650 hop-up questions

all right, since i have my 650 running so good, i guess it only resonable that i take it apart anyway its a 78'650B all stock, runs extremely well.
things i want are:
1. stock appearing, ie. exhaust, airbox, engine
2. a bit more poke
so...i have a 85' GPZ750 engine. from what i hear the 85' camshafts are the ones to use, but IIRC the GPZ had bigger valves, so what, if any, are the draw backs of putting the GPZ head on the 650? i thought of putting the gpz engine into the kz, but i just like the look of the KZ engine and would rather not lose the kick start, though of putting the whole top end on the 650, but the cylinder block will not fit without machining right.
also since i am also very cheap the 810 kit is out, just looking for some ideas on what i should do, or what you would do in my shoes.
OR...if anyone has a titled 650 frame within a few hours of Milwaukee i have enough parts to put a bike together.

You cant put the gpz head on your bike, as far as I know the cam chain stuff wont mate up, you need the roller stuff. The only thing you can do is the cams, but then you lose your tach and have to get an electric one. You could also get a performance valve job, dont knwo how much that would help.

Your not going to get much more "poke" with stock exhaust, air box, etc. You could add KZ750 cams or head (larger valves) which might add a little but would not see much improvement with stock exhaust. You could also install a complete KZ750 motor which would do the trick. I understand that you want stock appearing but a 4-1 pipe really wakes up the 650 and does not have to be loud. I have a Kerker with a K&N (stock air box) with minor jetting and my bike pulls really hard.

yea i know the exhaust is a severe limitation, i have 4-1's hanging in the garage but the 4-2 stock is just too pretty to take off
i can live without the tach or fit an electric one inside an extra tach housing.
if you put a GPZ head on a 650 bottom doesn't it drop the compression a little bit cause of the combustion chamber design?
i beginning to think of plan B of just finding a frame and building another bike

Find a set of bigger carbs. I swapped to vm26 (replacing the stock vm24) carbs and there's a big world of difference. One of the guys over at www.kz650.info was just talking about how he put vm28s off his z1 onto his 650, sounds like it made quite a difference.

You can drop kz750 cams in, or the gpz cams, but you have to change the cam sprockets because of the cam chain design. Easy enough to do, just make sure you get the timing marks lined up correctly when you swap them.

Have your head machined. A little port and polish will do wonders.

The biggest change with exhaust is weight not exhaust flow, and putting these bikes on a diet is a quick way to wake up some horses.

i have the 34mm Mikuni's from the GPZ i was thinking about using. from what i read the GPZ airbox will fit in the KZ frame and look pretty stock, except puriest will clearly see the carbs are wrong, but i can live with that. also the stock cam gears should work with the GPZ cams and the just time it using the KZ marks right? i am leaning tword just putting the cams in and going from there. i have to do a valve adjustment this winter anyway, so i think i will take it in small steps

You wont be able to use your airbox with those carbs I dont think.

Maybe this exhaust?

www.z-power.co.uk/merchantmanager/produc..._33&products_id=1812

that look's like a very nice exhaust system. it makes anice change from what is usally available.

Yeah it looks very nice, stock look, I wonder if it performs as well as it looks.

i put a set of 26's off a 1000 and it livened it right up.

Timebomb,

did you rejet when you put the carbs on? What was the setup on the 1000 and on the 650?

if i remember right it was a long time ago, i tried it with the stock jetting but i leaned out the needle a couple of positions remember i was using a pipe and individual filters and a dyna ignition so it had better spark, more air flow as well.