Testarossa's 78 KZ1000 Fighter Build

porchev914 wrote:

WooHoo! I mean, most of that stuff is to be expected after resurecting an old, neglected bike after so long. That sucks about the tail light though I hope it's salvagable. If you need, I have a working set of VM26's that you're welcome to use to help sort things out

My thoughts exactly. I love the darned thing, and I'm not surprised by any of this. Thanks for the offer, but I'll get mine sorted. I worked it out in my head while cooking supper tonight.

Carb boot on #3 has a leak. This leads to a lean condition, and a lack of vacuum. While trying to sync the carbs #3 was showing significantly lower vacuum than the others. I had to adjust that slide so far down that it actually closes and is pushing the others up causing the rise in idle speed. The totally closed slide also leads to a negative pressure condition in the float bowl on that carb. This would explain the pulsing vacuum on the #3 vent. In reality, by syncing my carbs with a bad boot, I am actually un-syncing them.

Does my assessment sound right? It actually seemed to rev a little more freely when just bench synced. Once I get past this, I can work out the jets.

As for the taillight, I'm trying to open it to see what's going on in there. If its lost, then I'll get another.

maybe the boot just needs a little sealer around the mounting flange.the backfire when turning the ignition on could be a spike through the system.

leon

Geeeeeeze Leon where have you been hiding out at?

silly ?...but...when the idle set screw is backed off to the cable stopped...is there any play in the cable...ie...can you stick a screwdriver against the bottom carb cable nut stop,and pry it to have extra play...ie..slack in resting cable...tahn the set screw takes that slack and sets idel...ect...i had to mess with mine just recently and finally...set the cable loose,then set screw....sounds simple but...happens...before that iwas always resetting the idle on rides till i figured out i had revesed the tension setting proccess.....testarossa wrote:

Ok, it looks like I'm in for a new set of carb boots. I should have got them in the first place, but mine looked real good. After syncing the carbs, the lowest idle that I can achieve is 1500. I also noticed that the vent on the #3 carb is drawing a substantial vacuum, but the other vents have none. Also, after I cut it off, the next time I put the ignition on, I get a small backfire through the exhaust. Do these sound like symptoms of leaky carb boots?

Allow me to clarify on thing. When I say 1500 rpm idle, I mean that the idle stop screw is completely backed out and this is as slow as the engine will turn over. I DO NOT mean to say that I can only keep it running at 1500.

porchev914 wrote:

Geeeeeeze Leon where have you been hiding out at?

He's under my bike, drilling holes in the carb boots.

trianglelaguna wrote:

silly ?...but...when the idle set screw is backed off to the cable stopped...is there any play in the cable...ie...can you stick a screwdriver against the bottom carb cable nut stop,and pry it to have extra play...ie..slack in resting cable...tahn the set screw takes that slack and sets idel...ect...i had to mess with mine just recently and finally...set the cable loose,then set screw....sounds simple but...happens...before that iwas always resetting the idle on rides till i figured out i had revesed the tension setting proccess

I thought about that, so I tried it with the cables totally disconnected with the same result. I believe that the number three slide is adjusted so far down that it presses the others up through the linkage. Effectively the slide in number 3 is acting as the stop.

I ordered a set of new carb boots and a new taillight Monday. Maybe if I'm lucky, I'll see them on Wednesday. I couldn't find anything obviously wrong with the taillight. Everything on the circuit board looks new. In retrospect, I was kinda tough on that first one while figuring out mounting and such. It hit the floor more than once.

i hope your parts show up today .
i have to wait until thursday before i get my seals for my rear r1 caliper .i think i have some pistons sticking and causing my brake to drag.
keep us posted,

leon

531blackbanshee wrote:

i hope your parts show up today .
i have to wait until thursday before i get my seals for my rear r1 caliper .i think i have some pistons sticking and causing my brake to drag.
keep us posted,

leon

I had the exact same problem with my GSXR rear caliper. I took it apart and found a lot of white crusty stuff behind the seals. Once I cleaned that junk out and got the crud off the outside of the pistons it works fine.

Now for my funny brake story. I wasn't going to tell this one but what the heck. Maybe it will make somebody check before they hit the road.

So in preperation for my maiden voyage on the old KZ, I worked late into the night last Saturday to get the brakes well sorted. I had picked up a complete set of Galfer pads for about $130 and a fresh bottle of DOT 4. I figure that I have to do it right, right? Saturday night I install the new pads and attempt to bleed the brakes. No Joy.

Cut to Sunday a.m. and I dismantle the master cylinder, clean it out, and re-bleed. It's working good now, so lets have a ride. With much trepidation, I ease the clutch out and roll the old KZ out under her own power for the first time this millenium. Happy, yessir I am very happy. Stumbles, hiccups and all. Now I was being very careful and just took her up to 4000rpm in first and then eased on the brakes. Stop and look. Everything still attached, check. Now we'll try second gear. Roll out again and ease through first, and I instinctively upshift without the clutch. Pure butter, this thing shifts better than the ZX-10r which admittedly needs an oil change at this point. Agian, I ease to a stop with no drama.

Now it's time to give her the beans a little. So I hit the main drag in my subdivision. First gear, second gear, third gear, fourth gear, I'm feeling it. Hell yeah, I'm rollin' now baby. Ok, here comes the 4 way stop at the end of the street. Time to see how the binders work from about 35mph now. I grab a little front brake, and it starts to stop, then lets go, and then grabs again. Huh, what was that about? At that moment I see one of the brake pad shims fly past my head. How did that come out? I stop the bike and back up to get the shim out of the road. Damn, that thing looks like a Pringles potato chip.

Carefully back to the house to asses the problem. Stopping with only the rear brake now just to make sure I didn't spit the front pads out. When I get the caliper off and have a look at the pads, I discovered that the outside pad on the right front caliper was installed backward so the shim was grabbing the rotor. Lesson learned, don't work tired. I have put brakes on every kind of wheeled vehicle, and can do it blindfolded. I still missed this. I have been burning the midnight oil a little here lately to try and get this bike running. Sometimes it's better to go easy after a day of hitting the ground running at 4:30 am.

In the end, it was no harm, no foul, because I worked my way up to speed incrementally. I have a plan to gradually test everything up to highway speed. Now if you just get the bike running, hit the highway and let the big dog eat all the way to 70 only to discover that you have no brakes. :blink: :side:

close call. glad u were smart enough to ease into the braking.
we all make mistakes. mine was braking tooo hard on a cold track. :woohoo:

mark1122 wrote:

close call. glad u were smart enough to ease into the braking.
we all make mistakes. mine was braking tooo hard on a cold track. :woohoo:

Love the new avatar Mark. Too bad you earned some xrays on the track day. The last time I had a spill on a bike it was due to cold asphalt and cold tires as well. Fortunately for me I didn't break anything on that one.

Well, I got the new carb boots and taillight today. I got straight to work installing the boots. I'll say that it definitely needed them. Idle improved immediately, but still didn't solve my problem. Once again I had a brainstorm while cooking dinner. I'm surprised that no one caught this yet.

1978 KZ1000 A2 would have a vacuum petcock when new, right? Well my bike is an A2 but the tank that I got with it was from an LTD. Also the tank that I adapted was from a 1978 KZ 750 twin. Neither of these models had vacuum petcocks. Soooo, that supposed vent on #3 that was drawing a vacuum should have been hooked up to the petcock that no longer was.

I threw a vacuum cap on that port, fired her up and voila, throttle response. I was trying to tune for a massive vacuum leak. After I re-re-bench synced, and then vacuum synced, I went for another spin. Oh yeah, the mule team is pullin' now. Instant wood. I don't have 'em all quite pulling the same direction, but I'm well on my way now.