79 kz650

Looking to get perfomance options. I've read up that this bike is 62 horse stock, I'd like to pull 85-90 horse out of it, is it possible?? Maybe people can send me links of where to get cams, exhaust options, stroker cranks, ignition systems, tweaks for the carbs anything to develope more horsepower and to keep reliability at the same time. Thanks everyone, and enjoy the ride.

1980 KZ750 cylinder block with 810 kit, the 810 big bore kit is available from Wiseco

Send your head to be ported at flowbenchtech.com

Check MegaCycle for cams.

BS34 carbs should work, although I would use a MegaSquirt and fuel inject it (details available Here

Exhaust, as far as I know you are limited to either Mac or Vance and Hines if you want new, otherwise shop eBay.

That ought to get you there

lots of cubic inches is gonna be the easiest way to make reliable horsepower 750 cylinder and an 810 kit with a mild head ,small set of cams and a set of 29s with a header should keep you entertained without requiring constant upkeep;)

Or you could bolt in a stock 83-85 GPz750 motor, it's rated at 85 hp.

GPz750 Turbo motor would work also, 115 hp stock IIRC

steell wrote:

1980 KZ750 cylinder block with 810 kit, the 810 big bore kit is available from Wiseco

Send your head to be ported at flowbenchtech.com

Check MegaCycle for cams.

BS34 carbs should work, although I would use a MegaSquirt and fuel inject it (details available Here

Exhaust, as far as I know you are limited to either Mac or Vance and Hines if you want new, otherwise shop eBay.

That ought to get you there

I like the idea of punching it out, although new cylinder block seems like alot of work. If I do the 750 block, can I re-use my 650 head?? Will I need larger valves?? What would you recommend for cam specs?? What kind of power increase could I expect by just punching out my 650 to the 700 kit?? Maybe use some cams on the 650?? Then re-tune the carbs?? Will my factory carbs be ok on the punched out 650?? I really like the bike, but it really needs just a little bit more. Thanks for all of the useful information guys.

If you want "just a little bit more" out of it without doing major mods/conversions and still want to keep it streetable, here's what I plan on doing with my 650 eventually:

DYNA II electronic ignition (already installed)
Wiseco Big Bore kit (currently gathering dust sitting on the workbench in my garage)
GPz750 cams (block off tach cable opening in head and install electronic tach)
Larger (VM29's perhaps) carbs.
Light porting and larger (GPz750?) valves


All of these "upgrades" have either been performed individually or combined on other members bikes here with good results, so I can trust they will work well on my bike too.

Post edited by: RetroRiceRocketRider, at: 2007/04/15 12:23

RetroRiceRocketRider wrote:

If you want "just a little bit more" out of it without doing major mods/conversions and still want to keep it streetable, here's what I plan on doing with my 650 eventually:

DYNA II electronic ignition (already installed)
Wiseco Big Bore kit (currently gathering dust sitting on the workbench in my garage)
GPz750 cams (block off tach cable opening in head and install electronic tach)
Larger (VM29's perhaps) carbs.
Light porting and larger (GPz750?) valves


All of these "upgrades" have either been performed individually or combined on other members bikes here with good results, so I can trust they will work well on my bike too.<br><br>Post edited by: RetroRiceRocketRider, at: 2007/04/15 12:23

I don't mind punching out the motor, that's not a problem. I just need a little more info before I tear into the bike. I'd like to know how much power each mod provides. I have a feeling i'm going to end up doing this through trial and error like my Banshee. One more question I'd like to ask. My brother-in-law has an 83 kz550. When he bought it it had k&n individual air filters on it. Unfortunatly the trans breather was pissing oil onto the rear tire, causing it to become un-safe to ride after. He ended up putting the stock airbox back on. IS there a way to block that off so I can actually run individual air filters on my 650 without the oil issue?? I found these for the valve cover breathers, www.kzzone.com/billet.html but is there anything availible for the trans??

Enjoy the ride.
-Paul

I wouldn't suggest blocking that fitting off since it's desgined to vent the crankcase.

K&N offers VENT FILTERS for that application, and most auto parts stores sell similar ones for around $10~$15.


It sounds like your buddy with the KZ550 either didn't have one of these vent filters mounted, and/or overfilled the engine with oil.

RetroRiceRocketRider wrote:

I wouldn't suggest blocking that fitting off since it's desgined to vent the crankcase.

K&N offers VENT FILTERS for that application, and most auto parts stores sell similar ones for around $10~$15.

It sounds like your buddy with the KZ550 either didn't have one of these vent filters mounted, and/or overfilled the engine with oil.

So with the vent filter I can safly remove the air box? How about the breathers on top of the valvecovers?? They seem like they're just there for emissions. Since I'm in CT anything over 25 years old is emissions exempt.

Do a search in the archives and the current board and you will find dozens of threads about the 650 to 750/810's. It's a pretty popular project.

I have a 79 650SR in the garage right now, with a 83 GPz750 motor in it, it's my Nephew's bike.

A member in Australia has a KZ650 that is now a 810, and has MegaSquirt EFI on it.

If the breather is spitting a lot of oil out, then ther's something wrong with the motor.

Normally you can just fit an elbow on it and connect a hose to the ground. Don't block it off! It is the vent for the crankcase, if you block it, you'll blow oil out of all the seals in the motor.

loudhvx wrote:

If the breather is spitting a lot of oil out, then ther's something wrong with the motor.

Normally you can just fit an elbow on it and connect a hose to the ground. Don't block it off! It is the vent for the crankcase, if you block it, you'll blow oil out of all the seals in the motor.

I'm just going to go with the filters. I found some on ebay. Thanks for all of the useful information guys. I'll keep ya'all updated as I go along. The bike's been crashed twice so there's other things that need to be replaced first.