TOPIC:

I bought a KZ550C4 last fall. I've been slowly gathering parts and tools to do some repairs to it this winter.

Last weekend I was going to replace the clutch. I followed the guide posted here and used an impact driver and all was going well until I snapped one of the screws in half. When all was said and done I busted two of the screws in half.

They are the top two screws. I notice that the holes for these two screws go all the way through so the back ends of the screws were exposed to air/water for 20+ years and I assume they are pretty rusted.

I put some kroil on the broken shafts and let it soak. I was going to try to file some flat edges and see if I can get them out with vice grips but other than than, does anyone have any suggestions? One of the shafts is pretty short so I don't have much to work with. If I damage the remaining exposed shaft then I'm gonna have to try to drill it out which I'm worried about attempting.

There are bolt extractor kits that can be bought. Basically a small drill bit and a wedge/punch gizmo. Drill hole through/into bolt, tap in gizmo and unscrew. Drilling out will need a helicoil kit to repair threads. Neither kit is that expensive. Filing slot in end and trying a second time might/should work.

Heat the broken ends with a propane torch. Add more Kroil. Tap with a hammer to break stiction. Turn gently to not break off more. Repeat often. Have plenty of patience. Beer optional. Or was it the other way around?

Thanks for the tips. I thought about the extractor kit but I read some cautions that they are brittle and prone to breaking, in which case they are too hard to drill out and then you're really screwed (no pun intended).

I did use a dremmel to cut a slot in the longer bolt and tried to use that with the impact driver but the metal is too soft and it just gave way.

I'll give the torch and patience a shot. Naturally with beer. =)

Extractors are brittle. If removing a large steel bolt would be worried. Am thinking a small aluminium bolt not an issue. I used one to remove a clutch spring bolt that snapped with no issues. Have also found when reversing drill bit it grabs and extracted bolt. Heat/fire and beer always good combos. lol

which cover are you refering to,left or right side of bike?

if the motor is not painted heat the area around the bolt and spray the bolt down with oil if the bolt is broke off flush use a left handed drill bit or e-z out take your time like everyone else said!i allways put anti-seize on any bolts that goe into aluminum.goodluck,happy wrenching!

Well, now I've done it.

I thought I had the longer screw coming out with some heat and vice grips but it turns out it wasn't coming out, it was just breaking more. I twisted the rest of the exposed shaft off.

So I tried an extractor bit but, sure enough, it snapped off in the shaft. I drilled the other screw out pretty easily but the one with the broken extractor in it has reisisted all my attempts to drill through it.

Oops, sorry for the lead on the extractor. I've never snapped an extractor off on an engine before. Snapped off in steel studs (1/2" dia) yes. That bolt is really in there. And unfortunately I got no fix on how to get pieces out without damaging cases. Any chance of drilling out from other side of bolt hole?

You can't cut that stuff.

Local machine shop with an EDM can get it out.

If you can find a small enough grinding tool you might be able to grind the broken tool out.

-Duck

Duck wrote:

If you can find a small enough grinding tool you might be able to grind the broken tool out.

Yeah I was thinking of heading to the store and seeing if I could find sort of bit for my dremmel that might be able to grind through it.

Ok, here is one of those strange tips that no one believes till they actually try it

Get some alum (try a swimming pool supply store), make a paste out of it and pack it in around the extractor, keep it fairly wet and the next day the extractor will be gone. This only works right if the screw extractor is broke off in aluminum, if you try it on steel it will make the hole bigger.

Some links:

www.ganoksin.com/orchid/archive/200409/msg00634.htm

www.metal-club.org/Remove.html

www.bhi.co.uk/hints/screws.htm

And I foumd the following info in a thread on the Home Shop Machinist board:

FOR removing broken drills or taps from ALUMINUM get some ordinary 'canning' alum from the grocery. Use a glass or ceramic cookware large enough to submerge piece. Bring water to a simmer in bowl and disolve all the alum the water will disslolve. Add the work piece with broken steel part, maintain simmer and water level. Gie it time and the broken steel will turn to mud or mush and wash out easily.

Home Shop Machinist

Post edited by: steell, at: 2006/01/22 14:03