Oil pressure inside crankcase / JB Weld

3454 Views 45 Replies 13 Participants Last post by Nicad, 3 mo ago

Centexhunter

Discussion Starter · 3 mo ago

Newer Wee owner here and was wondering what the pressure inside the oil crankcase would be under normal load. My reason for asking?? I acquired a previosly owned 2014 650 and didn't notice until I was home the next day that the lower crankcase, on the right side where some skidplates attach, had JB weld there. I'm assuming it is a repair of a minor crack, as there is not a large area of JB weld. I seem to have a drop of oil on the garage floor about once a week and I have verified that it is coming from the repair area. I have put over 1500 miles on the bike with no problems...the longest continuous run was a full tank of gas to test my range.

So for all you seasoned Strom owners...if I were to do an extended ride for many hours, stopping for fuel/break only, would you be concerned? Is there enough pressure/heat over time to cause problems? To be hones, I"ve never used JB weld before, so I don't know how it holds up. Any advice/comments appreciated.

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hillsy

· #2 · 3 mo ago

Inside the crankcase there is minimal pressure. There is a breather to goes to the airbox hence the crankcase essentially breathes to the atmosphere.

A drop of two of oil is not a major concern IMO. Oil on concrete looks a lot worse than it actually is. But ultimately you will want to get if fixed for peace of mind.

Reactions: 3

Centexhunter

Discussion Starter · #3 · 3 mo ago

hillsy said:
Inside the crankcase there is minimal pressure. There is a breather to goes to the airbox hence the crankcase essentially breathes to the atmosphere.

A drop of two of oil is not a major concern IMO. Oil on concrete looks a lot worse than it actually is. But ultimately you will want to get if fixed for peace of mind.

Thanks for the reply. This makes me feel a little better! Yes, plan to have it fixed properly but am glad to know everything "should" be fine for now.

locoblanco

· #4 · 3 mo ago

JB weld works well, but you have to follow the directions precisely. I once repaired a small leak in a gas tank on a car and it held for many years. (After sold to a neighbor it still never had a problem that I heard about.) Perhaps you can drain the oil, sand the old JB a bit and re-do the repair better.

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hillsy

· #5 · 3 mo ago

Just re-reading your post - it's probably more than likely the gasket on the clutch cover is just weeping a little. The brackets for the bash plate mount to the bottom bolts of the side covers and it's possible the gasket got disturbed when the brackets were put on. PO might have just tried to JB weld as a quick fix. Would be pretty hard to get the JB to work properly in this scenario as it would be almost impossible to get the area completely free of oil.

Pics would help if you can post some.

Reactions: 1

Centexhunter

Discussion Starter · #6 · 3 mo ago

Thanks. I’ll try to update tomorrow when I can get better light for a picture. And my apologies if I got right/left side confused. The repair is on the brake side of the crankcase

jettawreck

· #7 · 3 mo ago

Centexhunter said:
Thanks. I’ll try to update tomorrow when I can get better light for a picture. And my apologies if I got right/left side confused. The repair is on the brake side of the crankcase

Brake pedal side would be the right hand side.
JB Weld properly mixed/applied to a properly prepared surface works very well. I repaired the cracked cast iron exhaust manifolds on my dad's V6 MerCruiser boat engine following a winter storage where the water in the manifolds froze (improper winterization service). They never cracked or leaked again thru several years use.
Inspect the repair area carefully. If just a crack a failure probably would be an inconvenience at most. If a piece was broken out and patched in a failure could quickly be catastrophic.

ratbikerandy

· #8 · 3 mo ago

I ran a carburetor with a JB Weld repair submerged in gas for 9 years with no issues. I think you will be fine.

Reactions: 1

Centexhunter

Discussion Starter · #9 · 3 mo ago

I think a re-work of the JB weld is in order because it appears to be just thrown on there?? Anyway here are some pics

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Centexhunter

Discussion Starter · #10 · 3 mo ago

Automotive tire Automotive lighting Fixture Grey Motor vehicle

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D.T.

· #11 · 3 mo ago

Wow, that's not a nice surprise.

Reactions: 1

RCinNC

· #12 · 3 mo ago

It wouldn't surprise me if that's been leaking ever since the original repair. It seems a little dark for properly mixed JB Weld, but that could just be the lighting.

I've used a lot of JB Weld over the years in my projects, and it's awesome, but it has some limitations. One of them is that, in its uncured state, it doesn't like petroleum products, so the repair surface has to be really clean. Since this is a crankcase, even after most of the oil leaked out, it can still drip for what seems like forever. If the crankcase was still dripping a little after he made the repair, it could have weakened the bond between the JB Weld and the aluminum. Other than cosmetically, i wouldn't have any issues with a JB Weld repair on a crankcase, and it's a lot cheaper than having someone TIG weld the crack. If I planned on re-doing the repair, I'd grind off as much of the old JB Weld as I could with a Dremel or some other kind of die grinder, and I'd lean the bike against something (like a garage wall) that would tilt it away from the side with the crack in it. Gravity should then help to keep oil from collecting at the crack while the JB Weld cures. Rough up the surface with sandpaper or a wire brush, clean the surface really well (JB Weld recommends acetone or laquer thinner, but no alcohol or cleaners that leave a petroleum residue), and reapply the JB Weld.

I'd probably change my oil once the repair had cured. If you're going to be grinding off the old stuff, and there's any chance that bits of ground off material got inside the crankcase through the crack, I'd want to get as much of it out as I could.

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Wee van Cleef

· #13 · 3 mo ago

I'd remove all the old epoxy with epoxy remover. You can probably get it all with several applications. Quite a bit of work, but then you can assess the original damage.

A master JB welder can put humpty dumpty back together again.

Drain the crankcase. Tilt the bike so no motor oil can seep into the crack. Scrub the area thoroughly with acetone and a soft brass brush. Apply the epoxy with a popsicle stick or whatever. About 2 hours after, you can smooth the epoxy with a wet finger and make it look pro.

jettawreck

· #14 · 3 mo ago

Yeah, that's not typical color or flow for well mixed JB. JB will/should flow out smooth during the cure time.
They make some pastes and Kwik type that's not as durable. Almost looks like some aluminum welding was done near the repair area.
But, obviously the case has been apart and reassembled per the black RTV sealant around the joint.

Wee van Cleef

· #15 · 3 mo ago

jettawreck said:
Yeah, that's not typical color or flow for well mixed JB. JB will/should flow out smooth during the cure time.
They make some pastes and Kwik type that's not as durable. Almost looks like some aluminum welding was done near the repair area.
But, obviously the case has been apart and reassembled per the black RTV sealant around the joint.

I think I see where you are going. Maybe a crack from overtorquing that cover bolt?

Centexhunter

Discussion Starter · #16 · 3 mo ago

Thanks everyone. You are making me feel a lot better about this. Think I’m going to do as suggested and try to get all (as much as possible) of the old stuff off and start from scratch. That way I know exactly how it was done and can only blame myself! 😁

Really appreciate all the advice. This forum is the best!

Reactions: 4

RCinNC

· #17 · 3 mo ago

I didn't even catch the RTV when I looked at the pic, so good eye, Jettawreck. It's been many years since I owned my 2012, but back when I did, I had an SW Motech skid plate. The front part of the skid plate was attached by removing the case cover screws and then bolting a couple support arms to the same bolt holes that attach the case cover. It wasn't the best design, but the idea was that the support arms were supposed to bend to absorb and impact before the case sustained any damage. I can't tell from the photos if those were the same holes that were used on my 2012 to attach the plate, but the design always looked like it was tailor made to damage the case if you hit something hard enough.

Reactions: 1

LazyRs

· #18 · 3 mo ago

Looks like Yamabond to me. Can you peel it off with a fingernail? If so, it’s not JB Weld… and in any case, it doesn’t look like JB Weld.

Reactions: 1

D.T.

· #19 · 3 mo ago

Wondered what happened??

That hole goes through to the other side.

Hopefully it's just a bad clutch gasket. That's what I'd do. Need to drain the coolant and oil though.

Not really the gasket, it's located away from the "stuff" somone put there. Maybe from the bolt?

I'm sick at home so, need something to do today.

D.T.

· #20 · 3 mo ago

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