Broken shift fork

Thinking about buying a KZ650 with a broken shift fork... how much money/headache will this cost?

How much money, depends on how much of the work you intend to do yourself. You will have to remove the motor, flip it over and split the crankcase to get to the transmission. Expect to get bent over and done really hard if you have a shop do it. I've always been an advocate of doing the work yourself. If you can pull the job off with help from a manual and a basic set of tools go for it. Do it yourself and you are in to it for the price of a shift fork and a couple of gaskets. Doubt very much they are expensive. How does the seller know it is a bad shift fork? 2nd gear problems are usually the tranny itself. There are oodles of used parts available on the net, so even a replacement tranny can't go more than a couple of hundred dollars. If the bike is super cheap, go for it. A few hours of your work and some new parts and you got a killer bike for a steal.

I think you have three shift forks. Two are on a rod and the third is on the shift drum. I had an engine out and replaced one yesterday in about three hours start to finish. I would leave the top end on the engine if it runs OK... Essentially, you take off the engine covers. Inner sprocket cover, stator cover, inner points cover, clutch cover and kicker cover. Flip the engine over, remove the oil pan and oil pump then split the cases. On a KZ900, you remove five 6mm bolts on the top, about 17 6mm bolts on the bottom and the outer eight 8mm bolts to the sides of the crankshaft. You then use three 8mm bolts to pry the cases apart. Once apart, it depends on which shift fork is broken. If it is the one on the drum, you remove the drum from the lower case... it isn't too hard and if is one of the two on the fork shaft, the shaft pulls right out. You then put the bike in neutral (detent on pin drum on outer shift mechanism is at 8'oclock" and slide the forks back into place and put the bottom of the case back on the top with some Hondabond HT, Threebond 1203 or Yamabond #4 or other case sealer on the mating surface. You will then have to scrape the old gasket material off the engine cover mating surfaces and reinstall them as well as the other small parts.

Of course, taking the engine out of the bike takes a bit of work but I can do it in about two hours I guess by myself. I use a furniture moving dolly and transmission jack.

If you haven't done this stuff yourself, you might want to pick up a Clymers... Where are you located? Perhaps someone is in the area who has done this and could help...

Post edited by: wiredgeorge, at: 2006/02/06 17:53

ROM... sorry I posted my note as you about covered it. Your's wasn't posted when I was typing my longish reply. I don't know about 650 transmissions but I suspect you could pick one up for under $75 and perhaps under $50. I keep spare KZ900/1000 transmissions in my shop for just this purpose. Cheers!

Are you sure the shift fork is really broken? The 650 (ao) has a neutral finder mechanism, you can´t switch up to 2nd and above unless the bike is rolling (engine running isn´t enough), maybe that could be the problem?

Splitting the cases on a 650 requires removal of the complete clutch assy (clutch plates and discs, basket and hub], removal of the oil pump, secondary shaft and starter clutch as well as what George mentions. The secondary shaft sits in the lower case only and is tied to the crank through the primary chain, can´t pull the cases apart without removing the shaft - and you can´t remove the shaft without removing the clutch assy. It´s not too difficult if you´re mechanically inclined, but as Rom says a shop will skin you, if they even want to work on the bike that is.

No worries, mate. Your post usually have the detail that mine lack. Your probably right about tranny prices being lower than my estimate. I think all relies agree a shop will rape you bad. My first bike was a KZ650 and I made $2.50 per hour, Canadian!! I had no choice but but do my own work. Thank the gods that KZ's are very simple to work on. A manual and a basic set of sockets, wrenches and screwdrivers and your set. Leaving engine in one piece means you may require assistance in removing and replacing motor thats all.

I work on complete engines by myself all the time. The secret is a furniture moving dolly. The dolly is a rectangle of wood with carpet covering the ends and the dolly is on casters and is very strong. About $20 in a home improvement store. You just need to be strong enough to slightly lower or raise the full engine and flipping it over isn't hard as the opening in the dolly accomodates the engine well. The full engine weighs about 225 lbs so it isn't all that heavy; only awkward.

well... I don't think I'll be buying the bike, although it does look to be a pretty good deal. THe shift fork issue will keep me from riding it until I have put a weekend's work in, that and the girlfriend says no new toys until I get rid of an old one.