'76 KZ900 (ZRX1200R) Build

NakedFun wrote: Mark,

I appreciate the feedback. My SV1000 (piped, air intake, and fuel tuner) is my TQ monster! I get what you are saying, and I plan on changing pretty much all the components (oil pump, timing components, bearings, etc...) anyway, but if I can forego the bore job, to retain as much cylinder thickness as I can, I was thinking about doing it. Will redo the head, and spec out everything (cam lobes, valve stems, etc..) to see if I should replace or not. Since I got screwed on my 28 pumpers, will keep my 26's and pod them, with my exhaust and call it good....unless cams are in my future. So no one makes a non-1015 high compression piston? Even if it is a .5mm over bore?

Cory

yes there is . sorry i forgot the obvious.

Wiseco makes a 10.25:1 1015 kit for $576 with head gasket from APE. just bore and go . using a 903 cyl.

kzzone.com/pistons.html

no point changing the oil pump unless u have a problem with the current unit. u can install a thinner internal gasket for a tighter spec fit and an improved flow. there is a clearance spec in the manual.
just make sure u replace any internal part that has a rubber component to it. the rubber gets hard and brittle with many heat cyles and can deteriorate/brake up .

So although I have been waiting to get back into the shop this weekend and do more fabricating, I have been doing some shopping:

Orded a custom HEL brake line and clutch line kits (green with gold fittings)
Got my smoked CBR600RR taillight
New tank rubbers...(sounds dirty doesn't it?)
Lots of stainless steel hardware.
Ducati 848 Clutch Slave

Now I have some cool ideas in the works for the tail section and I think I may have a found a super clean way to mount a hydraulic slave into the stock cover with out using the AC slave or cutting it up much. I do have my ZRX slave that I can use if I get a clutch plate made or from PMFR. There will be more pictures to come...

Cory

Ok, so a busy weekend, but didn't get as far as I had hoped.

First off, looked at the gusset interference with the seat lock. Sure enough, it does interfere. This is just an FYI for anyone how will be doing this work...

Before:


After:


After that, worked on the steering damper. Ended up blocking the factory mounts for the oil cooler. Will have to shift the oil cooler down, and make new mounts. I think it looks nice and works well.




Spent the rest of the time fabricating an under tail that bolts in without modification, and is clean and keeps tire sling out from under the seat as much as possible. I came up with this:



It is made out of .125" (1/8") sheet, so it is a little heave, but very rigid and should not get damaged if something gets kicked up. It still needs the licence tabs, but didn't have my plate along to verify fit. Will have to wait until next weekend. Here it is bolted to the bike with stainless fasteners. My CBR600RR smoked LED tail light is also in place. Used "D" rubber weather stripping to create a nice fit into the tail.





So last on the list, beside getting the engine bolted back in, I decided to make a tab for the RH side cover instead of using the broken, black plastic cubby holder. It came out nice, but my backside weld is not pretty looking, but is solid...hate ugly welds...




So thoughts on it so far? Building a custom kick stand, and trying to put the money together to get my exhaust components for that phase...

Cory

I don't know why the pics are rotated, sorry.....

Cory

Lighten up your subframe shield with a composite part The fab looks good and you are making awesome progress!
Adam

Adam,

Besides my composites work back in college, I just don't have the ability to work with the resin like you I am afraid! Now metal, I can work with..... lol

Cory

Make sure to add some gussets and fully weld the taillight hanger section of your under tail. It may sound silly but my first one fell apart due to vibrations and the back tire ate my taillight. Mine was also made from 1/8" plate. I believe Les Holt can tell a similar story.

Yeah, got a nice tire mark on my plate from it. Seems all better now and I'm using 16 ga. mild steel, just added an extra mounting plate welded on the top of it using the 2 holes in the back of the little trunk area to mount it to. stiffened it up quite a bit, no issues since.

Les

I appreciate the feedback, but where are you saying I need to add additional gusseting? I have gussets fully welded at the breakover point in the plate that are welded into the 1/8" thick, 1" bar stock I made the taillight section out of? The plate is mounted to the bike with 4 x 6 mm bolts at the rubber siolator section and two 8 mm bolts at the brace where the fender meets the plastic forward fender.

Cory

I made my own taillight / plate hanger and it too cracked from vibration at about 1000 miles...back tire marked up my license plate. Mine was made from very thick aluminum plate...can't remember how thick though. I'm really surprised to hear that the steel ones broke too.

Really surprised by all this. I understand the forces that are exerted on the tail section, but to me it sounds like the material used is finding a natural frequency during operation and causing a material fatique failure. This most likely would be due to a combination of material, design, functional application and enviromental (i.e. read vibrationsal influence from operation of the bike). I'll take a look and see if there is any additional support I can provide the light structure. One thing to think abolut is that the thicker material is also heavier, which would increase the aplitude of the natural frequency of that part and cause fatque sooner, so that may not be the answer either. I have only dabbed in NVH studies of structures at work, and by no means know what I am doing!

Cory

japan.webike.net/products/1522740.html

I found this, like the infamous Sanctuary fender eliminator, but made by PMC in Japan. I don't see much bracing, but seems close to what I ended up building other than the taillight piece. Anyone have this kit installed? Feedback?

Cory