Drag strip trip.

Mark that motor's about the same as my gpz motor.
738 cc.
head wise I did this cut out stock
intake 650 vs gpz head.

Not sure on your cam number's but we're probably close.

No reason why at the factory 87 hp and 620 lbs suited
I can't run mid 12's other then this thing can't breath
on the little carb's but I'm fixxin that shit.
The 29's cleaned up nice.

Injected wrote:

Attachment earlytimingslip.jpg not found

Let me up date this.
Last weekend went to the track with the new carbs
and played with the bike.
Best pass was.
60 ft. 1.8449 (blowin the tire off)
330 ft. 5.0374
1/8 mile 7.8142 AT 88.08
1/4 MILE 12.38 AT 102.83.

Nice improvement

Looks like a baffle of some sort in the pipe in the one photo. Yank it out.

Cam wise....if you're keeping compression moderate, duration should follow. Megacycle 471-10. If you're going full on race compression, Megacycle 471-20, for example are a couple of good grinds.

Least expensive way is 83 Gpz 750 cams as a drop in with OEM Pistons.

Larry the motors an 83 gpz so I have those cam already.
As for the baffle its just the end plate off a baffle
not a full baffle.
Will be doing a sidewinder off a 900 modded to fit.

Commpression whys I plan on taking about 020 off the head,
degree the cams with a mild port job.

I think if I can get it to stop spinin the tire
through the 60 ft. it should go 12.20s or better
just need to work on the tune and set up some more.

Awesome! Huge improvement. Cool to see. :evil:

Looks like fun.
did u try taking some air out of the tire?

At about 20 lbs. there ain't much more to take out.
The 130 tire on the stock 2.15" rim's
sucked in and not using all the tread.

Calling Buchanan's spoke and rim in the morning
to see about a 3 1/2" maybe 4" black anodized alum.
rim and spoke set.
With the gpz swing arm and some offset sprockets
I can fit a five inch slick easily and 7" stuffed.

zukdave wrote: Larry the motors an 83 gpz so I have those cam already.
As for the baffle its just the end plate off a baffle
not a full baffle.
Will be doing a sidewinder off a 900 modded to fit.

Commpression whys I plan on taking about 020 off the head,
degree the cams with a mild port job.

I think if I can get it to stop spinin the tire
through the 60 ft. it should go 12.20s or better
just need to work on the tune and set up some more.

Those heads are pretty good stock for an 810 motor

So you're saying don't mill the head and wait till I do the 810
and let the bigger bore rise the compression ?

Another question you think going to a larger dia.
header tube will help or hurt the power ?
Nobody makes a sidewinder to fit so was thinking a KZ900-1000
pipe cut to fit as a step header set up.

Bigger bore in itself wont do much compression wise,but an 810 piston that matches the gpz combustion chamber would definately help.
Id try a Skinnier rear tire to flatten contact patch if it were me anyway

zukdave wrote: At about 20 lbs. there ain't much more to take out.
The 130 tire on the stock 2.15" rim's
sucked in and not using all the tread.

Calling Buchanan's spoke and rim in the morning
to see about a 3 1/2" maybe 4" black anodized alum.
rim and spoke set.
With the gpz swing arm and some offset sprockets
I can fit a five inch slick easily and 7" stuffed.

Is thew gpz 750 arm that much wider?
I dont remember the 81-82 arm with dual shocks being any wider than stock 900-1000 arm,a 3" rim and a 130 tire is usually about it in a stock 900/1000 arm anyway.

+1 - if so...maybe I need to look at swapping one of those arms over...