Testarossa's 78 KZ1000 Fighter Build

Les, I wasn't aware of the rod test for the crank when I assembled the motor. I will check that when I install the 1075 kit. However the crank is welded. I would hope that who ever welded it would have verified that it wasn't twisted at the time. Hmmm...

Mark, Dyna 2000 is installed. The clutch basket springs were found to be bad and were replaced at the time with the APE heavy duty kit. As for the carb issue, it's definitely a transition issue. The transition from idle to just getting on the throttle. You can always hear a slurping sound from the carbs when it happens. It seems to be a little better with the #15 pilots in. I rode it to work this morning and it was just OK. We'll see how she does on the way home when it's warm outside.

testarossa wrote: Les, I wasn't aware of the rod test for the crank when I assembled the motor. I will check that when I install the 1075 kit. However the crank is welded. I would hope that who ever welded it would have verified that it wasn't twisted at the time. Hmmm...

Mark, Dyna 2000 is installed. The clutch basket springs were found to be bad and were replaced at the time with the APE heavy duty kit. As for the carb issue, it's definitely a transition issue. The transition from idle to just getting on the throttle. You can always hear a slurping sound from the carbs when it happens. It seems to be a little better with the #15 pilots in. I rode it to work this morning and it was just OK. We'll see how she does on the way home when it's warm outside.

if you could just weld a crank i would do it myself. making sure its straight first is a must. im suprised you didnt know this test, and im not being sarcastic. i guess we all learn a lil each day.

also, what made you go with the 2000 vs the s? just curious of pros and cons. thanks. Joe

Joe, trust me that I had no reason worry about this crank being twisted. I know the guy who sold it to me, and he assures me that it was professionally welded. He ran it in his personal bike and it performed just fine. The problem is likely in my transmission or the engagement between the trans gears and the crankshaft output gear. If it's even a problem. Like I said I have never ridden a stock KZ1000. It's a very slight vibration. Did anyone even notice it in my videos? I can assure you that it's there every time I rev the bike and then release the throttle. Not a new development.

As for the Dyna 2000 vs S I already addressed that in this thread. However, I'll re-visit it again. I like the rev limiter and the ability to select different advance curves. You can also program custom advance curves with their programming kit. One other advantage is the digital tachometer output. I'm using that to output rpm to my datalogger. I already needed coils and the 2000 kit includes them. In the end, when you include the purcase of coils, it didn't cost much more than the Dyna S so I went for it.

I'm just wondering what the symptoms of a twisted crank might be? i think this is a good topic for discusion and learning.
the pistons would reach tdc at dif times and cause the ign timeing to be slightly dif for each 1 right. if the points were set dif from 1/3,2/4 this would create the same scenario wouldn't it. would this create a vibration or just a slight power dif. ?
i'm thinking a vibration would more likely be caused if the crank, or something was out of true, or out of balance ?
anyone ever experience this?

BTW would a twisted crank not vibrate on acceleration but only on decel? I think you would feel it all the time. The bike idles just fine, and accelerates very smoothly.

testarossa wrote: ...
O-52 needle jet;
Not sure on this one, whatever is in there is in there.

5DL31 jet needle (with clip in middle #3 position);
Yes on the needle ID, but currently the clip is on the 5th(richest) position. Previously it was on the 4th with similar results only the AFR was a little lean from 1/4-3/4 throttle. Maybe I need to go up one more main jet size and get the needles back to the third clip. Currently running #125 mains, pods, 4-1 exhaust, and I'm at sea level.(Houston)

...installed a Dyna 2000 ignition. All advance happens electronically. I timed it with a strobe when installed, and verified advance function at that time. I guess I could re-visit this just to make sure nothing has gone wrong.[/color]....

Can't argue with the AFR readings, but needing 5th clip position seems unusual.

Imo it's doubtful that a larger main jet will have any significant influence with regard to different clip positions, as the clip position governs mixture almost exclusively until near full throttle, and should produce the same mixture regardless of main jet size.

Am wondering if perhaps the jet needle is worn (especially in the tip area) and/or the needle jet is worn (enlarged) so as to produce an excessively rich mixture in transition from the pilot circuit.

FWIW, my bikes express different engine speed harmonics, whereby for example the mirrors vibrate during a certain rpm range. Just the personality of the bike, and different from the sewing machine smoothness of a Goldwing.

Having no experience with the Dyna 2000, am wondering whether it might be feasible to slightly adjust the advance curve in the vibration prone rpm range?

Good Fortune!

Carb -- Sometimes the pad at bottom of enrichener plunger becomes worn and fails to completely seal the starter fuel passage when the choke lever is pushed all the way down. Am thinking this condition might contribute to the excessive richness coming off idle.

Vibration -- If not already done, would assure that the header pipe or collector isn't touching anything underneath the engine, such as a drain bolt. And that the muffler is attached in a fashion whereby vibration doesn't reach the frame.
I use a small rubber motor mount between the muffler and frame, which make a huge difference toward reducing trasfer of vibration into the chassis.

Good Fortune!

Just buy some Keihin CR's already! :lol:

900 cranks do tend to buzz a bit compared to 1000 cranks i would think a twisted crank would behave the same whether its reving up or shutting down.
id go through bike one end to other and check for lose bolts

DoubleDub wrote: Just buy some Keihin CR's already! :lol:

Can I borrow $700 from you? Actually, the CR's are in the long range plan.

Patton, I was wondering about the influence of the enrichener in this equation. I just cleaned them up and put them back in place. Maybe I need to re-assess. Also, it is possible to adjust the timing on the Dyna. It can be advanced/retarded via the pickup plate, and it comes with a couple of different curves. Also, with their software you can program your own curve, not that I have any business trying to figure that out at this point.

The jet needles are worn to the point that the anodizing has been removed lightly, but no more. As for the needle jets, I can only assume that they are as worn as the needles. As I understand it, needle jets get oval shaped over time due to the needle sliding up and down while being pulled against the motor side of the jet by the in-rushing air. I could measure just about anything with the tools available to me at work, but I can't find specifications for jet orifices or needle tapers, diameters, etc. I'm not sure if these carbs are even worth the trouble of trying to track down new jet needles, and needle jets. I may just start saving for a set of new carburetors.

BTW, my muffler to frame mount has 3/8" thick rubber bushings on it already, and the header doesn't touch anything else but the head. Another good idea that I have already ruled out.

Dangit, wireman beat me to it, It would vibrate up and down on r's and a 900 crank doe's buzz a little more than a 1000. I agree that it just sounds harmonic vibrations. I have seen a cam chain cause it, don't remember the circumstances be it loose or tight, wasn't my bike but a look see couldn't hurt;)

les holt wrote: Dangit, wireman beat me to it, It would vibrate up and down on r's and a 900 crank doe's buzz a little more than a 1000. I agree that it just sounds harmonic vibrations. I have seen a cam chain cause it, don't remember the circumstances be it loose or tight, wasn't my bike but a look see couldn't hurt;)

I'm due for a valve clearance check, oil change, and tensioner adjustment anyway. Maybe I can get to that this weekend. I did put a new cam chain in when I had the motor apart. Do they stretch a lot just after they're first installed?