TOPIC:

Also, I'm sorry to say, anything a shop says they did is subject to inspection and verification. "Trust but verify". Not that all shops are bad, but many use inexperienced help. Fuel level settings are one of things that takes practice in order to get consistently correct... same with sync.

I don't see what you are running in the way of jetting, but I do see you are running the stock air box with a stock or aftermarket filter???

Main Jet __________
Pilot Jet _________
Needle and clip setting _________
(Stock needle is non-adjustable and should have 4A10 Stamped on it)
Mixture Screw Turns Out _________
Float Height _________ (should be 27 mm with floats just touching the float needle)

Have you seen this?
www.factorypro.com/tech/tech_tuning_proc...igh_rpm_engines.html

Bench syncing is not as hard as it seems.
Vacuum syncing should be done whenever a valve adjustment is done where a shim needs replacing.
Have you checked your valve clearances?

thanks all. more progress (no test yet though)
I removed the carbs to double check things. and found a few issues that could be causing the problem.
the float level were not consistent. I set them all to 27.5mm
found that I had not replaced the pilots (I was sure I had!) and one of them was in really bad shape. I put 32s in since that is what came in the rebuild kit. (34s is what I pulled out...but they where all nasty)

currently:
120 mains
32 pilots
float: 27.5mm
fuel mixture screws: 3 turns out.
needles are stock and not adjustable (I really want adjustable needles!)

still in the process of re-installing the carbs and I will report as soon as I run the bike again.

a few notes:
- rebuild kit (and all jets) are from the K&L kit
- stock airbox, exhaust.
- I have NOT checked the valves yet (on the list)
- I live at 3400 feet so it may effect jetting.

loudhvx wrote: Also, I'm sorry to say, anything a shop says they did is subject to inspection and verification. "Trust but verify". Not that all shops are bad, but many use inexperienced help. Fuel level settings are one of things that takes practice in order to get consistently correct... same with sync.

I agree with this except the term "trust no one" is probably more fitting as far as repair shops are concerned. They may perform the desired "work", but more often than not are no more an expert on your bike. than you are, and are more likely to muddle through a repair in order to get paid, with no idea if they are doing things right.

Some are just plain dishonest. I dropped off my wife's sable at a large local tire chain here for them to "look at it" to determine why it had a front end shake. I knew it needed front tires, and figured that would be their diagnosis too.. but when I picked it up they told me that BOTH front CV joints were cut / torn and needed to be replaced, and for sure that was what was wrong with it. . except I had just replaced BOTH cv boots 2 weeks before that myself.
They could not explain how they were both now cut. Go figger! There was a hidden camera story on the news a short time after this plainly showing their technician cutting the boots in order to sell a $600.00 CV "shaft job" to customers. I cringe at handing my keys for anything, including my lawnmower, to anyone. I had bought tires from them in the past, and kind of trusted them.. until this.

khungerf wrote: thanks all. more progress (no test yet though)
I removed the carbs to double check things. and found a few issues that could be causing the problem.
the float level were not consistent. I set them all to 27.5mm
found that I had not replaced the pilots (I was sure I had!) and one of them was in really bad shape. I put 32s in since that is what came in the rebuild kit. (34s is what I pulled out...but they where all nasty)

currently:
120 mains
32 pilots
float: 27.5mm
fuel mixture screws: 3 turns out.
needles are stock and not adjustable (I really want adjustable needles!)

still in the process of re-installing the carbs and I will report as soon as I run the bike again.

a few notes:
- rebuild kit (and all jets) are from the K&L kit
- stock airbox, exhaust.
- I have NOT checked the valves yet (on the list)
- I live at 3400 feet so it may effect jetting.

These carbs were set lean from the factory, so a jet kit could help. I'd highly recommend taking it to a dyno for a base reading, and to have it tuned. Do a valve clearance check before you go any further, as you could have a tight valve. After a removing the carbs a couple of times, you'll probably go with Pod Filters. If you have the vacuum valve on top of the valve cover, removing that frees up a lot of space to access bolts.

CoreyClough wrote: These carbs were set lean from the factory, so a jet kit could help. I'd highly recommend taking it to a dyno for a base reading, and to have it tuned. Do a valve clearance check before you go any further, as you could have a tight valve. After a removing the carbs a couple of times, you'll probably go with Pod Filters. If you have the vacuum valve on top of the valve cover, removing that frees up a lot of space to access bolts.

Corey, maybe i am wrong but I thought you were one of the people who advised against PODS because of the difficult in tuning these carbs to them.
PODS would make it SOO much easier to get these carbs out.

If I stay with the airbox sounds like you are suggesting I go bigger on the mains and pilots? this will have to be seat of the pants as nobody here locally has a
Dyno.

Also, how did you plug the plates on the valve cover?

Thanks,
Lee

I really don't understand the concern about getting the carbs out and back in with the airbox in place. I've owned my 1977 KZ650-C1 since it was new (41+years) and I have only removed the carbs twice - once when I screwed up and let the bike sit for almost a year with fuel in the carbs so they gummed up and once to replace the carb holders that developed a leak. Each time I probably spent an extra 15 minutes or so fiddling with the carb to airbox connections. So roughly 30 minutes in 40 years - not a big deal. However, if I had replaced the airbox with pods I am positive I would have spent many hours and dollars trying to find the right combination of jetting etc. that would make the bike run as well as it does with the airbox. So why switch?

Regarding jetting - since your bike has the airbox why would you not simply use stock jetting? Ed

There are several methods of plugging the reed cage caps, some more redneck than others.
Many folks just hook the two together with a short rubber hose.
My KZ has threaded Allen head plugs in the passages.
The covers on my ZRX are plugged with 5/8 aluminum expansion(freeze) plugs.
Some folks run a hose from each cover to a y connector, then a single hose to the crankcase vent, thus creating a slight vacuum in the crankcase, freeing up about 0.0073 horsepower. I suppose you could run that hose to your pants instead of the crankcase vent if it has been a long dry spell for you

Progress! some things fixed... others not : )
got a chance to take the bike out today to our local facility to really give it a test.
idle seems good now. response from idle is good. top end pull is really good.
the midrange is anemic! so, it is just not there from 6k - 8.5k I am guessing lean. so... should I be looking at my pilot jets or needle??

I love my Pod Filters. I have to remove the carbs when I check valve clearances, in order to loosen the bolts on the cam chain tensioner. If I had the airbox on, it would be a pain. I commute 300 miles a week, so about every 3 months I check clearances. I have never had the airbox on my GPz since owning it back in 2003. The others I have had, never had the airbox either. I have heard nothing but problems from other GPz550 Owners removing and reinstalling their carbs with the stock air box. Might be easier on other bikes??? OK enough.

You can invest an air/fuel tuning set like the one I recommended on the other thread, but "plug chop" is not as accurate.

The reeds only ooperate under vacuum, so i you disconned the hose system, you can leave the reeds in there. I bought a set of Reed Covers from APE, and they look great. You can also look for a Non-California Valve Cover (Canada), and that doesn't have any of this system in it.
kzzone.com/billet.html



As for tuning, this will help.
www.factorypro.com/tech/carbtun.html
Unfortunately, I have never tuned the TK27 Carbs, using stock exhaust and/or stock airbox, only with Pods with 4-1. Is the stock pilot 32?
The CV30 uses a 32 pilot, but the TK27 uses a 34. I'd just get a Dynojet Stage 1/3 Jet Kit, and go from there.

In my signature is a free Base and Supplement Manual. Look at page 9-9 and that will give you the stock jetting. Even Dynojet's Kit recommends a 116 Main for the Stage 1 with the airbox, but then their kits use a different needle than stock.
www.dynojet.com/pdf/2112.pdf

CoreyClough wrote: ............. I have to remove the carbs when I check valve clearances, in order to loosen the bolts on the cam chain tensioner. .............

Egads! I'm glad I don't need to do that on my KZ650. Ed

Thanks Corey, it must have been something else I read.
stock pilot is 34, dyno jet kit does not appear to come with new pilots and my stock ones where in bad shape. I will have to order some 34.

but, you use yours as daily driver. with PODS no loss of low end usability?
if so.. then PODS and dynojet will be on order right away.

Thanks,