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Main Area => General GS500 Discussion => Topic started by: 1034am on July 23, 2016, 10:50:50 AM

Title: Oil leak from pulse generator
Post by: 1034am on July 23, 2016, 10:50:50 AM
Can anyone advise on the correct gasket or 'O' ring to fix oil coming into the pulse generator cavity? I'm getting a lot of oil in there. Thx.
Title: Re: Oil leak from pulse generator
Post by: 1034am on July 24, 2016, 03:39:30 AM
Anybody hear of an oil leak in the pulse-generator area? I can't seem to find any information on how its sealed from the crankcase.
The bike recently fell off the stand onto its right side, in case the might have knocked something loose (but what?)
Thanks!
Title: Re: Oil leak from pulse generator
Post by: sledge on July 24, 2016, 05:38:54 AM
Its a lip-seal, dims 22*40*8. Part no 09283-22015

Remove the sig-gen and coils and you will see it.

Drain oil, disconnect the oil pressure switch and remove the entire cover. You will then be able to knock the seal out. Lube the new one and carefully knock it in making sure its the correct way round. Suggest you replace the cover gasket when reassembling.


Title: Re: Oil leak from pulse generator
Post by: 1034am on July 24, 2016, 12:09:14 PM
Thank you x a million Sledge.
Been searching a lot for that info. Thx.
Title: Re: Oil leak from pulse generator
Post by: Shepa on July 24, 2016, 01:24:39 PM
If you tilt the bike enough to the left, and support it with a plank or something, there's no need for oil draining (if it's new and you don't want to waste it, for example).

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Title: Re: Oil leak from pulse generator
Post by: 1034am on July 24, 2016, 05:10:23 PM
Thx for the tip. An oil change will happen when I change the lower pan (also leakin')
Will probably go a little heavier on the oil, (20w-50) to try and keep it in the engine!
Title: Re: Oil leak from pulse generator
Post by: Shepa on July 25, 2016, 11:32:40 AM
15W-50 will do.
Mine was drinking almost half a liter of 10W-40 Silkolene between changes, and when I changed to Motorex 15W-50, not a single drop between change intervals.

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Title: Re: Oil leak from pulse generator
Post by: 1034am on July 30, 2016, 09:26:16 AM
Put the 20w-50 oil in & I'm still getting oil leaking, also out of the head gasket.
Does the head have to be resurfaced on a gasket job?
Thx.
Title: Re: Oil leak from pulse generator
Post by: Shepa on July 30, 2016, 10:42:42 AM
Are you sure it's the head gasket, and not the camshafts cover seal?

That one's usually prone to leak, and doesn't need any machining before seal change.



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Title: Re: Oil leak from pulse generator
Post by: 1034am on July 30, 2016, 05:20:50 PM
Well, it's leaking from the front of motor, next to a bolt that screws upward. I tried tightening it and must have warped or disturbed something, because before I tightened it was only damp/moist.
I'll inspect the cam cover seal and check for a breach.
Title: Re: Oil leak from pulse generator
Post by: 1034am on July 31, 2016, 04:48:46 AM
Can anyone advise: how to determine if a removed cylinder head requires resurfacing? Very certain that leak is from head gasket, now just trying to plan out the job. Not sure if a straight edge is needed or a special tool to determine flatness.
Also, will the lower cylinder body-to-crankcase gasket need to be replaced if head gasket is changed? (It is not currently leaking. Bike has 13,000 mi.)

Looks like my riding season is over for now. 🙁
Title: Re: Oil leak from pulse generator
Post by: W201028 on July 31, 2016, 04:57:04 PM
A straight edge and a set of feeler gages or shims is all you need to check flatness. I'm not sure the spec for the GS head, but most bikes Ive done are fine with .006" or so. Its been awhile since Ive done an air cooled, so it might be much more allowable, I truly dont remember.

Im sure the budda can chime in with the right spec.

Anyway, check it lots of different ways, i.e. corner to corner, end to end several places and in both directions, paying particular attention to the area where you see the leak. Remember it must be perfectly clean before checking, any gasket material left on will not show very flat.

If it is out by a couple thou, you can easily resurface it at home with some sandpaper or better yet emory cloth, provided you have a large, flat surface like a granite countertop. Ive also heard of using a piece of glass, but wood or metal is not acceptable due to their tendency to warp.

The way I was taught is large circles or figure eights with the head, while rotating it, not just a back and forth motion, but if your space is limited, it is what it is.

If you do have room, make sure you get sheets of sandpaper or emory that are large enough to do a figure eight pattern with the head. You might not find large sheets at the local hardware store.

If your space, time, or skills are limited, flattening a little head like the GS's should be a cheap job at any machine shop, and completed in a few minutes. If you are in the Harrisburg, PA area I would be happy to take care of it for you.

As far as the base gasket, I would pull the jugs. Its damn near impossible to clean the head gasket off without dropping little pieces into the cylinders or timing chain opening.
Title: Re: Oil leak from pulse generator
Post by: sledge on July 31, 2016, 10:24:35 PM
Torque down the headbolts before anything else  :thumb: