Hi, Problems with a 2014 Honda CRF 125F. So we were out a Drumclog at the W/e and my daughter came in dropping oil everywhere after the chain came off. Subsequent examination show that the chain (or something stuck in it) has taken a nice bite out of the LHS crank case at the mating surface of the generator housing (couldn't have fecked it better if we'd tried!) have a wee look at the attached piccies as a salutary warning on chain maintenance... Anyhoo, to all you workshop gurus out there the question is this: Do we think this can be JB welded with the recovered pieces or am I just wishful thinking? The alternative is an entire new crankcase at God know's what price so I am keen to avoid that option if at all possible.
I know the correct response should be (said with most nerd like voice...) "the crankcase should be replaced"... But, if you have a majority of the pieces and can clean it really good and make sure no other pieces are floating around inside, I would JB weld it. I have a 1995 KX250 that I punched a rock through the oil drain section of the pan (don't ask, I only remember waking up). I JB welded it and it has held up perfect ever since. Changing the oil has an extra step of flipping the bike upside down though. the other option would be to get a very rude weld done. Both my KX and CRF250 are true testaments to quick, long term fixes...it's not cool until it looks like a junk yard dog. Just my 2p
If it was mine I’d have a go with JB Weld and then if that doesn’t work get it tig welded. Just make sure it’s spotlessly clean before using JB Weld.
agree with above from a cost and stress-saving approach - if you can get to a situation where it's oil-tight again then it looks like the best solution for you. Affected strength/integrity of crankcase doesn't look ilke an issue/fingers crossed. How bad is the generator "crankcase capping"?.
Ya, JB Weld seems to be the growing plan. Its just a hole after all, doesn't hold any pressure or loading. My only concern is the effectiveness of JB, will it hold, is it any good, what's the best method, can I or should I use a bracing or supporting piece to strengthen the repair? Questions Questions.... I have never used the stuff before and have read/watched/heard conflicting stories; I suppose the real test is to suck it and see! Its just a total PITA! We have been out twice only this season and the first time out the Lad's 250 Husky dropped a valve, now this! AS the yanks say 2 for 2. The Husky is still in the local garage awaiting parts from KTM that never seem to get to UK shores. The 2025 riding season will be a memorable one for all the wrong reasons...Hohumm, should have taught them Chess, slightly cheaper!
i'm not sure if this amusing story will instill confidence, but I go back to around 1979 when I was running a Fiat 500 among other cars. A colleague, suitably impressed by the little mouse, bought one himself, but it was a bit more of an old banger. I gave it a look over for him, and couldn't understand why almost half the gearbox clutch housing was a dull grey/white colour. On closer inspection, a previous owner had decided to fabricate/layup many times, a repair to the smashed bell housing using plastic padding! I couldn't confirm, but it had to be at least 10 mm thick in places, and you could tell by the age of it that it had done the job adequately for sometime.
I've had riding seasons very similar... The best way to clean in my opinion is first scrubbing with acetone then with isopropyl alcohol to get residues off. I would use a heat gun or a hair dryer to gently warm the parts, then after putting together, gently heat again to help kick off. I would probably do one piece at a time because when I get too much stuff it will end up being thrown all over my garage...
I did a hole in my vans diesel fuel rail about 4 years ago with JB Weld and it’s held up absolutely fine. Degrease with acetone or brake cleaner several times to be certain it’s clean and use some aluminium repair mesh if you want to reinforce it to be sure.
JB weld is good stuff and I would try it but I would also, if possible try to reinforce by JB welding extra material onto the outside as long as there's clearance.
I've seen a 998 crankcase that had been patched with JB weld after the chain let go, wasn't a tidy job but has been there 10yrs or more now.
