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Cracked oil sump on oilhead?

PIRATEJOHN

New member
My beloved R1100GS, a/k/a the Robomantis, suddenly dumped about 1.5 quarts of oil on the ground over the weekend. After taking the factory skid plate off I was somewhere between amazed and horrified to find a crack in the aluminum that makes a semi-circle around the mounting for the centerstand. :sick

Anyhow, I have never heard of one of these engines cracking like this. I don't recall hitting anything, although I guess that it's possible that I hit something in Mexico two years ago and it's just now coming to light, since the bike has mostly been in storage since then.

The engine runs and sounds great, so it's not like something internally came loose.

I am wondering if this thing can be spot welded to stop the crack from spreading, and then sealed up with something like JP Weld.

I kinda hate to scrap the engine out because at 90K miles it runs like a top. Too bad that it is now leaking like the Titanic after hitting that pesky iceberg.

Any thoughts?

--PirateJohn--
www.PirateJohn.com
 
Well I'd have to see it in order to provide any final advice.

Providing you can get to the crack...

If it were mine, I would remove the engine, flip it upside down (after draining fluids), open up the crack with a Dremel by grinding a V groove into it and then cleaning/degreasing the area to the upteenth degree and have a pro TIG weld it.
 
I think a major problem in fixing it will be the presence of oil. Which would complicate either something like JB weld or welding. So yeah the engine would have to come apart and be cleaned up. I dont see how you could repair it with the engine in the bike. And since the bike is so old and so many miles, it only makes sense to examine/rebuild it while its apart. If you just fixed the crack without rebuilding the engine, its only going to come apart again soon to do that. Thats not to to mention transmission/driveshaft/final drive work that either needs to be done now or soon will be. This is going to cost $$$$.
So you are at a fork in the road here. Either to disassemble and rebuild the entire bike because you love it so much, or you sell/part it out.
 
I should probably keep out of this, but have you considered an oil additive which could fill the crack? I know there are some available, but that it would depend on the size of the fissure.

$20 bucks, and if it doesnt work, go for the expensive plan-B

[And now back to those more knowledgeable]
 
I should probably keep out of this, but have you considered an oil additive which could fill the crack? I know there are some available, but that it would depend on the size of the fissure.

$20 bucks, and if it doesnt work, go for the expensive plan-B

[And now back to those more knowledgeable]



I can see an additive (or basically using thick oil) helping if the engine had the sort of oozing crack that was like a bad seal. Alas, this is pretty dramatic. I put three quarts in and about 2 quarts poured out before I had a chance to put my jacket on, take it off again, and drink a beer as I watched in amazement.
 
I would take it to a good welding shop and see what they think. I bet it can be done without disassembling it. If you have a oil field welding service they can probably do it while it's running. :)
-Ray
 
I can see an additive (or basically using thick oil) helping if the engine had the sort of oozing crack that was like a bad seal. Alas, this is pretty dramatic. I put three quarts in and about 2 quarts poured out before I had a chance to put my jacket on, take it off again, and drink a beer as I watched in amazement.

Humm... I didn't know it was anyhting like that...

What about Alumaloy (as seen on TV)?

"ALL YOU NEED IS A PROPANE TORCH!"

"NO FLUX NEEDED!"

"NO HIGH WELDING TEMPERATURES -- NO ARC WELDING!"

It looks "cool" on TV, and I have been tempted to try it for several repairs...but I never have.
 
I kinda hate to scrap the engine out because at 90K miles it runs like a top.

You don't have to scrap the motor but I'd feel pretty funny about trying to fix it in-situ. And once it comes out you might as well replace the case rather than repair it, so you know the sealing and alignment won't be messed up and you'll know that the mounting points are at original strength.

I have a decent silver case here from a '99, so it has the later venting system. What year is your motor? Replace the case, freshen up the bearings and top end...
 
I would never consider putting any kind of chemical or fluid in the oil that supposedly fills cracks. Something like that would almost have to cure in the presence of air, which is possible if you have a crack in the case. But, since any engine does breathe air, its possible the fluid may also cure in recesses or passageways inside the engine.


Perhaps if you were stranded somewhere in Patagonia I could see using it as a last ditch effort to get somewhere.
 
I would take it to a good welding shop and see what they think. I bet it can be done without disassembling it. If you have a oil field welding service they can probably do it while it's running. :)
-Ray

unless you got your own tig welder
tig002.jpg

i can weld it for you,no problem.can you take foto of the cracked case.use of any type epoxy is only temporary fix,things you do on the road so you can get home.
 
I've used alumaloy on aluminum coils in refrigerated cases in supermarkets. Wonderful stuff. I can guarantee that it won't work on this as you won't be able to get enough heat in it with a propane torch and the stuff absolutlely abhors oil.
 
The engine and cases are stressed members of the bike. Just sealing the crack without preparing the ends by perhaps drilling a small hole, might not do it long term, the crack could still propagate later.

Unless you are in Bangladesh and need a fix to get home, for amount of work involved I'd fix it the right way by replacing rather than patching - I wouldn't want to have to pull it apart for same thing again.

Just my 0.02.
 
Here's a photo:...
Was the bike shipped while on the centerstand, or moved with a forklift, or anything like that? The most likely scenario I can see is a whopping hit via the centerstand mounting, like it was on a pallet and got dropped to the ground hard, or MAYBE you took a bad hit to the c-stand offroad. I'd think htat the latter would have left a big mark on the stand.

A hit to the bashplate, at least the stock one, I think wouldn't do this because the rubber dampers would disintegrate l long before they could transfer that much force. Plus the bash plate fastens to a different area. Looks like it's the 'shelf' that got whacked, and that's where the c-stand is.

I have a cracked R11 case here from a guy who had his R11GS shipped by the Army. They put it on the sidestand and strapped it down hard enough to crack the case (it was probably shipping impacts which finally did the job). The Army bought him a new short block.
 
Was the bike shipped while on the centerstand, or moved with a forklift, or anything like that? The most likely scenario I can see is a whopping hit via the centerstand mounting, like it was on a pallet and got dropped to the ground hard, or MAYBE you took a bad hit to the c-stand offroad. I'd think htat the latter would have left a big mark on the stand.

A hit to the bashplate, at least the stock one, I think wouldn't do this because the rubber dampers would disintegrate l long before they could transfer that much force. Plus the bash plate fastens to a different area. Looks like it's the 'shelf' that got whacked, and that's where the c-stand is.

I have a cracked R11 case here from a guy who had his R11GS shipped by the Army. They put it on the sidestand and strapped it down hard enough to crack the case (it was probably shipping impacts which finally did the job). The Army bought him a new short block.


A year or so ago some poor guy backed into the bike and pushed it forward, causing the center stand to fold under the bike. At the time I didn't think much about that being the cause of the crack, but now I am wondering.

And as I indicated, I hit a few things in Mexico 2 years ago but didn't think any of them were that severe.

Otherwise the bike has been in storage mostly since that Mexican ride.

The last time that I can remember trailering that bike was in 1999. And the center stand was up and it was supported by straps only.

Frankly this is a bit of a mystery.
 
John,

Bummer, if it was my bike I would pull the engine and replace the sump.

I have done quite a bit of aluminum welding, and the material has to be real clean to get a good weld. It's just not worth chancing a leak later when good used sumps can be found.

my 2 cents
 
John,

Bummer, if it was my bike I would pull the engine and replace the sump.

I have done quite a bit of aluminum welding, and the material has to be real clean to get a good weld. It's just not worth chancing a leak later when good used sumps can be found.

my 2 cents


Thanks. I am inclined to try to get someone to at least spot weld it in place in order to prevent the spread of the crack, and then use JB Weld if necessary to stop the leak on the theory that if that doesn't work then I will rebuild or replace the entine engine in order to make this right. The bike's too good to simply part out.

If I do have to disassemble the bike and engine then I will certainly replace the part rather than taking the chance with a repair.

Someone suggested aluminum brazing today. Any thoughts as to whether that might work?
 
John,

You will not be able to weld the part (or braze it) without taking it off the bike and cleaning it. As you heat the part, oil that is in the metal seeps out and into the puddle (thats where the metal is molten). The oil contaminates the weld and causes small holes. It sucks but there is no other way.

I would be afraid that a temporary fix would fail at the most inappropriate time. Murphy's law. You could end up with oil on the back tire. This of course would be a disaster.

I once had a small oil leak develop on my Yamaha sport bike on the way to work. It spit me off so fast I couldn't believe it. luckily I was only going about 30 and had gear on.

I urge you to fix it right or park it until you can. It's just not worth loosing your life over.

Best wishes,
 
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