1980 kz 650 f1 carb

Ok pilot circuit which is plugged somewhere so iv tryed to clean them six times still well not run when you het the troudle I was told that on this bike there are no pilot screws only air screws I,v taken out all the jets and cleaned everything with a wire and air and carb cleaner if you know a hole that most pepole miss I can use all the help I can get.Thanks,lance

Cleaning carbs is not that hard, you need to spray carb cleaner into EVERY passage you see. It should come out some where else, and then spray it backwards through the passage. Compressed air is nice too after spraying. What kind of exhaust and intake are you running on the F1? What main jets, pilot jets, clips, etc are in those carbs? A little more information goes a long way. More than happy to help out a fellow F1 owner but need some more info...

I tore it all down to try and clean it this time. Here is what I have,It's a Mikuni carb, the inside 1 and 1/16"inside the front and the back inside is 1 and 3/8".
The Pilots are 15 The main jets are 97.5 the air screws are at 1and1/2out The needles have only one notch on them
they have a number on them it's E15CL30 The bike has stock
air box {not hooked up] and stock pipes I have put on coils from a 81 kz650 and did the coil mod on it.It starts
right up and you can ride at 3/4 choke.I have put on new carb boots,put it in shop to have the chain tensioner fixed
and check the valve's They are good. I hope this help's

Thank's for your time
Lance

fireglass wrote:

The bike has stock air box {not hooked up] and stock pipes. Thank's for your time Lance

Everything sounds good, thing that bothers me is the "unhooked" air box. Running without airbox and stock pipes is like having pods. You will be running way lean (especially with 97.5's) Are the carb to box connectors missing? When you remove carbs and look down air box side of carbs, does accelerator pump squirt fuel into each carb when linkage turned? Pump was installed to compensate for lean jetting for better throttle response. With factory lean jetting and no air box you may have a very lean condition!

Thank you for all the good words,the air box,s is unhooked because of trying to get the bike to run. I see that 97.5
mains are for racing could they and the air box be why it dies when you hit the throttle ? I just want to ride in city driving so what main's should I use and well I have to change the needle's too? Also I'm assuming they are vm
28's.kawasaki made carbs with just a Air screw and one with Air
screw and pilot screw how can I know for sure these are not missing pilot screws? Lance

Your carbs are VM24s most likely. Measure the inside of the carb bore near the throttle slide on the engine side: it should be 24mm. The measurements you took are of the openings & really not much use. You should be able to use a main jet in the 92.5 to 102.5 range. The stock size is probably on the lean side (to meet epa regs of the day). WG has stated that 102.5s should work fine; however, I know of one 650 owner who says they cause a stumble or something at certain rpms. I'd guess the 97.5s will be okay. Connect the airbox properly w a good/clean filter instlled, then give it a go.

fireglass wrote:

Thank you for all the good words,the air box,s is unhooked because of trying to get the bike to run. I see that 97.5
mains are for racing could they and the air box be why it dies when you hit the throttle ? I just want to ride in city driving so what main's should I use and well I have to change the needle's too? Also I'm assuming they are vm
28's.kawasaki made carbs with just a Air screw and one with Air
screw and pilot screw how can I know for sure these are not missing pilot screws? Lance

The 97.5's would be the stock (not racing) jet size for a '80 F1. Sounds like you have a stock set of VM24's. If they are the factory carbs they will have the "air" screw on the side of the carbs at about a 45* angle. Two turns out is a good starting point. A pilot screw would come straight up from the bottom by the fuel bowel. My F1 has a spot under carbs where pilot screw "used" to be.

If carb parts are clean, sounds like you have a fuel starvation problem. Make sure fuel flows freely from tank, how are float bowel levels? Too low will cause major lean condition.