil than that in it. It’s my understanding a bad crank seal on that cylinder would suck air, not oil. Any ideas what it could be? I can’t tell if it is injector oil or gear box oil.

Thanks
Mark
1985 1GE RD500LC

steveho
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Re: Front Left Cylinder Cases and Pipe loaded with Oil

#2 Post by steveho » Sun May 26, 2019 11:22 am

Hi Mark,

If this bike is running the stock autolube oil pump, then the oil build up is likely due to one (or more) of the check valves not sealing. These are fitted on the outlets of the oil pump. This is relatively common and shows itself as oil in the crankcases after prolonged storage. A fix is to install inline check valves from a Yamaha outboard motor (marine). Search this forum for details. Rgds.

Mgmark
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Re: Front Left Cylinder Cases and Pipe loaded with Oil

#3 Post by Mgmark » Sun May 26, 2019 12:19 pm

Thanks for the reply. I’ve never had a problem with Yamaha check valves before. On my Suzukis and Kawasaki’s yes, but never a Yamaha. I’m replacing all of the oil injector lines anyway so I’ll look into th inline valves.

Mark
1985 1GE RD500LC

Luther
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Re: Front Left Cylinder Cases and Pipe loaded with Oil

#4 Post by Luther » Sun May 26, 2019 2:41 pm

Gearbox oil gets in from bad front right seal. Many get run till gearbox oil level drops on long rides. Left sides get loaded with fuel when leaning on sidestand too long. Use paddock stand. They all collect a lot of oil in lowerend if not rode like they should be after warmup. A large camp fire with lots of small fast burning wood is best way to clean pipes so you can moniter all cylinders spooge evenly in the future.

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pstamper
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Re: Front Left Cylinder Cases and Pipe loaded with Oil

#5 Post by pstamper » Sun May 26, 2019 2:42 pm

Yamaha 80 Horse outboard

Mgmark
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Re: Front Left Cylinder Cases and Pipe loaded with Oil

#6 Post by Mgmark » Mon Jun 03, 2019 4:25 pm

Now that I have the engine pulled apart I see there is a large puddle of oil in all four cylinders, down under the cranks. It appears a previous owner may have done this to store the bike as it was off road for a few years. I’m thinking #2 just got some extra and some made it down into the pipe. Of course I find this out after I buy a replacement pump to get some spare check valves that probably aren’t needed.
The crank seals are all smoked on this engine. It looks like they’ve had a torch taken to them. I’ve never seen crank seals this bad in any 2-stroke before.

Mark
1985 1GE RD500LC

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pstamper
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Re: Front Left Cylinder Cases and Pipe loaded with Oil

#7 Post by pstamper » Mon Jun 03, 2019 6:01 pm

Just the oil side? maybe water or something in the oil?

silverstrom
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Re: Front Left Cylinder Cases and Pipe loaded with Oil

#8 Post by silverstrom » Mon Jun 03, 2019 9:17 pm

Oil bypasses the mostly useless oil pump check valves and accumulates in the cylinders. It's very common and not at all unusual. All four will leak, but the left lean on the side stand makes those cylinders more obvious.

https://www.rzrd500.com/500phpBB3/viewt ... =3&t=14145

If your oil pump check valves aren't leaking now, they will at some point. These will solve the problem permanently.

Image

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