Testarossa's 78 KZ1000 Fighter Build

not sure if I missed it but.. is the vibration something you HEAR or something you FEEL or both? Could help diagnose.

or did you just forget to tighten the rear axle? :laugh:

While the air screw vs mixture screw carbs have slightly different pilot circuits (first image), the cleaning method (second image) illustrates the same principles to be used on either.

Please wear goggles when spraying carb cleaner, as it will invariably backfire into the eyes.







Good Fortune!

Patton wrote: Am thinking richer pilot circuit mixture should result in a cooler running cylinder at lower rpm range.

Hopefully, perfecting the pilot circuit will resolve the stumble.

Good Fortune!

I thought so too. As a matter of fact, I started by turning that screw in (leaner) which resulted in cooler temps still. Another half turn in resulted in 200*F. So I suspended my disbelief and started turning it out. (richer) Lo and behold, the temp started to come up. I guess that the amount of fuel getting through at idle was so low that I barely had a fire in that cylinder. Once I got that screw out a full turn or so, the temp was running 500* just like the other three cylinders. It shouldn't be normal to have three cylinders with the mixture screws at one turn out, and one at two turns, right?


Nelson, the vibration is more feel than sound, but you can definitely hear it when you are on the bike. One wonders if it couldn't be somewhat related to the carburetor issue. Hmmmm...
BTW, the rear axle is tight, I used a torque wrench, and that cotter pin is still there.

Vibration.... Something I learned in my build and confirmed through Larry and Plum...

I'm fairly anal about keeping her in top condition, you should hear the crap I receive from those two about consistently tweaking, syncing and short time frames between shim changes etc.... :whistle: It's not purdy....

Anyhoot, after about 2500 miles, I started feeling high frequency vibrations in my feet and noticed my fingers would go numb rather quickly, at least quicker then normal... Now I didn't have any tank slapper effects or wobbling, just high frequency vibrations I actually could feel.

I like you have mentioned thought oh hell no, I just checked that last week... As pointed out to me with a size 10 in my arse, do it again.... Yup, guess what I found, sure enough....

Anyhoot, went through every freaking bolt and screw on the engine case bolts, frame mounts, fork tube clamps, swingarm, exhaust etc... and was quite surprise how many had backed out off torque specs... Problem went away.

I still think those two flew to AZ, broke into my garage and sabotaged my KZ just so they could bust my balls and make fun of me.... :blush: :laugh:

Another thing to check... Remove ignition plate cover.
Observing the crankshaft end bolt, is it moving in & out irregularly as you ramp up/down the throttle?

Just some thoughts... Definitely let us know what you find...

OMR

Old Man Rock wrote: Vibration.... Something I learned in my build and confirmed through Larry and Plum...

I'm fairly anal about keeping her in top condition, you should hear the crap I receive from those two about consistently tweaking, syncing and short time frames between shim changes etc.... :whistle: It's not purdy....

Anyhoot, after about 2500 miles, I started feeling high frequency vibrations in my feet and noticed my fingers would go numb rather quickly, at least quicker then normal... Now I didn't have any tank slapper effects or wobbling, just high frequency vibrations I actually could feel.

I like you have mentioned thought oh hell no, I just checked that last week... As pointed out to me with a size 10 in my arse, do it again.... Yup, guess what I found, sure enough....

Anyhoot, went through every freaking bolt and screw on the engine case bolts, frame mounts, fork tube clamps, swingarm, exhaust etc... and was quite surprise how many had backed out off torque specs... Problem went away.

I still think those two flew to AZ, broke into my garage and sabotaged my KZ just so they could bust my balls and make fun of me.... :blush: :laugh:

Another thing to check... Remove ignition plate cover.
Observing the crankshaft end bolt, is it moving in & out irregularly as you ramp up/down the throttle?

Just some thoughts... Definitely let us know what you find...

OMR

We'll spare no expensive to torment Dave.... including airline tickets to Az, taxi, hiring a burglar to get us into Dave's garage.... :lol:

Good ideas there. I want play with the timing anyway, once I get my carburetor issues resolved. You know, we're probably a lot alike in the constant tweaking thing. Once I get an idea in my head, I start thinking, "If I only had that screwdriver with me, I'd pull over and adjust that..."

It will likely be early next week before I can do anything else. I have a busy weekend with Cub Scouts activities. Looks like I may get to be a Den Leader next year since our current guys wife had a stroke. I'm trying to chip in as much as I can to keep things running smooth, so family first as they say.

So my gameplan for next week is to clean out that pilot circuit on #2. Then re-tune mixture screws, and log some O2 sensor data. Hopefully the AFR will stay above 12.5:1 on first throttle application. Then if that works out, pull ignition cover, verify timing, and check for crankshaft endplay. Oil change, check valves, adjust tensioner, and then hit every nut and bolt. Am I missing anything?

Jack wrote: JakeB wrote:

testarossa wrote:

[/img]

You can see the round cam caps in this pic.

EDIT: when I say cam caps I mean the cam end plugs.

Yes the end plugs are the same for Z1 / KZ's right up to the J model. 81-83 ,I believe, have the metal covering on rubber plug, 83-84 GPZ are plain rubber and both are bolt through type.

Looking at the photo, I was initially thrown off by the MKll rocker gasket on a '73-78 style head.There's no casting underneath the gasket btween 1&2 & 3&4 exhaust side. BTW, 79 LTD's are a unique deal MKll engine covers but 15 tooth crank centrepin and Z1 style cases, not MKll.

79 LTD's up to a certain serial number were like that. From that number forward, they got MKII engine.

MKII engines are easy to spot because of the engine cases. In top photo, the fin behind the oil filler cap tower stops on top of the case. Standard KZ.

In the bottom photo, the fin extends right down to the case, behind the clucth. MKII. Those differences are easy to spot when looking at motors.

kzrider.com/forum/13-bike-related/375288...ii?limit=20&start=20

u could also try adding a carb cleaner to the gas. like seafoam.

Got home from the Scout's campout and the FedEx man had left me a present:






Not too bad for $150 plus shipping.

I still haven't made any progress with diagnosing my carb and vibration issues. On Friday, I did pop off the ignition cover as OMR suggested. I didn't see any discernible amount of endplay as the motor was revved. I also dragged out the timing light and verified that the timing advanced properly, which it does. I did notice that I had the incorrect advance curve selected according to Dyna's suggestions. Basically, I had selected a curve that only had 20* of advance with full timing at 2500, which they suggest for a 4 valve motor. The proper curve has 25* of advance with full timing at 3500. So new curve selected, and the idle got slower. I adjusted the idle and went for a ride with no change in either issue.

Good score on the cams.... you Texas bastard!

porchev914 wrote: Good score on the cams.... you Texas bastard!

All of the good ebay or CL scores have come where the seller made some kind of mistake. This is one of those cases. I bet he could have got $400 for these if he had just listed it right. Nowhere in the add did it say anything at all about brand or grind #. He simply listed them as .410" lift NOS camshafts. Not to mention, he had a BIN of only $150. You know I'm jumping on that deal.

I spend quite a bit of time looking for mis-spelled listings, stuff that doesn't have pictures on the search page, or stuff that the seller doesn't truly know what they have.

u could also try adding a carb cleaner to the gas. like seafoam.
i think u may still have a blockage somewhere.
when u get that cleared up u may want to resync. just in case the last sync was fooled by the blockage.