Soon to be a kat 600 fighter

[andoor]

JRK
Thanks for the pics!! I think I am going to stick with the 4-1 since I already changed over the oil pan and pickup to run it, but a 4-2 would be sweet! I am planning to cut down the muffler and the mid pipe to get everything tucked under the bike as far as possible.

I found a pic of another Kat that I am using as a reference. This one is a cut down 4-2, but I want a placement similar with my 4-1. I also will be modifying the back half of the frame similar to this, but running a custom seat made from both original seat sections cut into one. Instead of a glass tail like this.

Its getting there...

 

[andoor]

I started working on the seat. I cut down the 2 original seat pans by about 6 in. Now I just have to clean up the rear seat section, tie the two pans together somehow, and figure out what I have to make to use the stock latch. It will look something like this.

I have also decided on ostrich vinyl for the seat cover.

 

[andoor]

Not a whole lot of progress, but I have been working on the seat and also started looking at what I need to do to adapt one of the the mufflers of the stock 4-2 to make my shorty 4-1. My plan is to get the seat mostly done and the exhaust tacked together before I tear the whole thing down. I am borrowing a 110 welder for a bit so that should help with at least getting everything mocked up before the bike is stripped and brought to my dads place to use a real welder.

Got my new headlight in. I wanted to do something different... I figured this light would be better than some of the cheap streetfighter lights I was looking at on ebay that are only 25W. This one is 55W and I can get a 100W bulb if I need it.

 

[andoor]

Re: Soon to be a kat 600 fighter(F*CK!!!)

So I noticed a few weeks ago that the rear tire looked a little funny. It looked a little off center, but I figured the spacers on the rear axle were swapped around or missing. So last night I was tearing down the back of the bike and found that the swing-arm, and the mounting points on the frame are bent...

It is interesting because the bike didn't feel squirrely the few times I rode it, and one of my buddies rode the thing for a year with it like that and never noticed.

At this point I don't know what I am going to do. If I can find a frame for under 300 I will continue, but I don't think that is going to happen. I am already into the project for over $1000 for everything bike included, and I don't think I will be able to recoup that if I chose to sell everything off.


Swing-arm damage was hidden by the bearing cup.

The holes in the frame for the swinger bolt do not line up. I had to beat the crap out of the bolt to get it
out.

 

[crazypj]

Re: Soon to be a kat 600 fighter (F*CK!!!)

Looks to me like chain has been overtightened and busted swing arm bearings, plus general lack of maintenance?
Your going to need a swing arm, not a frame (if frame has damage, either weld a thrust washer to frame or just have it built up then file it flat)
You did try rotating the swing arm bolt to check it isn't bent and the frame to make sure it isn't burred up from swing arm moving about? (could be 'pushing' bolt way off center)
I've seen similar damage but not that bad.
It happens when the thrust washers get left out of bearing dust seals (not all have thrust washers so easy to overlook)

I know I have a GS500 swing arm (too short, too narrow for Kat)
I may have used the 600 ones I had, I fitted two into XS650's before I found out 500 would have been easier (I'll check what I have)
I did some mods to carbs on mine when I 'cleaned' them a few weeks ago.
I think speedo is busted though as it was showing 130+ a couple of times
On a 1995 Kat 600 plus 220+lbs of me on it, I don't think so ???

 

[thebronze]

Re: Soon to be a kat 600 fighter (F*CK!!!)

Yup... sort a swinger and be on Yer way... try a bandit 12... should slide in and allow the use of a wider rear rim/tire combo

 

[andoor]

Soon to be a kat 600 fighter (F*CK!!!)

Pj- the bike has had basically no maintenance from what I can tell. The bolt is bent a bit, but the left side of the frame where the swing arm mounts is also bent (the right side is ok). If I can bend it back I will try to resurface the faces to be parallel again. I guess I should try that first before I look into new frames.
Would you trust a repair like that??

The area has to be weak now that it was deformed. I was thinking of using some threaded rod and some bolts and washers to try and push out the swing arm mounting points to realign them.

 

[crazypj]

Re: Soon to be a kat 600 fighter (F*CK!!!)

I wouldn't worry about repairing a Kat frame, it's only mild steel so can be heated and tweaked, cut and welded as necessary.
I saw swing arm in shed but I couldn't get close enough to measure anything.
I don't know how frame could get tweaked on only one side unless you got a gorilla to remove swing arm and only pull pivot out on one side ;D

 

[andoor]

So I looked at the swing arm again and realized that the bushing I thought was trapped in there wasn't there. That would explain the marks on the bolt from digging into the roller bearings.

Some good news... I made a jig to straighten everything out again. With a little heat it worked pretty well I just need a swing arm to see if I went far enough. I want to get a good swing arm installed and measure everything up to see if it is straight. I am also throwing ideas around to add some bracing to the area.

 

[thebronze]

You are over thinking the problem... the chances that it really was "bent" where You describe are few and far between.... stick another arm in there and be done.. no sense in over engineering something that doesn't need it.... with a swing arm in there it will be strong enough.

 

[andoor]

You are over thinking the problem... the chances that it really was "bent" where You describe are few and far between.... stick another arm in there and be done.. no sense in over engineering something that doesn't need it.... with a swing arm in there it will be strong enough.

Well mark this one in the history books it was bent!! The bushings that are welded into the frame are only supported by thin sheet metal on each side. The left side was buckled and the bushing was not straight therefore I could not get the swingarm bolt (the new straight one) through both sides of the frame. With my jig I was able to push it out and get it straight again.

My conclusion is that at some point the swingarm was put back on missing the spacer that the left bearing rides on. This probably loosened up and when someone tried to retorque the swingam they ended up pulling the left side of the frame in while compressing and distorting the the left side of the swingarm.

 

[andoor]

After bending the frame back and installing the new swing arm everything is straight. I did the string alignment trick and all the measurements look good. Now I can get back to work.

 

[MotorbikeBruno]

Wow, i've been lurking on this thread for a while, came back and holy hell that was some work. Glad you got it sorted out. This build is going to be sick. Keep at it! ;D

 

[andoor]

Awesome eBay find. Mint R6 rear shock for like $80. I just have to make some spacers for the lower clevis. A R6 uses a 12mm bolt and the Kat is a 10mm. May also have to space he battery box up a bit to clear the reservoir.

This thing will give me a ton more adjustability, and it lowered the rear like 1.5in.

 

[andoor]

The new theme of this project is to spend as little money as possible to achieve what I want. That being said I made my new muffler from one half of the stock 4-2 setup. I think it came out great and it only cost me $3 for a reducer. Also I got a piece of scrap aluminum from work and took it over to my grandfathers place to make the spacers for the rear shock on his lathe.

The spacers

The right side stock muffler

Cut down and added an exhaust reducer to get the right OD for the collector

I also made a second baffle to keep some back pressure and quiet it down a bit more.

Cut and rolled a piece of 18g steel to clean up the overall look

I am thinking it is going to be to loud so I left the option of adding an in-pipe baffle on the inlet end if I need it.

 

[ejether]

Awesome eBay find. Mint R6 rear shock for like $80. I just have to make some spacers for the lower clevis. A R6 uses a 12mm bolt and the Kat is a 10mm. May also have to space he battery box up a bit to clear the reservoir.

This thing will give me a ton more adjustability, and it lowered the rear like 1.5in.

How is the progress coming?
I've got a Kat which I'm keeping stock, but I'm curious how the shock worked out and how much you had to modify the under bits.

 

[MotorbikeBruno]

The extra 18 gauge steel on the pipe was brilliant. Well done sir. I give you title of ballin' on a budget for now. haha Looking great and nice score on the shock.

 

[andoor]

Ejether- I won’t be able to ride it with the R6 shock for a while, but you don't have to mod much to make it work. You need the spacers I made and you have to move the battery box up like 1/8" that’s it.


Bruno- Thanks! I should change the title of this project to “ballin’ on a budget”

As for the progress I took a few weeks off around the holidays and just recently got back into it. I wanted to get the valves adjusted and the engine buttoned back up before I took it out of the frame. The valve shims were a pain and I had to wait a while to get the right sizes in. Now I know why kats were shims for only 3 years and then went back to regular adjusters.

I got the engine out last night. I am keeping it as a rolling chassis for now until I am done hacking up the frame and fabbing the new tail section and all the brackets for misc stuff. I am going to mock up everything before I strip it all down and start painting. That is a major lesson learned from my Honda project!

 

[crazypj]

The motor had shims because Yoshimura asked Suzuki to build a motor with higher rpm capability.
'Shimmed' GSX600F motors redline at 11,500 instead of 11,000. (not sure about GSX600R red-line?)
They still didn't work for racing, the rocker arms would crack or 'go over' the edge of shim with high lift 'race' cams (the 'finger' rockers are way lighter than the 'Y' shaped screw adjuster ones though)
It is why Suzuki dropped the GSX600R for a year though while they were designing the water cooled motor

 

[andoor]

Thanks for the history lesson PJ!!