leaking GS

[Guest]

Afternoon (it is here in Plymouth UK).

Having recently got my GS750 back up and running after 15 long years, I have an oil leak problem. If I'm just running around at low speeds (40-50mph max) then no problems / no leak. if I go over 65 then my left boot, the side stand and the left side of the rear tyre gets a nice coat of oil. It looks like it's leaking from underneath the starter motor housing, there is a drain hole under the starter and a corresponding hole on the opposite side next to the clutch pushrod. checked all of the oil seals and they're ok. Put a new o ring on the starter motor and that's fine.
Other than stripping the motor again (!!) I'm at a loss as to where the leak can be coming from and why.
Any advise gratefully received, don't want to spend the rest of the bike's life running around at 50mph.

 

[Brendan W]

Have you got a second hole in the starter well or on top of the crank case. Could it be a screw is missing ?
Could it be the oil filter. Starter drain is a bit far back and centre to get it on your boot I would have thought.
Is the breather free and clear ?

 

[Guest]

There is only the one hole in the starter well. The leak doesn't appear to be external in origin. Had the base gasket leak when I first got it running again so had to replace that and definitely no leaks there. Can't see that there are any screws missing (would be embarrassing as that's my job, selling screws!). I am going to check the crankcase breather is clear this weekend. If I can, I will try to take some pictures unless I magically spot the problem and sort it.

 

[Big T]

I there oil in the starter well?

 

[Boriqua]

This is a potentially stupid question but have you checked your oil level. Is it decreasing? I ask because afer getting my bike going a few months back I took it for a spin.... And man it started to smoke. Yup left shoe and rear wheel covered in something. I was freaking out!

Turns out it was to much chain lube and it threw off. It throws off right onto the crossover on the exhaust directly under the starter motor. I hit it with some degreaser and a hose and ... no more smoke ..wiped the chain some and .. no more wet shoe or glazed rear wheel ... Stupid damn amateur mistake from someone riding 35+ years.

 

[Guest]

There's no oil in the starter well, the oil level was just below the minimum level. It's definitely engine oil, it was still warm when I stopped and cleaned my boot and the frame rail. One possibility is that when the gasket leaked and covered most of my left leg in oil, what I'm seeing now is the last of that oil draining away. I will check the breather then take it for a spin, checking at 50, again at 60 and 70 to see if it leaks and at what speed.

 

[Big T]

There's not a trail of oil on the motor?

It can be any of the gaskets- valve cover, cam chain tensioner,or base gasket/oval ring

Degrease the motor, get a can of spray foot powder. Spray it on suspect parts of the motor, start it up and see if some oil appears in the powder

 

[Guest]

There is only the one hole in the starter well. The leak doesn't appear to be external in origin. Had the base gasket leak when I first got it running again so had to replace that and definitely no leaks there. Can't see that there are any screws missing (would be embarrassing as that's my job, selling screws!). I am going to check the crankcase breather is clear this weekend. If I can, I will try to take some pictures unless I magically spot the problem and sort it.

You're a gigolo ?

 

[Guest]

The amount of oil on my foot and the frame, it would have been apparent if it was from any of the engine gaskets. The oil is only underneath the engine but not on the sump. Checked the sump gasket / bolts and they're all ok. If the weather hold out this weekend I will give it a run and see what happens.

Thought I would fill you in on the latest regarding the oil leak. Was a two pronged attack by the bike to annoy me, re-torqued the cylinder head which stopped the oil dripping into the starter well. After cleaning the engine I went for a ride and took the side casing off...........to find the clutch pushrods seal leaking. Have ordered a new pushrods and seal so hopefully in the new year I should have a GS that doesn't leak oil.

Thanks to all that bothered reading and replying to my post. Hopefully I can repay the favour to another member in the future.

 

[AxelP]

The amount of oil on my foot and the frame, it would have been apparent if it was from any of the engine gaskets. The oil is only underneath the engine but not on the sump. Checked the sump gasket / bolts and they're all ok. If the weather hold out this weekend I will give it a run and see what happens.

Thought I would fill you in on the latest regarding the oil leak. Was a two pronged attack by the bike to annoy me, re-torqued the cylinder head which stopped the oil dripping into the starter well. After cleaning the engine I went for a ride and took the side casing off...........to find the clutch pushrods seal leaking. Have ordered a new pushrods and seal so hopefully in the new year I should have a GS that doesn't leak oil.

Thanks to all that bothered reading and replying to my post. Hopefully I can repay the favour to another member in the future.

I have exactly same problem. It is slowly leaking after 60-70mph, and all my left boot side stand etc...same things, I was thinking it is sprocket gasket but as you say it is clutch I will check on it too! Thanks for your thread!

 

[Guest]

Just putting out a thought here.

Assuming it's the same idea as my 850 there is a rubber bung in the engine cover for the stator wires that then feed through a hole to where the starter motor sits. If the rubber or the gasket have perished, this could be the source of your oil.

 

[Guest]

Thanks for the info, it's still leaking.....not as bad as previously. I might whip the cover off and check the bung. Once I get it insured again I can give it a run out and try the talc treatment to pinpoint the source of the oil.

Quick update. Stopped the leak by tightening everything that could be tightened. Found one of the starter clutch cover bolts was bottoming out so changed for a slightly shorter one and leak stopped.

On another issue, found out I had no compression at all on no. 1 cylinder (was previously low but not terminal) stripped everything out, valve guide on previously replaced head had been put in 0.007 out of line and inlet valve slightly bent.

Had a new guide fitted into a straight hole, bought new valve. Valve seats re-cut and valves ground in.

3/4 way through rebuilding engine so will update when I have it running again.