Hole in crankcases, JB weld?

[DRZ4Hunned]

I had a crash a few months ago, so I'm in the process of getting the FZS600 back on the road. Unfortunately the crank cases were cracked where the surface meets the starter clutch cover. The impact caused the bolt to rip the casting out and has left a hole.

Is this area of the engine under high oil pressure? I was thinking maybe just use some JB weld or similar to repair it? Hopefully the other bolts will be enough to prevent a leak?

https://i.imgur.com/xiWF7yJ.png
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DRZ400-SM
FZS600

[solemnwarning]

Has it created a new hole, or merely pulled the threads out? If there's enough metal left, and the hole isn't an oilway or something, a helicoil might be an easy (and strong) solution.

[Beehive Bedlam]

I wouldn't trust JB weld.

Buy my scrap engine. 50 ponds.

[stinkwheel]

Sounds like a job for aluminium solder.

If there is a crack, you'll need to drill a stop-hole to prevent the crack propogating further then fill the crack and the hole.

You can fill huge defects with aluminium solder, you can also file it back flush, drill it and tap it.

You'll need a good source of heat like oxyacetylene or MAP gas (and some practice, the old cover would likely work if it's also alloy).

Durafix is a good brand.

https://youtu.be/n1njyuPBIH0
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[DRZ4Hunned]

[Teflon-Mike]

JB or Lumiweld etc can do a fantastic job, but the devil is in the detal, and like a lot of DIY not in the job, but the prep.

Crank-Cases generally don't have to stand too much 'stress' just keep the oil in, and I know of pistons fixed with Lumi-Weld, so it can stand some stress.. but its all dependent....

To do that job justice, I would probably want the motor torn down to the bare cases, so that I could first get them clean enough that I wasn't cooking oil oil and crap into the joint, and getting the heat into the case I wasn't cooking critical rubber seals or paper gaskets somewhere in there...

Full tear down, would make me ponder the merit of trying to salvage damaged crankcases, vs cost of replacing, nw or 2nd hand.

NOT tearing down... trying to fix in situ... I would be pondering the potential savings of not tearing down, vs the risk that working around whats still i situ would make the job more of a ball-ache, and likely result in it having to be done, and re-done and never getting properly done.. and in that, the merits of going a cold-cure, using a loaded epoxy, either a propriety gloop like metal-set or a home brew using araldite and aluminium filings etc, which will never be as good as an ali-weld or solder, but can do the job adequately if the wound s clean enough and the area not under too much stress.. a 'strategic' bodge basically. But even there, the prep is the key, and cleanliness next to sodliness, a full tear-down may still be in order, and alternative cases the better solution....

Your call....

Top tip... make sure there's o rocks around when you drop a dirt bike.. always look for the 'soft' landing! That's my advice... cant say I follow my own advice very well, judging by the amount of araldite and lumi-weld in my own dirt bikes over the last 30 years... bludi CoC's always find ROCKS to stick a section round! But still!
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My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[DRZ4Hunned]

I've decided to give JB weld a go, nothing to lose eh?

My only concern is the limited space to work in, the clutch mechanism looks like a PITA to remove, so I think I'll put something like a credit card behind it, and then fill the hole with JB weld.

Hopefully there isn't much pressurised oil in that area that will force it's way out any small gaps.

My DRZ has a big skid plate and case savers so I've not had any issues yet. Although I've never really had any crashes on it yet....
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DRZ400-SM
FZS600

[raesewell]

I pity the poor sod that buys the bike from the OP
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Yamaha FJR 1300 Normanton West Yorkshire

[monkeyman]

I think you are going to struggle to get a seal after on the mating face. I had something similar happen to me and I couldn't get it to seal

You going to want to try and grind a flat face one it
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Im not the best, but im in the top one
RM 250, Husky TE610, K1 GSXR 750

[Beehive Bedlam]

[A100man]

[DRZ4Hunned]

[monkeyman]

Well if you have mentioned that before, I would buy a new outer cover and JB it directly to the engine case, use Expoxy putty to fill the gap and jb over top. Will definitely work.

I saw something where someone basically cast an engine out of JB weld and that worked....
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Im not the best, but im in the top one
RM 250, Husky TE610, K1 GSXR 750

[DRZ4Hunned]

[skatefreak]

Dropped a generic Chinese 125 lump on the genny side and it cracked from the middle all the way up.
Got a scribe and scored a V to expose clean metal and increase the surface area.
Whacked in some JB weld and it was holding fine years after

[stinkwheel]

Should be noted that Allen Milliard uses aluminium solder to join the two crankcases he's bandsawed apart when he's making an inline 5 out of two kawasaki triples.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Hahadumball]

[sickpup]

[Islander]

[Hong Kong Phooey]

[DRZ4Hunned]