Looking At Hotter Cams-What's Needed???

Hey Gang - The tach gear on my exhaust cam decided to chew some teeth on the cam gear last night. Luckily it happened only a couple of hundred feet away from my driveway and the engine didn't run this way for long as I shut it down.

I took a look under the cam cover and noticed the shattered teeth on the exhaust camshaft. All of the tiny broken bits were in the head recess just underneath the gear area on the cam. I am confident that I got them all out with a magnet pick-up tool.

Since I am going to need another exhaust cam I am considering picking up a set of hotter cams to really make the 810 breathe better.

So what is involved in matching up a set of hotter cams? What kind of stronger parts will I need? I already have stronger GPz springs in the head. Any other items or machining I should be keeping in mind?

Cheers-Colin Firth-Ontario Canada

Colin, my first thought would be to look for a set of cams from either a KZ 750 E series or from a KZ 750 H series. These will allow you to retain your stock tach setup and from what I understand they are a little hotter than what the 650's came with. You will have to use the 650 cam sprockets due to the different type of cam chain used on the 750's after 1980. Shouldn't be too hard to find nor too expensive on Ebay.

i don't think you will gain/feel much difference by putting in stock 750 cams,look into sum hotter cams from APE or schnitz just to name a few,tell them what you have done to your engine and what type of riding you do most,im sure they can/will recomend sum drop in cams that will make a BIG difference.

Hey Gringo - I am already running the 1980 Kz750/4 cams which are better for hp than the stock 650 cams.

Since I am going to have to swap out the 750 exhaust cam because of the sheared teeth on the tack drive, I figure I might as well go the last few feet on the 810 upgrade and go with the hotter aftermarket cams that have the tach drive already machined into the exhaust camshaft.

Just curious as to what other upgrades I might have to make such as trimming valves or machining the head for any clearance issues. I already put in stronger Gpz springs when I did the head last season.

Thanks-Cheers-Colin Firth-Ontario Canada

I have discussed this with the tech at APE allready since Im wanting to go as big as possible (and stay streetable) they told me to go with the web grind #110 which is .395 lift (forget duration, but its easy to find in the webcam site) and I would need to use the vs900k valve springs for the much ligher lift. Im not sure how the gpz springs compare to these aftermarket springs, but the springs from ape are only $60 or so.
I asked about the 189 grind (.400 lift) but they said it would be too much and would really kill the motor in the low end. APE can "make" your cams into the web grind, so if you kept your 650 cams you could send those in and you would retain the tach drive. APE also quoted me a little less that the web cam site for price aswell. Im sure if you email the tech department they can tell you exactly what you need to do. make sure you include the milled head and bigger valves in your specs

hey reborn im curious what are the specs for a stock 650 cam and what are the specs for the 750 cams you already used?, thankyou