[WFO-KZ]

"Then pull remove the idle screw"??? Not sure I understand this part.
Nice boots tho.
I agree with your method of cleaning major heavy dirt and grime off outside of carbs first and then dunk in heated ultrasonic bath with a Simple Green solution. I use the stuff that says safe for all metals.

 

[John Mull]

There is a hand screw to set idle speed at 1200 rpm with your thumb. Gray plastic top. That guy is by the in the way of one of #3 carb cap screw to get a screw driver in there. Have to pull it off the get here. Picture show it out near the cable guide.

 

[WFO-KZ]

Gotcha! Item 27 on the list.

Kawasaki Motorcycle 1978 OEM Parts Diagram for Carburetor Assy | Partzilla.com

Buy OEM Parts for Kawasaki Motorcycle 1978 Carburetor Assy Diagram

www.partzilla.com

 

[John Mull]

I have completed the applying of the carb kit. Would you let me know if you think I over did it.

Bike has Pods from a local guy 2 years ago but was using standard jets #90 main, #50 slow. Lower slow was a #10. The needle pin was set to the middle #3 spot. Fuel mix screw was all over the place with the 4 cyl. cyl1-1 7/8, clyl2-1 5/8, cyl3-1 1/4, cyl4-1 1/2. From the looks of things, I don't think anyone was in this carb before. It is clean now.

Still has pods, changed the main to #97.5. My kit didn't have slow jets that worked, so still #50 and #10 lower. The needle was raised by placing the clip down 1 spot #4. I also change the spark plugs to NKG B7ES. My kit did have a fuel mix and I set all 4 cyl to 1 1/4.

The complaint was it bogged down in the middle range. The change to the needle up one spot was to improve the off throttle. The lean condition, I thought it had is the reason I used #97.5. Idle was fine before I messed with this carb. Kit didn't have a fuel bowl needles, so that was reused.

Question I have......too many changes.....just right....? Thanks for the comments.

 

[WFO-KZ]

The proof is in the pudding. Give her a go and let us know how it performs.

 

[John Mull]

I will do a final post once running. Last night it was -9 here in Chicago. Snow piled up everywhere. Too cold to even put on the intake boots or new fuel lines.

I have a Gunson Colortune tool to measure fuel to air mix while running. I can't say it works any better than an experience guy listening to the rpm drop opening/closing. Not skilled enough either way for me.

Carb ready to go back in when the temps warm up a little. Always nervous until you hear the engine run again.

 

[John Mull]

Anyone have an approach to adjusting valves on this bike?

My settings are off, but I have to purchase different shims. No clue what is inside currently. It does take some effort to pull out the old shims and see what I have. Then order new ones if I can't mix/match better. A lot harder to adjust these than other bikes where you just reset the screw and lock nut.

1978 KZ650B2 with a B2A VM22 carb. I seem some 2.20 and all kinds. What to do with extras, throw them out?

Valve gap tests.
Cyl 1 In .10 Out .10
Cyl2 In .06 Out .10
Cyl3 In .10 Out .13
Cyl4. In .09. Out .13

Spec says .15 for both In and out.

 

[John Mull]

I got a suggestion from another KZ650 owner that I should have put in "air correctors" instead of changing jets or raising the needle for these pods. The example I have on ebay is not for a VM22 carb though.

Do you think I wasted my time changing jets and should have used air correctors?

Air corrector jet kit.Kawasaki Z1,Z650,Z900,Z1000,Z1R.MK2, MIKUNI.LEDAR.PODS.K&N | eBay

Enough for ONE (1) four cylinder bank of Mikuni VM24 / VM26 or VM28mm carburettors. You will need to internally thread the needle jet air bleed in the mouth of each carb 8mm deep with an m5 x 0.8mm tap ( TAP NOT INCLUDED ).

www.ebay.com

Picture is of a VM24 and mine is a VM22, but those shiny parts are something called an Air Corrector.

 

[WFO-KZ]

ColorTune device looks awesome. Post pictures or video of its use on your bike if you can please.

Yeah, shims can be a pain especially if they are shim under bucket which requires camshaft removal. Dealers have it easier as they have a stock of all sizes of shims on hand, so they don't have to attempt "mix and match" games or wait for new shims to arrive. On the plus side, shims don't require adjustment as often as the old rocker arm-setscrew designs and it eliminates the disasters that can occur if a rocker arm locknut comes loose.

Some dealers will take your old shims on trade, sometimes for an even swap, other times for a few $$. If you keep accurate records then next time you adjust your valves you will be able to calculate in advance, the shim sizes you need.

I have no experience with "air correctors".

 

[John Mull]

Yes, I will post the Gunson video once I get to it. I have to purchase an attachment to refit the spark plug opening. Plug size on a KZ650 is larger than my previous restore of a 1972 Honda CB350F.

 

[John Mull]

I have run into problems with my Gunsons tool. It is a 12mm thread and my KZ650 is 14mm spark plug size. I don't see an adaptor from 12mm to 14mm, just the other direction. Bummer.

Carbs reinstalled. Previous owner's INA pods used because the Moxi new ones seem to cover the intake holes. Chicago temps cold 20 degrees in the garage/shop. New rubber intake boots. I replaced the Phillips JIS screws with Alan headed screws. Much easier to tighten. Used zip-ties to support the back end of the carbs since it is missing the standard air box.

Engine started with a little kick starting and work. No gas leaks out the bowls. Gravity fed fuel line. Choke full on at first, then backed down part way. Engine popped a lot. Had a hard time idling when warmed up some with out stopping. After running at 4k rpm (where I could get it) and going through a 1/2 pint of fuel, I used some Mystery oil deluted through the system. Sometimes I use Sea Foam just to "oil" it up some. I knew it had a lot of wd40 inside. Then I go back to regular 87 fuel. Popping stopped/slowed down some. I think cyl4 is too lean. I controlled throttle with the choke lever. If I tried the throttle grip twist, the engine bogged down regardless how slow I turned the throttle.

Engine got hot without much air flow. cyl1-250, cyl2-250, cyl3-300, cyl4-600. Seeing that, I shut it off and check plugs. Plugs 1 and 2 looked pretty good. Not carboned up and a little wet on both. Cyl3 a bit lean (maybe perfect) with the to ground electron wire white on the tip. Rim was white dry. Cyl4 was white across the full top of the ground electron wire. White and dry on the rim. Sorry no pictures.

Think cyl4 was lean (temp high, white on full tip), I turned out the fuel mix screw. "Out" to me is turning-to-the-left. It is a pointy fuel screw close to the engine. So I think that will put in more fuel. Anyone....correct? It was originally 1 1/4, it is now 1 1/2 turns out. I did not change cyl3. Screwdriver doesn't fit under the carb. I have an old one to cut up.

Picture added. The fuel mix screw I turned out is the top one. I turned it to the left 1/4 turn. So I have cyl 1 thru 3 at 1 1/4 and cyl4 at 1 1/2 turns out. Hope that is correct to make cyl4 richer.

With the throttle grip bogging down worse, I could change back the main jet from 97.5 to #90 and see if that helps. Another idea is change the needle from position #4 back to original #3 spot. I will replace plugs and work on the the fuel mix for the next few tries.

Ideas welcome.

 

[John Mull]

New run today. It seems my Cyl4 problems was with the boot vacuum test tube caps. I replaced all the rubber caps and today's run look good. Cyl temperatures the same across all cyl at 425 degrees with a 10 min run.

I am having trouble with the choke lever. I have to leave the choke ON 1/8 up to get an idle. I would try to balance the thumb screw on the idle screw to keep it running at 2k RPM and gently turn down the choke. Engine kept dieing,

Any ideas on where to look? I have good throttle response when the engine is around 3k RPM or higher. It doesn't bog down. I did not change the needle or the main jet, this test. Left them as #4 needle position and 97.5 main jet. I think I am good, if I can get the idle stable.

Thanks for the ideas.

 

[WFO-KZ]

If all jets are still clean, then you may have to go up one size on the pilot jet.

If your adjusting screw is close to the airbox then it is a pilot air screw and turning it out will make the mixture leaner.
You probably need the mixture to be richer so try turning all of them in, no more than 1/4 turn at a time. Try the bike after each adjustment. If that does not work, try going leaner and if that does not work, go up one size on the pilot jet and then repeat the above process.

Welcome to the difficult world of trying to tune a carb for pods.

 

[John Mull]

Looks like I get it idling again. I opened up the fuel mix screw 1/8 and the choke now can close.

 

[WFO-KZ]

Great news that it now idles!

Can you send a photo of the adjustment screw? Some of these carbs came with an air-mix screw, some came with fuel-mix screw and some came with both! The ones with both had the fuel-mix adjuster on the bottom of the carb. I don't think yours has that.

 

[John Mull]

Here is the bowl bottom. The fuel mix screw for a VM22 style is at the top exposed for adjusting while installed. The VM22 is not very common. Ours is a 1978 KZ650 manufactured for US market Jan 1978. The pilot screws are one on top of another with a pilot jet and then a secondary idle jet.

 

[WFO-KZ]

Well Kawi sure made it confusing with all those different carb versions. Anyway, nice to know you have it sorted for idle.
How is throttle response from idle thru to full throttle?

 

[John Mull]

Right now, the throttle response is bogging worst than before I started the carb cleaning and adjusting the needle to position #4. My carb kit had a #97.5 which I used and their needle. I also used the fuel mix needle. Idle jets were unusable from the kit.

So now I have a dilemma. Various guys said change the needle position and other said up the main jet. To back off the changes, not sure if I go back to the original needle and reset the position or reset the needle with the #3 original position. Also change back the main jet to #90.

So I am thinking about it. Snow bound, can't go out and ride. Suggestions welcome.

It comes of throttle if I move it gently. I get it up to 5K RPM and it bogs. Plugs show me that I am ok on excessive fuel but it feels like it.

 

[WFO-KZ]

My apologies if this has been discussed before in this thread but did you get your jets from a reliable source? Word has it that knock off jets from China suck. Some folks advise to buy only OEM jets and needles. I have no direct experience, just going by what others have said.

 

[John Mull]

Carb kits that are not EOM often don't fit as well. The problem comes down to what is available at reasonable cost. My kit was $5 per carb or $25 total. The gaskets were nice quality. With all the variety of KZ650 bikes and carb styles, mine partially fit. I got what I paid for in this case. Let me know what a complete carb kit would have cost EOM, if one is available from Kawasaki. I would like to compare costs.

Regarding charts and images, they are screen shots of other KZ650 group. The KZRider and Facebook KZ650 group. Not sure where they were sourced. My Cylmer manual for KZ650 had some items described well, but not on the carb. No markings on my bike to say the exact model, but from the design, it is a VM22 and not a VM24 more popular carb.