Serious Help Needed

[Guest]

Upper Front motor mount GS1100e, engine fresh from builder after bike was rear ended by pick up. The little rounded shelf you can see on lower right is part of upper case that projects out past lower case. Engine fired right up and is running strong but I immediately noticed oil on top side of the shelf.



Added baby powder to area after cleaning surfaces, then re-started engine.



Hair line crack highlighted by dissolving baby powder









In this picture you can see oil making way down lower case.

So what is it going to take to make this right and stop the leak?

Can hairline crack be welded? I have access to skilled aluminum welders.

Would cases need to be re-separated? Please say no......

Would weld have to go down face and around bottom of shelf?

[friedshrooms]

what if you put some of the sealer they use to seal the two halves together along the crack?

[almarconi]

I would disassemble the parts and have them inspected for cracks. A machine shop should be able to use a penetrating dye on the aluminum to see if cracks are present. Since bike was in an accident, the obvious crack may not be the only crack that is present. Once you identify the cracks, a competent welder should be able to repair them. If the oil is under pressure, its doubtful that a sealer would hold. Better to fix it properly than to do a half a**ed repair.

[Rick65Cat]

what if you put some of the sealer they use to seal the two halves together along the crack?

I split the cases on my '78 1000 back in '80. I used genuine Suzuki case sealer glue. It only works to seal when theres preasure on it. As in the bolts holding the cases together. Just injecting sealer probably won't work.
Aluminum welding is best.

[Spyderman]

rick check you PM

[TheCafeKid]

With the money already spent, I'd attempt to seal it with high temp silicone or something like that before splitting the cases again. If it works fantastic if not you have to split em anyway. I've heard tell from a couple of people now that know alot more about this stuff than most of us that silicone is used quite frequently to seal weeping welds or case cracks.
I think it was Blowerbike that was telling me not to long ago about how he had a motor brought to him in a box from a 1000g where the basket had let go and blown the side out of the case. He had the cases welded but once it warmed up he found that oil was actually weeping through the welds. He iirc seemed to think that the cases are simply to pourous to weld well and that it would like weep anyway. So he smeared a thin coat of silicone on it and it stopped it.

[blowerbike]

there is no pressure there.(crank slinging oil against case).
what josh(TCK) said would not be half ass.
this isn't a show bike is it?
listen to the post above mine and you should be fine.

[Nessism]

I would disassemble the parts and have them inspected for cracks. A machine shop should be able to use a penetrating dye on the aluminum to see if cracks are present. Since bike was in an accident, the obvious crack may not be the only crack that is present. Once you identify the cracks, a competent welder should be able to repair them. If the oil is under pressure, its doubtful that a sealer would hold. Better to fix it properly than to do a half a**ed repair.

You can see the crack now, no need for any special detection methods.

Bummer. I'd be crushed after putting all that money and effort into a rebuild only to recognize the cases are cracked. The sealer idea couldn't hurt to try, although I'd go for something like JB Weld myself.

[almarconi]

You can see the crack now, no need for any special detection methods.

Is that the only crack..Ed? Can you tell that just from looking at the picture?

[Guest]

Thanks for the initial suggestions. I did put some of the orange copper hi-temp silicone sealant on before those pics were taken and it did reduce the oil flow but it was still leaking, just less.

I was thinking about a small bead of JB weld, but don't want to start down that route till I can decide about whether a structural weld is required.

I don't have any good photos of the upper case with it split apart. I'd like to see up close up of what both sides look like. If you look at the second to last photo from the bottom side of the rounded shelf you can see the straight line crack continuing around. Is it suppose to look like that, or should that be one solid piece there with no crack between the shelf and the case portion that becomes the motor mount?

I guess the significant question here is will the crack get worse over time? If yes then I would think a structural weld would be called for. On the good side the engine is supported below by the lower mounts. I would assume that the torque from the drive line is going to be the big force on it. Can the cases be welded with oil in the engine and the engine still in place? I think it would be an easy weld on the top surface. My concern is how close could the welder could get on the bottom side without welding the cases together. If he doesn't get close enough would that final area still be a leak point?

The other good thing (so far) is that the oil seems to form along the hairline crack and travel down on the outside surface. I say so far because I haven't ridden it since getting it running. Just been doing short idle cycles in the garage.

The bike isn't a show bike but it is in pretty damn nice shape. Luckily the crack is in an area that's hard to see. As others have said I have a boat load invested in this engine now and even if it takes replacement cases I need to finish things. The cases aren't leaking from anywhere else.

Heartbroken is a good term for the way I'm feeling. This all started last Memorial Day
and I set an artificial deadline to be done by this Memorial Day. Met the deadline then had the "crack" crop up. Not to mention spending the last 7 days in the hospital fitting a bacterial infection that was blocking my breathing tubes. Man when it rains it pours. Unless your lucky like me and have a window seat in the hospital and miss 7 perfect days of early riding.

[bonanzadave]

The bike isn't a show bike

Thats pretty funny .

Heartbroken is a good term for the way I'm feeling.

Is the bolt in the pics a mount point ? If so Im not sure I like any kind of "glue" idea.

Keep yer chin up. Theres always next season and many more to follow. What would you do all winter if you didnt have a cool project like this.
Start looking for that case. A machine like that (and you too) deserves it !!

[drtybykr]

dress it a bit with a file, and JB weld it. If you have to go the weld route, the JB can be ground off. The case will need ground for proper weld penetration anyhow.

[Guest]

Well I talked to one of our world class aluminum welders here where I work and the answer was not good. I didn't have any of the pics to show him but He basically said if there is oil behind it and embedded in the crack he won't be able to get a good weld. He said it would look like crap if he could do it.

So I'd still like to hear from others builder/racers like Rapid Ray and Blower Bike concerning whether a structural weld is required from a stress point of view.

I'm starting to lean towards a replacement set of cases if I have to have split these cases again.

[Guest]

Thats pretty funny .

Is the bolt in the pics a mount point ? If so Im not sure I like any kind of "glue" idea.

Keep yer chin up. Theres always next season and many more to follow. What would you do all winter if you didnt have a cool project like this.
Start looking for that case. A machine like that (and you too) deserves it !!

Thanks Dave, That's the upper front motor mount bolt.

[TheCafeKid]

I know your upset brother. That would have me rather upset for certain. I'm not an expert or even close. Nothing more than a shadetree bike mechanic at best. But I would also be concerned like you about it being a stress point. Which motor mount is it? I couldn't really tell which or where in the pics. I do know from previous experience that even a lowly 750 has enough grunt to pick the motor up and try to turn it in the frame without the top front mount in there. By turn it I mean rotate it back toward the rear of the bike. I was in a fevered rush to test out my cafe and forgot the front mounts and it yanked on that sucker hard enough I had undo the rear mounts and use a Jack to get the motor repositioned. Having said all of that since you still have the rear mounts the bottom mounts and a solid side of the top mount I'd wonder if there would be anyproblem at all. If it's chain side that's the cracked mount if anything I'd wonder if it wouldn't actually close that weep up under power. Again I'm no expert.