A headache

Back in May I picked up a 1982 KZ750 LTD. It was claimed to have 8K miles and be a daily driver. It does run well to be sure but it has a non original odometer on it so the mileage is out the window. Still, it is in overall good shape and seemed worth the money I paid, $1200.





That's it the day I got it.

Slowly I've been working on it and as I don't ride it much (under 200 miles since I got it including the ride home)I'm still learning about what's at fault on it. I'm also doing a cafe inspired thing to it as time and money permits.





That's how it currently sits. To date I've swapped the bars, grips and mirrors plus moved the signals to the pivot points for the headlight bucket. The bike was also in need of exhaust studs as two were stripped and one was missing the nut entirely. When I went to do that chore I discovered it had a larger issue.



Now, yes I'd noticed the all-thread the day I bought it but without pulling the exhaust flange off it looked like a case of someone stripped the boss out and went with a size that worked. I was going to drill it bigger, heli-coil it and go back with the proper stud. It all seemed simple and straight forward until I saw that. Now I get to buy a new (to me) head and fix it. Trouble is, I've never had the head off a bike. Cars, I have no trouble with cars, even OHC cars haven't been an issue so I'm up for it. At least I hope so.

I also need to replace the exhaust. Somehow it ended up with the exhaust from a KZ550 which has the crossover pipe under my oil filter and no relief for the center stand so that's never been right. hitting a big bump causes the center stand to slap the pavement. Not to mention other problems.

For right now I'm just getting the exhaust to seal to the head by replacing the studs and living with the all-thread and adapting the exhaust to fit by relieving the mufflers where they interfere. It has fresh oil and a new filter so the crossover tube isn't an issue and shouldn't be for at least a decade at the current rate I'm putting miles on the bike.

Nice bike

I've taken heads off other bikes but not my 750. Shouldn't be a big deal though and I'm pretty sure you can do it with the motor in the frame. You can download a factory manual here -
mbsween.bike-night.com/kz750l3/index.html
courtesy of mbsween who is a member here. The main thing to watch for will be to tie up the cam chain and be absolutely sure you do the cam timing correctly when you reassemble. Replace the head gasket and watch for o rings. Check valve seats and clearances. Probably take you a day if you take it carefully.

Question - can you live with the exhaust studs the way they are ?

Good luck

How deep is the crack in the cylinders? (see arrow) Do you know if that was done in a crash? Ed

JR wrote: Nice bike

I've taken heads off other bikes but not my 750. Shouldn't be a big deal though and I'm pretty sure you can do it with the motor in the frame. You can download a factory manual here -
mbsween.bike-night.com/kz750l3/index.html
courtesy of mbsween who is a member here. The main thing to watch for will be to tie up the cam chain and be absolutely sure you do the cam timing correctly when you reassemble. Replace the head gasket and watch for o rings. Check valve seats and clearances. Probably take you a day if you take it carefully.

Question - can you live with the exhaust studs the way they are ?

Good luck

Thanks for the compliment and the linkage. Can I live with the studs the way they are? Well, naturally but the Billy-Bob stud isn't exactly the most secure feeling thing on the bike. My concern is that it's going to let go one of these days and have to be taken care of. Plus I figure that the prices of the parts are probably as low as they're ever going to be. Right now they're dirt cheap much the way that old Triumph bike parts were back in the late '80's and early '90's. If history repeats and the prices for KZ parts go up from here out I'll be wishing I'd just fixed it now anyway.

650ed wrote: How deep is the crack in the cylinders? (see arrow) Do you know if that was done in a crash? Ed

It's not a crack. That's a bit of oil on a casting seam and makes it look like a crack. Was it done in a crash? I'm laying my money on that it was but I know nothing for certain.