Oil leak at high speeds?

[Guest]

My 1983 Gs 1100e seems to lose a lot of oil when I'm going about 150 kmh?
I's from the lower part of the gear box on the left side or gear shift side. I replaced the O ring on the starter but that didn't work. Problem is that it only seems to leak at high speed and hard to pinpoint? Hoping someone may be able to give advise?

[Cipher]

Does this model not have a fairly high pressure oil pump?
If its actual seepage replace the seals where it appears to leak.

Sustained high speed hot running can evaporate volatile contaminants that have entered the oil maing it appear that your losing oil.

Hmmm
yes I once stopped after a sustained 2 hour run to find i had a low oil condition no case leaks at all it just disappeared. no smloking either. crank full of blow by juice.

[Fancool]

No it was all over my boot and rear tire but at "normal speeds" its dry and clean?

[Cipher]

stator cover wiring grommet ok?

[gsrick]

Possibly #30. http://www.partsoutlaw.com/oemparts/.../gear-shifting

[dorkburger]

Couple of thoughts... shift shaft seal? Output shaft seal? These would emanate from behind the sprocket cover. Is the crankcase vent at the top of the engine open / clear? If it's blocked it could pressurize the engine.

Hopefully it's not the crankcase halves leaking as mine do.

[Fancool]

Ok I will check that seal and I will give the results.
Thanks for the start.

[Fancool]

I did put two screens in the crankcase vent which runs to back of the bike and through a K+N Crank case vent. I hope using two screens will not cause too much resistance? I'll still check those seals.

[Cipher]

oh my that may well be the source of your problem
remove and test maybe?

[Fancool]

I will do that as well. I know ideally we should not travel at high speed but then they would not have made such a fast bike and we would all be riding scooters.

[Cipher]

blowby would increase at high rpms sustained high rpm running and a to resistant valving may be forcing oil out of the crankcase at the most poorly sealed joint.

[gsrick]

Just so you don't feel alone, both my 1000s don't leak until I get on the highway or I'm hauling butt like I stole it. Yes they are made to haul butt. Like with most engines the pressure rises with rpm(unless your pump is bad), the oil gets thinner as the temp rises and as mentioned will find the weak points in seals and gaskets. It sounds like you may at least have a leak that won't require tearing half the engine apart to fix.

[greg78gs750]

clean it and spray it with foot powder.

[gizzmo]

Could it be your using the wrong weight oil? I do know the older engines like mineral oil as well, after rebuilding a older engine for racing thought we would treat it to some modern semi synthetic, engine got up to temperature and leaked like a sieve put some castor gtx mineral oil no issues since which also helps as it's far cheaper

[bwringer]

I vote for crankcase venting as well.