KZ650 Sooty Plug

Ok the electrical issues seem resolved so took her out today with B8's fitted as the plugs looked a bit hot with the 7's.....number 1 plug fouled but others seemed OK number 2 was a bit rich ? see picture below.
Dropped the 8's back in and repeated the same 6-8 mile circuit and all clear but again they look lean to me ?
I fitted larger pilot jets about 2 years ago to try and help her warm up quicker as she was taking like 10 minutes before I could actually pull away.
Question would the original 15's help her over the 17.5 currently fitted, or should I leave her as she is and alter the air screw to richen her up slightly?

 

#4 looks like oil fouling

If you have a mostly stock 650 engine then B7ES (R) should be fitted, they are the correct heat range.

You would only need B8's if you had a very worked on engine (head/cams/big bore etc)

In your avatar pic it looks like that bike has a stock air box and stock dual exhaust, if that is the case you should use #15 pilot and #102 main jet.

#17.5 pilot is too rich for a stock engine configuration, I have had some that used pipe/pods with a #15 pilot with no issues.

Many thanks if I can face pulling the carbs I’ll drop the #15 back in.....but looking at the plug colour they do seem OK now.

If your hands are small enough can take the float bowls off with the carbs attached to the head and air box without removing them.

I do this all the time, this was pointed out to me by 650ed many years ago and he looked to be larger than myself. I believe he posted about it on here, he used a tiny 1/4" ratchet.

I eventually found it easier to use a tiny 1/4" drive flex breaker bar with a 1/4" socket to hold a JIS bit to loosen/tighten the screws. Then faster to remove the screws by hand with the bar removed and a adapter on the socket.

This method has been proved faster than removing the air box and carbs. Unfortunately it takes practice, patience, and smaller hands (for some it might be impossible)

I may have some pics somewhere.

Found some pictures of float bowls removed with carbs on engine with air box installed but they are not VM24's. These are Mikuni 33 flat slides off a GSXR750R on my 831cc 650 engine street bike.





These carbs may even hang down lower than VM24's (not sure) These are a bit trickier to service as the bowls are joined by a fuel pipe, so you need to take both off in one go. The stock carbs are much easier to service in this fashion unless they have accelerator pumps, not sure as I don't have 650 pumper carbs.

I put a rag down so the screws are easy to find and it soaks up any gas dripped. I always have a fan on to blow out the fumes

I have tried this with the bike on my lift stand and it it very awkward, its actually easier when the bike is on the center stand and I am sitting on the garage floor. It seems the angle is better the lower you are, and you can see the screw heads better. The lift stand gets in the way and my back gets sore!

Many thanks I did try the outer bowl but to be honest the fuel pipes were in the way, if I find the plugs still fouling I’ll whip the carbs off. It’s not over difficult and my rubbers are pretty supple.

After a few times on and off, you'll develop a routine for removing the carbs - everything on each side done at the same time, for example, and knowing the best way out for the rack.  Then the job goes smoothly. 

How fresh is the fuel in the bike?

Fuel was fresh as a daisy