Cams for stock kz900

I would like to put some performance cams in a stock 900 motor. I have Mikuni flat slide carbs and 4/1 header,the bike runs great,but would love a little more horsepower. Don't know where to start, any advice would be greatly appreciated.

Check out JOE HOOPER at PITSTOP PERFORMANCE for some of their PSP cams.
They are proven ANDREWS profiles.
Give them a call and he will advise you on the best combination for your needs.

:huh: you are sorta limited to cam selection when using stock pistons and valve springs. you can use web 118 grind (.365 lift) for stock engines $410........ add another $55 for slotted cam sprockets as any cam you install needs degreeing. :huh: or get a used set of GPZ 1100 cams........ better spending of your money would be to do a 1015 kit with more compression in your 903 cylinder or good stock 1015cc block and pistons ....IMO :pinch:

All ears on this one. Not to hi-jack the thread, but does Anyone else with any more information on this topic? I thought of taking my 900 and honing/re-ringing and throwing a decent set of cams in it. Looking for what parts I would be looking for other than the obvious like Rings, cams, and a valve job.

zed1015 wrote: Check out JOE HOOPER at PITSTOP PERFORMANCE for some of their PSP cams.
They are proven ANDREWS profiles.
Give them a call and he will advise you on the best combination for your needs.

I sent him my last KZ900 head and he fixed me up with a valve job and guides. This bike has his MTC pistons(10.5) in it.

jp-15 wrote: All ears on this one. Not to hi-jack the thread, but does Anyone else with any more information on this topic? I thought of taking my 900 and honing/re-ringing and throwing a decent set of cams in it. Looking for what parts I would be looking for other than the obvious like Rings, cams, and a valve job.

your wanting to use the stock 903 piston, right.......

You are LIMITED to drop in cams web makes a drop in for stock engines as well as cammotion....(most are less than .390 lift)and still use good stock valve springs as the valve pockets on the oem 903 pistons are not deep enough, nor is the cast piston able to be machined for larger valve pockets as the dome will end up being too thin.....
cost: web 118 grind for stock engines $410 cam set, adj cam sprockets $48....if you need .500 lift valve springs :S they are $110 a set :huh: 8 valve stem seals $25

:huh: why not spend your money on an upgrade of a good used stock 1015 c.c cylinder.......you can usually find a cylinder with pistons for less than a $100 on flea bay .....no replacement for displacement :whistle: 112 c.c. more for your engine which equals more h.p. and torque....more benefit than a bigger cam change as bigger cams usually sacrifice low end and move the engines power band up the scale...Imo just saying....... :dry:

I'd like to keep the bike a 900. Everybody goes bigger. I like to be different I guess. I'm trying to not get too carried away. If I was too switch to a NON-stock piston at the same bore, would I be less limited? Do they make a good forged piston I can put in? Thanks for the info! As of now I'm talking....

Forged piston set at 903 cc displacement
Gasket set
Cams
Adj. Cam sprockets
Valve Job with new guides/seals

What else would be good to replace while I'm in there? I will also be looking for some larger carbs, as its only got 26's on it now.

I would also like to up the compression if I'm changing pistons. (pump gas) would I be better off milling the head, or does someone make the piston I'm looking for?

timing chain and idler gears are very important in keeping these old bikes happy.

leon

jp-15 wrote: I'd like to keep the bike a 900. Everybody goes bigger. I like to be different I guess. I'm trying to not get too carried away. If I was too switch to a NON-stock piston at the same bore, would I be less limited? Do they make a good forged piston I can put in? Thanks for the info! As of now I'm talking....

Forged piston set at 903 cc displacement
Gasket set
Cams
Adj. Cam sprockets
Valve Job with new guides/seals

What else would be good to replace while I'm in there? I will also be looking for some larger carbs, as its only got 26's on it now.

wiseco and mtc are forged and no longer make any stock bore 10:25 903 piston kits, wiseco's smallest kit is 1015 c.c.,MTC smallest is 1075 c.c......... :S possibly J&E might make a set. way more expensive.... :pinch: depends on how bad you want a 903...... :dry:

531blackbanshee wrote: timing chain and idler gears are very important in keeping these old bikes happy.

leon

like Leon said....... :dry:

Can the 903 cylinders be bored to 1015? Or do I have to buy a while new cylinder?