1978 KZ400 B1
- Thread starter RobK
- Start date
Next up was figuring out the rearsets. I had bought some GSX-R units (I think from a '97 750) as they were $40 and that's probably cheaper then fabricating them myself. Plus I reckon them boys over in Japan probably worked out a few of the design issues that may have landed me in the proverbial quagmire.
The only issue was how to get them to work on a bike that wasn't designed for them.
As I mentioned in a previous post, the mounting brackets I welded on the frame were the wrong angle to begin with, so I need to extend the bottom so the bolt holes on the rearsets were vertical (I have since discovered that I may need to go even further). So I fabricated a couple extensions from 1/4 Aluminum.
The only issue was how to get them to work on a bike that wasn't designed for them.
As I mentioned in a previous post, the mounting brackets I welded on the frame were the wrong angle to begin with, so I need to extend the bottom so the bolt holes on the rearsets were vertical (I have since discovered that I may need to go even further). So I fabricated a couple extensions from 1/4 Aluminum.
I had been thinking day and night about how to get the brake to work without resorting to welding cable stays on the hub and frame.
Then I put everything together and started playing with the parts and (I think) I've got it working with the stock bar.
The second pic is what it looks like now. I'll have to wait until I'm done to see how the actual responsiveness of the brake is. I actually don't mind if it's less sensitive then before as it locked up more easily than I would have liked.
Then I put everything together and started playing with the parts and (I think) I've got it working with the stock bar.
The second pic is what it looks like now. I'll have to wait until I'm done to see how the actual responsiveness of the brake is. I actually don't mind if it's less sensitive then before as it locked up more easily than I would have liked.
Meanwhile I've been struggling with getting new fork springs. The old ones were mashed potatoes and I liked the idea of progressive springs as handling is one of my primary concerns. After all, the KZ ain't setting any 1/4 mile records!
Only problem was that since the KZ400 is sort of off the radar for performance parts the manufacturer didn't list the model. Someone from progressive was, however, good enough to send a spec sheet with all the sizes.
After a few sets of springs going back and forth to Dennis Kirk, I was finally able to get the right units.
In case anybody stumbles across this when doing a search for "kz400 progressive fork spring size", this is what I ordered...
Progressive Suspension Fork Springs
Dennis Kirk Part #: 58325
Manufacturer Part #: 111115
I was also very happy during the install that I remembered that I have tap puller in my plumbing box which doubled as a spring compressor perfectly. And the best part was I paid about a $1 for it from a garage sale a few years back.
I am suspicious that I have too much preload, but I want to get everything back together and test ride it before pulling out the grinder.
PS - I didn't mention to the missus that I 'borrowed' the measuring cup. While I cleaned it very carefully, she may fail to see the charm in using it to measure fork oil
Only problem was that since the KZ400 is sort of off the radar for performance parts the manufacturer didn't list the model. Someone from progressive was, however, good enough to send a spec sheet with all the sizes.
After a few sets of springs going back and forth to Dennis Kirk, I was finally able to get the right units.
In case anybody stumbles across this when doing a search for "kz400 progressive fork spring size", this is what I ordered...
Progressive Suspension Fork Springs
Dennis Kirk Part #: 58325
Manufacturer Part #: 111115
I was also very happy during the install that I remembered that I have tap puller in my plumbing box which doubled as a spring compressor perfectly. And the best part was I paid about a $1 for it from a garage sale a few years back.
I am suspicious that I have too much preload, but I want to get everything back together and test ride it before pulling out the grinder.
PS - I didn't mention to the missus that I 'borrowed' the measuring cup. While I cleaned it very carefully, she may fail to see the charm in using it to measure fork oil
Re: 1978 KZ400 B1 - splitting the case
Of all the problems that the bike had when I bought it, the clutch pushrod seal was the one that I least wanted to deal with.
Why? Because it pissed oil (probably a few ml's per minute) and the only way to replace it is to split the case.
One of the POs had lathered it in liquid gasket and for my part I used a NOS seal, sheered the ridge off and glued it into the recess.
My efforts kept it dry for a while, but just before I started this process of a full rebuild, that familiar smell came back at a stop - burning oil as it leaked from the pushrod seal.
Anyhow, this was my first foray into taking a bottom end off, and I'm happy to report, so far it's been fairly painless. It's actually been a lot of fun. Follow the manual, be clean, go slow, label everything and, well, so far so good.
I also recently picked up a lithium-ion impact driver (came as a combo with a drill) and it's proved its weight in gold. I tried it on the lugs on the truck and it was a no go - but for a little bike motor?? Perfect. I was able to get the engine sprocket retaining nut off without the special bracing tool, and managed all the Phillips screws on both sides without incident.
Of all the problems that the bike had when I bought it, the clutch pushrod seal was the one that I least wanted to deal with.
Why? Because it pissed oil (probably a few ml's per minute) and the only way to replace it is to split the case.
One of the POs had lathered it in liquid gasket and for my part I used a NOS seal, sheered the ridge off and glued it into the recess.
My efforts kept it dry for a while, but just before I started this process of a full rebuild, that familiar smell came back at a stop - burning oil as it leaked from the pushrod seal.
Anyhow, this was my first foray into taking a bottom end off, and I'm happy to report, so far it's been fairly painless. It's actually been a lot of fun. Follow the manual, be clean, go slow, label everything and, well, so far so good.
I also recently picked up a lithium-ion impact driver (came as a combo with a drill) and it's proved its weight in gold. I tried it on the lugs on the truck and it was a no go - but for a little bike motor?? Perfect. I was able to get the engine sprocket retaining nut off without the special bracing tool, and managed all the Phillips screws on both sides without incident.
The PO's efforts to stop the leak had a side effect - liquid gasket seeped through and seized the needle bearings.
Happily the bike was never used much. It still has less the 11k on the clock and I'm guessing that the repair was done pretty recently because despite frozen bearings there was no scoring on the shaft.
Happily the bike was never used much. It still has less the 11k on the clock and I'm guessing that the repair was done pretty recently because despite frozen bearings there was no scoring on the shaft.
Well new seal in place, motor cleaned, gear tolerances verified, liquid gasket applied and the case is back together. Over the next day or so, I want to finish rebuilding the motor and hopefully adjust the valves.
I think my goal of having her up and running by the new year may be difficult, but we'll see...
I think my goal of having her up and running by the new year may be difficult, but we'll see...
The Motor is in!
Happy day - as of 7:30 this morning, the motor is back in.
Finished re-assembling the motor, adjusted the valves and gave it another clean. The dirt just seemed endless. The block is still not 'from the factory' clean, but it's gonna get dirty again, so the show goes on.
One of my favorite touches already are the drilled out motor mounting plates.
At this stage, I need to take stock and put together a plan for completion. There's still a fair bit to do (mostly smaller jobs like the cluster and drilling out the sprocket cover), and I need to figure out which I do as I re-assemble and which I do after. This being Colorado, we have good riding days throughout winter and I sure miss being on the bike.
Happy day - as of 7:30 this morning, the motor is back in.
Finished re-assembling the motor, adjusted the valves and gave it another clean. The dirt just seemed endless. The block is still not 'from the factory' clean, but it's gonna get dirty again, so the show goes on.
One of my favorite touches already are the drilled out motor mounting plates.
At this stage, I need to take stock and put together a plan for completion. There's still a fair bit to do (mostly smaller jobs like the cluster and drilling out the sprocket cover), and I need to figure out which I do as I re-assemble and which I do after. This being Colorado, we have good riding days throughout winter and I sure miss being on the bike.
