Testarossa's 78 KZ1000 Fighter Build

Which brand chain did you use?

Unless you've got those (as Larry puts it) "stump pulling cams" I don't see why it would stretch that much.

testarossa wrote:

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?

Yes the cam chain will stretch just like a drive chain for the 1st 1000 miles or 2. depends on the severity of your wrist movements. at least mine did. but my wrist does have a habit of twisting on me. just check it occasional until u dont get a change anymore. then u can check it every 5000 or so.

Good info, thanks!

And Mark beat me to that comment.:laugh: Yeah, they stretch just like any chain will when new. I'm slow today. Just finished moving what was left at girlfriends house. Should be closing on that sale next couple weeks, that will be 1 less headache. Only took 2 yrs with the economy to get it done.

Something I was told a while back. Chime in if you have heard different, I dropped off a MK11 crank to a local nationally known dragbike racer who builds KZ motors for a living and I know the rods weren't in line. I have a index rod and checked it out. He was going to send it to Pearsons (I think) but Pearson told him that a crank out of aline by up to .040 was common and nothing to worry about unless you were building a top of the line motor. Sounds like a lot to me but I will venture to say that he knows more then I do about those things. Take it for what it's worth.

Pearson told me the same thing, not uncommon for a MK2 crank to be out. but he indexes them up when he does his thing before welding. He's got mine now, that man is busy which is a sign people come back for more.

I have heard nothing but good things about his work. I have one of his MK11 cranks myself. Do you have his number or web-site you could share?

John Pearson 1-937-839-9723 . He's backed up pretty good

The last two kz's I rode had all kinds of noise, cam chain, vibration, I think its more along the age and design of the bike than anything else.

Patton wrote: 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.

I think that you are on to something here. I started poking around this afternoon when I got home and discovered one of the choke plunger levers had a missing set screw. So that choke enrichener never got opened when the choke was open. That explains why it seems tough to get it warmed up in the morning. I put some blue loctite on all of the set screws and made sure that they were tight.

Went for a short ride and it seems a little better. AFR is still dipping into the 10.5:1 range, but not getting down to 10:1 like before. Now when I got home, I got out my laser thermometer thing. After the bike was fully warmed and idling with the aggregate AFR at 14:1 I started taking header temps about 3" from the head. #1,#3, and #4 are all 500*F +/-25*, but #2 is at 300*F. So I decided to fiddle with that pilot screw until I got it even with the other three. I had to back it out almost a full turn (richer) to get it to 500*. Seems that I may have a slight clog in the pilot circuit on #2. Now since I have been tuning those pilot screws based on getting an aggregate AFR about 14:1, I have compensated for one extremely lean cylinder by richening the aggregate mixture too rich. I went for another ride after tuning that one screw and now my stumble is back in full force. AFR now reaching down to 9:1. When I got back to the house, it's idling with the AFR in the 10.5:1 range.

I didn't have time to delve any further tonight. I guess that I need to see about getting that pilot circuit cleaned better. I'm betting that with #2 functioning properly, and the mixture adjusted back to 14:1 it should perform properly.

DoubleDub wrote: Which brand chain did you use?

Unless you've got those (as Larry puts it) "stump pulling cams" I don't see why it would stretch that much.

New cam chain is the recommended Tsubaki brand.

Cams are currently the Kawasaki issued units. Not sure that they could be considered stump pullers. Maybe I could weld 'em to the back of the old Massey to pull some stumps. :laugh:

testarossa wrote: ...header temps about 3" from the head. #1,#3, and #4 are all 500*F +/-25*, but #2 is at 300*F. So I decided to fiddle with that pilot screw until I got it even with the other three. I had to back it out almost a full turn (richer) to get it to 500*. Seems that I may have a slight clog in the pilot circuit on #2. Now since I have been tuning those pilot screws based on getting an aggregate AFR about 14:1, I have compensated for one extremely lean cylinder by richening the aggregate mixture too rich. I went for another ride after tuning that one screw and now my stumble is back in full force...need to see about getting that pilot circuit cleaned better. I'm betting that with #2 functioning properly, and the mixture adjusted back to 14:1 it should perform properly.

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!