82 GPz 1100 carb conversion jetting question

[oldsport]

merged - see below

[oldsport]

My 1982 GPz1100 B2 had the FI replaced with BS34 "K" carbs and K&N pod air filters and the Mac 4 into 1 exhaust.

It's slow to warm up and seems to spits back through the carbs occasionally even after it's run for 15 min. or more. Eventually after maybe 8 or 10 miles, it seems to run without barking back much but doesn't quite have the mid-range I would expect.

I've got the carbs off for cleaning and repainting right now.

It has
125 main jets
needle in on the 3rd (middle) slot.

The book I have says the K had 122.5 main jets and the needle in the middle slot.

I'm thinking about raising the needle one notch when I put them back together.

Question - Does that seem like a reasonable thing to do?

P.S. (as it warns in the manual, I let both of the little ball bearings on the choke rod get away from me. Doh!)

[Andy the gringo]

I just did pretty much the same swap on my 84 GPZ1100 except I still have the stock exhaust and cheapie Emgo pods. I'm running lean with 37.5 pilots and 127.5 mains. I'm thinking of going to 135 mains on mine. I would think for your setup you would want to go with 40 pilots and 140 mains. Raising the needle a notch probably wouldn't hurt either you can always drop back down if it turns out to be too fat.

[oldsport]

>>I'm running lean with 37.5 pilots and 127.5 mains.....go with 40 pilots and 140 mains

Thanks.

I've heard that the MAC exhaust is fairly restrictive (is that true?) and that it's made that way so that you don't necessarily need to rejet. I've been thinking that the problem is more with the K&N's - but now you've got me wondering.

The only way I know of to test the main jet without putting it on a dyno is to run it to top speed in 5th and then back off the throttle slightly. If it picks up RPM, then it's lean. I don't see myself doing that .

[brokenrod]

On my old 81 gpz1100 with V&H 4into1 and pods, it had 140 mains and 40 pilots. That setting was just about right- if anything, it was just a tad on the rich side at idle but i think that was due to a weak spark from the coil.

[red and black]

i am in the process of installing 140/40's in the BS34's on my 81 GPz1100 with V&H semi-open pipe, will let you know how it rolls.
replaced header gaskets today (at the exhaust port) as they were pretty leaky.

[oldsport]

140/40s - B/R and R/B - Thanks for the replies.

Let me know of any updates.

[MFolks]

I got this from the KZ rider website:Re:Another 81 GPZ.
Saki Jockey wrote:

What are you running for Carbs / jets?


TK-22 carbs from an LTD(Same carbs on 550 A1-A3/C/D1, but D1's are black and have bigger main jets.)

Mains drilled to 99 (from 92 on the LTD, but D1's come with 94 mains).

Pilot jets drilled to 34 (from 32).

And I'm using Dynojet DN0205 needles from the 2305 kit. 3rd clip from top (out of 6possible positions), no shims
This is similar to the K&L rebuild kit Y77 needle which is identical to the Kawasaki 4D93 needle which is the adjustable version of the stock needles. On the Y77 or 4D93 you want the 2nd or 3rd clip from the top (out of 5 positions). (2nd mimicks the fixed position of the stock needle exactly.)

Mixture screws are about 1.25 to 1.5 turns out.

That was just a rough setting, but it seems to be flawless. Starts easily (even without a battery). Full power past redline, no pops, no hiccups, and no dead spots. I may have gotten lucky on the setting.

[Andy the gringo]

Mike the info you posted is for a bike half the size that runs an entirely different brand of carb.

[MFolks]

Sorry! Found it on Kz rider and thought it might be of use.

[oldsport]

Originally Posted by MFolks

Sorry! Found it on Kz rider and thought it might be of use.

Not to worry!

Thanks. I'm keeping the info for when I get my next 550.

This was my first - 1980 KZ550 bought new. What a great bike!

(Mike) Velasco pipe, K-81 Dunlops, S&W shocks, superbike bars, rattle can gold wheels - whew!

[elr658]

Mike Velasco is still wrenching Hondas in the PNW.

[oldsport]

Originally Posted by elr658

Mike Velasco is still wrenching Hondas in the PNW.

I had just figured that out. He's at a shop in Bremerton, WA
Washington, Honda, Yamaha, motorcycles, ATV, dealer, The Brothers Powersports

There's a picture of him in the employee photo section. I'd recognize the hair anywhere-although it's a completely different color!

I need to print my photo taken at Riverside and ride the ferry over there and have him autograph it.

Mike Velasco on the back with Steve Wise - factory superbike at Riverside:

See more photos that I took that day
Good ones of Lawson's Kawasaki

[Eken]

Hi, first i want to say sorry for my bad english..
My dad have a Kawasaki GPZ 1100 -81 and he
have put a -83 engine on it and convert it to
carburators. The carburators come from a Z750 -83,
and now to the question he was wondering what airfilter
he should buy or does he need airbox.
And if so from which bike would the airbox fit almost right on.

[oldsport]

Originally Posted by Eken

Hi, first i want to say sorry for my bad english..
My dad have a Kawasaki GPZ 1100 -81 and he
have put a -83 engine on it and convert it to
carburators. The carburators come from a Z750 -83,
and now to the question he was wondering what airfilter
he should buy or does he need airbox.
And if so from which bike would the airbox fit almost right on.

I believe the carburators on my bike also came from an 83 GPz 750. A previous owner changed them so I'm not positive.

The carbs are labeled: Mikuni BS34 K

I don't know which airbox might fit. Maybe someone else will be able to answer.

My bike has K&N Pod filters - RC-0984
http://www.knfilters.com/search/prod...x?Prod=RC-0984



I'm currently trying to get the jetting adjusted so that the bike will run smooth.

Your english is fine. You should hear some of my relatives try to speak it and they were born here!

[red and black]

i installed the 40/140 jets in my BS34's (81 GPz1100 with headers and pods). i also added one washer under each needle C-clip. the bike is still slow to warm up, and seems to have a little light "blow-back" under light throttle, but 95% of the time it runs really strong.

the #140 pilot jets i used had maybe 3-5 small holes on the sides, but the originals didn't have these holes. anyone know if this makes a difference?

[63Ronin]

I have an '84 GPz750 project that I'm working on. Bought a parts bike for a few odds and ends. I also have an '84 GPz1100 that I was thinking about converting to carbs. Glad to know that my spare set of BS34's will go on the 1100 with re-jetting.

Big question... Important question...best way to clean carbs? As in the little passages, which are a bit gummed up. Any one?

Thanks

[oldsport]

Originally Posted by 63Ronin

Big question... Important question...best way to clean carbs? As in the little passages, which are a bit gummed up. Any one?

Thanks

There might be something better but I used Gumout Carb + Choke Cleaner and Greased Lighting

Be careful around paint. The Gumout will take it off.



Recent pic of my GPz1100 at September Backfiremoto night in Seattle

[StarGate]

Depending on how badly the passages are you might need to soak the bodies and other metal parts in something a little stronger than the spray can cleaners. Berrymans makes a cleaner that comes in a 1 gal or so size can with a parts basket for holding small parts like the jets. Some auto parts stores carry it and others can order it for you. If you choose to use this type, be sure you strip the bodies all the way down and remove anything that is not metal because it will eat plastic, rubber, and paint. Cost for the last can I bought was around $32 but you can seal it up after use and use it many times. After I soak them, I rinse them thoroughly with water then blow them out good with compressed air checking to make sure I can feel the air exit the other end of the passage.

P.S. Someone posted a while back that they also make an eco friendly version of the same product that didn't give very good results.

[MFolks]

Try this method of carb cleaning I got this from KZrider.com - Home)

Lemon Juice Carb Cleaning

If it was me, I'd pull the top covers off, pull the slides out, drop off the bottom bowls, remove pilots/mains. Then with the rest of the carbs still assembled boil them in some lemon juice. You'll need a big roaster pan, a little over a gallon of lemon juice (cooking supply stores), and an understanding wife/girlfriend cause the sh*ts gonna stink a little.

Boil them for about 15 minutes, then rinse them really well and blow them dry with compressed air (make sure all passages are clean). You'll be amazed at how clean they come in that short of a time.

I just did a set yesterday after hearing about it from a buddy who's used lemon juice on a couple dozen racks of carbs. After a couple of minutes at slow boil the lemon juice starts to foam up a little (careful not to boil over) and you can see all the sh*t just dissolving.

After boiling them for 15 minutes (might have to roll them around once to make sure you get the entire carbs) rinse them really well and blow them dry with compressed air. The carb bodies will be kinda chalky looking at this point. I used a toothbrush and PB blaster to put a little luster back into them and then put my internals back in.

I had pulled the bowls off, removed the floats, float needles and seats, jets, and air/pilot screws as well as the top covers and slides just to make sure no crap got itself wedged inside those passages.
After putting the carbs back together and bolting them up not only do they look great but the bikes running MUCH better with all the jet passages finally cleaned out.