Water Pump Drive Gear Snapped Off Crankshaft!

[tobys 2 strokes]

Why not just weld something to the end that will attach to your slide hammer. welding on it would also tend to shrink it which would help free it. I hate drilling broke bolts so I always try welding a nut on them first If you have a wire feed you should be able to keep the crank from getting to hot.

[kxpegger]

Why not just weld something to the end that will attach to your slide hammer. welding on it would also tend to shrink it which would help free it. I hate drilling broke bolts so I always try welding a nut on them first If you have a wire feed you should be able to keep the crank from getting to hot.

It would be very difficult to weld something on to the broken shaft as it is recessed into the crank quite a bit. The end of the crank hole is tappered and the shaft is about another .080 or so inside. I checked with my machinist today and he does have some EDM capability but says it is very messy because of the coolant used. He's not sure if he can do with the crank still installed in the cases but said it would be no problem at all if the crank was out. I have to tear the top end off because of the sticking exhaust valves so I might as well just keep going! All this because of a $17.00 part failure!!!!!!

[Klammer]

Give these guys a call. Their ad says they remove broken bolts.
A&A auto machine shop
3297 Las Vegas Blvd. N.
Las Vegas, Nv. 89115
702 307-2535

The EDM process that your machinist has is called wire EDM and requires a coolant bath. The EDM process that is used by broken bolt and tap removal services does not require coolant and is much more portable.

[kxpegger]

Give these guys a call. Their ad says they remove broken bolts.
A&A auto machine shop
3297 Las Vegas Blvd. N.
Las Vegas, Nv. 89115
702 307-2535

The EDM process that your machinist has is called wire EDM and requires a coolant bath. The EDM process that is used by broken bolt and tap removal services does not require coolant and is much more portable.

10-4! And thanks again! I'll take a look.

[meat_man]

Theres an EDM that we use called a "hole popper". Not sure what the technical name is but it is used to put holes in metal by sending voltage/current through an electrode.  A lot of mold making shops have them and they require no submersion fluid.  This would probably be the best bet unless you have carbide bits and a steady hand.

[wierdo]

Gday, I had a similar problem in the same area, I had my motor rebuilt by a kawasaki dealer here in OZ and he had so much trouble getting the spur gear off ( siezed solid )He couldn't believe the trouble the little bastard caused so he took ( at no cost to me) the crank half to 2 engineering shops to try and get it off. even in a press there isn't enough material in the spur gear for it to maintain its structure under pressure it just cracked and broke bits off( teeth). i ended up having to buy a new crank half and spur gear.
I would be looking at why the bolt broke to start with. Have a good look at the end of the bolt piece that broke off, you should be able to tell if the bolt was faulty. if the bolt was cracked on installation it will be slightly darker where the crack started and lighter where it actually sheared off. check that the bolt was the correct grade for this application. just because it has grade 8, 12 etc written on it doesn't mean it actually is.( cheap chinese stuff)
best of luck mate..
 

[don46]

Gday, I had a similar problem in the same area, I had my motor rebuilt by a kawasaki dealer here in OZ and he had so much trouble getting the spur gear off ( siezed solid )He couldn't believe the trouble the little bastard caused so he took ( at no cost to me) the crank half to 2 engineering shops to try and get it off. even in a press there isn't enough material in the spur gear for it to maintain its structure under pressure it just cracked and broke bits off( teeth). i ended up having to buy a new crank half and spur gear.
I would be looking at why the bolt broke to start with. Have a good look at the end of the bolt piece that broke off, you should be able to tell if the bolt was faulty. if the bolt was cracked on installation it will be slightly darker where the crack started and lighter where it actually sheared off. check that the bolt was the correct grade for this application. just because it has grade 8, 12 etc written on it doesn't mean it actually is.( cheap chinese stuff)
best of luck mate..
 

There is no bolt, the gear and shaft are an intererence fit, so they fit really tight. I to had an issue with the gear and ended up getting a different crank. maybe drilling a person could get it out

[wierdo]

gday again, sorry for the misinformation, if you can drill through what is left of the gear then you will need a small stellite drill and a grease nipple and a good quality tap to suit( will need to be done on pedestal drill, dont use stellite in a hand drill) drill through whats left of the gear and tap  thread for the grease nipple, it might be a little hard at first ( use starter tap first)  but once you get through the  case hardening it should become a little easier and use a metal cutting compund, install nipple and use a high pressure power grease gun ( caterpillar dealers will have one) and pump till it pops. found this trick for bullets that have lodged in  gun barrels. 

[81cr450]

That is a kick asz idea, just like a pilot bearing.  YEA greasey nipples
that's the slickest solution to the problem I've heard

[Polar-Bus]

Give these guys a call. Their ad says they remove broken bolts.
A&A auto machine shop
3297 Las Vegas Blvd. N.
Las Vegas, Nv. 89115
702 307-2535

The EDM process that your machinist has is called wire EDM and requires a coolant bath. The EDM process that is used by broken bolt and tap removal services does not require coolant and is much more portable.

10-4! And thanks again! I'll take a look.

I do machining by trade as well, and have removed hundreds of broken bolts and studs. What exactly do you need machined out ? The primary crank gear bolt ? Should not be a difficult job. There might be some loctite securing the broken bolt, but all's I ever do is get the part square, indicate the OD, and initially use and endmill to bore a smaller hole, then using a drill start enlarging the hole. NEVER attempt to "free drill" a broken bolt, you won't get in perfectly centered ! So many people try this especially with broken steel bolts in aluminum cases/covers etc..  and the drill will always walk off the steel and destroy the surrounding aluminum.  When dealing with hardened materials, that gets more tricky and I will use solid carbide tooling.

[don46]

I suggest you go back to page one and look at the pictures, there is NO bolt

[alward25]

So, u need a crank half???

[Polar-Bus]

OK, still had no idea what I was looking at until I looked at my manual. Didn't know Kawi used a primary gear retained by a circlip rather than a bolt on the 500. There is nothing in the manual about installing or removing the wp drive gear, however you can buy it as a separate part. I suggest buying a new wp gear as now your machinist will have a shaft reference dia. to measure when machining out the old shaft.