Cracks in case! What can I do?

[lisnup65]

I have a 86 250R motor that runs good and strong, but its been leaking oil on me. The motor is new to me and was redone by someone else less than 4 hours of run time ago. They did repaint the motor when they went through it so I did not see their was damage. I thought the oil leak was due to a stripped drain plug as is the case with so many that I have seen in the past.

Well I rethreaded the drain plug and installed a Fram sure drain to make sure the plug thread will remain in tack. I then put about 10 minutes of ride time on the machine to heat the oil a bit. I parked it for the night and the next morning I did not have the small puddle under it, so I thought the leak was solved. A few days later I then noticed some oil build up in the motor skid plate again!
I then flipped it back up and studied the case halves. Under layers of paint I found a crack on each halve. At 1 point the motor must of broke a rod or it was over tightened to hell on reassembly.

So what can I do besides part the motor of buy new halves. Is their a way I could make a repair?

[chris200x]

Oh man...I thought I had problems. You could try JB weld that should hold her for about 12 minutes. Probably gonna have to replace them.

[hrc85250r]

if thats all there is for cracks, pull the motor apart and have the crack TIG welded and have the little edge "surface ground" so its flat, it doesnt look like those are any load bearing parts of the cases, so its no big deal to get them welded up...if you take your time with the welding and grinding you could take dremel or something to the outside surface of the halves and they would look factpry with a good paint job....

[chris200x]

On that one picture I think I see many smaller cracks Like it's starting to spider or fracture. Cast aluminum is not the strongest metal in the world and it breaks very easily. I can't really tell though. If that is indeed the case I would replace them.

[lisnup65]

if thats all there is for cracks, pull the motor apart and have the crack TIG welded and have the little edge "surface ground" so its flat, it doesnt look like those are any load bearing parts of the cases, so its no big deal to get them welded up...if you take your time with the welding and grinding you could take dremel or something to the outside surface of the halves and they would look factpry with a good paint job....

That is what I was thinking. When I do get her apart I will know of what damage is done on the interior.

[max]

you cant weld it cause it has magnesium in it. i put some jb weld on mine. that stuff worked wonders. i got the jb stick. make sure your in room temp. apply the stuff on and let it cure for a few hours. the just sand it to where you want it the paint it. try this out before your go spending 1000 dollars to fix this. the jb is only about 5 dollars. good luck budy
max

[lisnup65]

On that one picture I think I see many smaller cracks Like it's starting to spider or fracture. Cast aluminum is not the strongest metal in the world and it breaks very easily. I can't really tell though. If that is indeed the case I would replace them.

It appears its only the 2 larger ones. The dark picture shows them the best. The oher stuff you are seeing is mostly the paint and the poor job I did removing it with my scotchbrite pad. I really does not seem to be weak or spider cracking.
I just cannot tell at this point if the damage was from the inside or over torque on reassembly.

[Billy Golightly]

Eh...temporary fix? get some real course sand paper (like 80 grit) and work on it, and go over with acetone, and then JB weld it.

The best fix is to pull the motor, split the cases, and have the cracks TIG welded. You can weld the cases but is pretty dang tedious work.

[x.system]

That looks like a skirt break to me. When they break and get lodged in the crank area thats usually what happens to the case halves. If it was from torque it would be around the bolt holes. They are repairable, I've had a couple done before and they hold fine. Just make sure you have the surface ground like HRC said. Good time to check out the tranny to while you have it apart. I would also look for more cracks internaly in the crank journal, I bet theres more. The last set I had done had about 3 cracks in each case half.

Hit up HondaATC, hes got the tools and know how to repair those.

[x.system]

Eh...temporary fix? get some real course sand paper (like 80 grit) and work on it, and go over with acetone, and then JB weld it.

The best fix is to pull the motor, split the cases, and have the cracks TIG welded. You can weld the cases but is pretty dang tedious work.

Hows that case half coming? Wheres the finished product? Pics?

[Billy Golightly]

lol x.system I did a little bit on your case, but I wanted to get an output shaft to put in both cases so I could make sure that the broke out peice was welded in straight and square with everything else. While welding up a sidecase I ran into a problem with the arc not being clean and I haven't fixed that so I haven't did much else on them. It seemed to start right after I did some steel welding. I'm not sure whether something is screwed up on the welder or what. I've changed the tungsten and it still does it. Its real erratic, its weird. Hopefully I can get it figured out and get back to work on them.

[sblt500r]

lol x.system I did a little bit on your case, but I wanted to get an output shaft to put in both cases so I could make sure that the broke out peice was welded in straight and square with everything else. While welding up a sidecase I ran into a problem with the arc not being clean and I haven't fixed that so I haven't did much else on them. It seemed to start right after I did some steel welding. I'm not sure whether something is screwed up on the welder or what. I've changed the tungsten and it still does it. Its real erratic, its weird. Hopefully I can get it figured out and get back to work on them.

i'm new hear and was looking through some of these and saw this. i have tig welder and do alot of case fixes. what kind of welder do you have? is it on the ac setting? are you stepping on the pedal enough? you need alot of power to weld aluminum right.
shawn

[x.system]

i'm new hear and was looking through some of these and saw this. i have tig welder and do alot of case fixes. what kind of welder do you have? is it on the ac setting? are you stepping on the pedal enough? you need alot of power to weld aluminum right.
shawn

How hard is it to learn how to weld aluminum? I have an aluminum welder available I want to learn on.

[Billy Golightly]

i'm new hear and was looking through some of these and saw this. i have tig welder and do alot of case fixes. what kind of welder do you have? is it on the ac setting? are you stepping on the pedal enough? you need alot of power to weld aluminum right.
shawn

Its a miller dialarc 300amp. It is on AC, high frequency. And yup, the pedal is open enough, to burn a hole if your not careful Whats happening is arc isn't like even. Its like making arc in some places and not others, and then it gets black and makes these little holes and ****. Its weird. My dad keeps saying its not clean, and he may be right but how much cleaner can you get then using a 40 grit flap disk on the pnuematic die grinder?

[hrc85250r]

you cant weld it cause it has magnesium in it. i put some jb weld on mine. that stuff worked wonders. i got the jb stick. make sure your in room temp. apply the stuff on and let it cure for a few hours. the just sand it to where you want it the paint it. try this out before your go spending 1000 dollars to fix this. the jb is only about 5 dollars. good luck budy
max

uhhhh, im 100% sure there is no magnesium in the R's cases, even if it did you can go to a professional welding place and they can do it, it just has to be welded in a vaccuum chamber... i would never J
B cases, it is the most horrific thing you can do, and i doubt if there is any internal damage....just bring it to a welding shop have it TIG'ed and be done with it, no problem....