Alternative carbs

[showtime]

Thanks for the good information Ben and please keep us up to date on your progress. Do you have any details on the carbs such as what years they were on the bikes, part numbers to look for or any identifying characteristics to help in my / our search for similar ones ? Seems like 80% of the folks selling carbs have no clue what they have or where they came from....frustrating

[audijunky]

Re: How did you handle the throttle cable issue?

Originally posted by mro
I've got dual cables on the hot rod. Think there off an early Kaw...
Last summer I tried to shorten the retun cable
Could not get solder or silver solder to stick to cable end
Even made a mold to form a new end over the cable, mold worked great but when I tested by pulling on it the end came off. Then made a end out of steel with a tappered hole for the cable and welded the cable to it. Worked great for a few hours of riding before it can loose.

Finally went to a local shop, Cycle Salvage. Guys let me sort thru there used cables. Found one that was plug and play for $8.00.

You should be able to find the control/cables same way.


mro

DID you try using one of those small crimp on lead fishing weights .I think there called litre weights. Come in all sizes, work pretty good on fishing line, would probably work on a throttle cable??

[mro]

crimp on lead fishing weights

called "split-shot"
No way they would work.


mro

[audijunky]

you dont think so huh, well jus thought I'd through that out there
Have you tried it

[mro]

Have not tried one on a throtal cable, but have used them now and then over the last 50 years fishing. Split-shot Lead is a little on the soft side.


mro

[Shuriken]

Showtime, I understand your frustration.

I joined this board in 2002. I cannot tell you how many times I've gone through "carb hell" since then! I'm sure I've lost hair over it, not to mention the exposure to carb cleaner and gasoline! Within a matter of days, I obtained a result from the ZRX carbs that I had tried to achieve over a span of 6 years with the XS carbs. So naturally, I'm happy about this.

Recently, I spent about a month researching replacement carbs after seeing stuff come up on the board here and there. (Thanks goes to pggg for discovering the ZRX carbs, to gaffer77 for helping me evaluate XJ-900 carbs, to bfreehill for his help with FJ carbs, and to others for help with other carbs). Most of that research is summarized here... The research paid off.

After all the research, I sought the following carb options in the following order:
1. Keihin 36mm CVK4 carbs from a 2004 ZRX1200
2. Mikuni FJ1200 carbs from a 1985 FJ1200
3. XJ-900 carbs from a 1988 FJ-900
4. GSX-R750 "Slingshot" carbs

I wanted the best carbs with the least hassle. While people have modified carbs from various other 1100cc bikes, I was not interested in cutting up carb bank rails and grinding here or there to make the carbs fit. I did not want to have to use individual filters or to have to replace fuel petcocks, either. Part of the reason I didn't want to have to do any mods is because if the replacement carbs didn't work, I wanted to be able to fall back to the XS carbs.

So, using the research of others combined with my own, I discovered that the ZRX carbs were 36mm across all years and were the same carbs, except for jetting variations. I specifically avoided any of these carbs that I thought would be "California" model carbs. Also, I knew that the ZRX carbs were closely spaced in comparison to the XS carbs, so I knew they would fit the manifolds. pggg said they would fit the stock airbox if you slide the airbox forward, and I discovered this to be true as well. Although space around the petcocks is tight, the OEM petcocks can be used as well. So with all of this in mind, ZRX carbs became my #1 choice. I found several sets on eBay, but ended up purchasing this 2004 set out of Georgia.

At the same time that I purchased the ZRX carbs, I bought a set of FJ1200 carbs from eBay as well, to have on standby in case the ZRX carbs sucked. The FJ1200 carbs, from my understanding, are also pretty much bolt on and go. The FJ carbs and ZRX carbs require a cable modification, but that's about all. bfreehill of Colorado put FJ carbs on his XS and said he could lift the front end.

My third choice would have been 1988 XJ-900 carbs. These carbs are from a non-US Yamaha and are also pretty much bolt up and go. One XSive installed these and also said they really woke up the XS.

My fourth choice would have been the Slingshot carbs. I indeed found a set on eBay and was planning on bidding if I lost the bids on the ZRX/FJ carbs. By the time I won the bids on the ZRX/FJ carbs, the Slingshot carbs were gone. Nobody bid on them.

So now my bike is set. About a month ago before the carb upgrade, I started getting some top end noise that troubles me. Ironic. But now that I have good carbs, I may consider springing for a bore kit.

As far as researching the ZRX carbs, I used parts lists and schematics from http://www.zrxoa.org/webpages/genera...toryspecs.html, http://www.bikebandit.com, and http://www.powersportspro.com . I also used sources from here and talked to members of various Kawasaki groups.

If you look at the specs, it appears that the same carbs were used on the ZRXs from 1999-05. Only jetting is different. It looks like the 2004 model carbs were used for an engine of 1164cc's. I'm sure these carbs would work with the XS big bore kits.

Ben

[Mathh]

Originally posted by mro

called "split-shot"
No way they would work.
mro

I always used the screw-on cable ends for my throttle cable, which I then screwed and soldered on. Works great.

[audijunky]

You got or know of a pic somewhere of those screw on cable ends. I never heard of them??

[TopCatGr58]

Hey Steve,

I just tried looking thru some ONLINE auto parts stores, but they are a PITA, they want you to look for parts by year/model of car!

They are in the HELP section, you know, all of those odd parts that you need to find like door lock knobs, window crank handles, etc.! It's a small brass barrel that has a screw in it's end, you fit the cable thru it, and then screw the screw to lock the cable in place! I've used it to fix a couple of cable actuated examination tables we use at our office. They use bike brake cables to release a lock mechanism to allow you to raise/lower and then relock the table in position. The cables soldered ends came off, and the company didn't provide replacement parts for them anymore, so I fitted the clamp on the end with a new bike cable, worked just fine!

Folks use them to secure cable ends like hood locks, emergency brake cables, etc.!
T.C.

[audijunky]

Thanks TC. That good to know. I am currently fitting some carbs off a 93 gsxr 1100 and may need some. Currently at the stage of working out throttle cable(s) holder. I just bought a throttle tube and assembly fordual cable 1" bars off ebay for 7:75 shipped. Picture looked good but I got a feeling for that price the quality may suffer. Shipping was more than the part. Paid 1.75 for part and 6.00 for the shipping. Got some pics here if anyone is interested. my carbs
cheers

[Shuriken]

I've determined that I'm going to have to sort out one small problem with my current ZRX carbs setup. After about 20 minutes of riding, the bike develops a stumble below maybe 2000 rpm. This isn't good because the bike really stumbles when you gently roll on it from a stand still. Revving the engine in neutral once will get rid of the stumble (probably leaning up the mixture to overcome richness?).

I checked the plugs and they are sooty at idle, which surprised me. I checked the idle screws and they are 0 turns out from lightly seated.

Bike runs fantastic except from that stumble. Also runs great for the first 20 minutes or so. Sounds to me like it is either float level and/or pilot jets, or both. I don't want to mess with float height, so I suppose it's time to play around with pilot jets.

Anyone have any suggestions?

[mro]

0 turns out from lightly seated

and possible running rich now?

Is the throttle cable adjusted right? Any slack when all the way returned? If not the cable then most likely float height.


mro
btw, do these carbs have different jets/adjustment for throttle range or are they CV carbs? Then could be pilot jet.

[Da-Bubble]

Disappointing

I installed a set of 2000 ZRX 1100 carbs on the Mad Mos and they would not even idle! When reving, they pop and backfire. I cleaned them before install and they all looked imaculate. Sync screws still have factory paint on them indicating they've never even been messed with. I took them back off and put my old ones back on. What a big disapointment since they were supposed to be bolt-on and go!

I have not given up on them but I really don't know where to start.

[Shuriken]

Da-bubble - not to worry. I'll sort it out and help you with yours if you decide to stick with them. Does it pop and backfire only on decelleration or when you rev the engine? I just reconnected my vacuum ignition advancer and that eliminated the popping and backfiring I had on decelleration.

Part of the reason I went to ZRX carbs was because mine are only 4 years old, so I can easily get or try out different carb jets or parts.

Each person's XS is in a different state of tune, some are stock, and some are not. People say with my 4-1, I'm not going to have great exhaust scavenging and low end performance anyway. It's obvious to me though that these ZRX carbs are better for my situation. If I can sort out the bottom end, I'm good to go.

However, I need to do a bit more research on the ZRX carbs. For example, float height comparisons, pilot circuit comparisons, etc. I'll start a thread soon where people can post their jet numbers from their ZRX carbs and we'll start to sort it out.

I think those who have properly tuned and mechanically good XS carbs wouldn't gain any advantage from using ZRX carbs except for parts availability.

If anyone wants to try the FJR carbs, I have a set. Also am thinking of ditching my XS carbs...

Back to my idle mix problems.... I'm going to check plug color at full throttle, since float height affects all circuits. If it looks good, I'll probably leave the float height alone and will concentrate on just swapping pilots. I will start with the easy adjustments first and then move to other things. However, I've already experimented with jet needle position on these carbs, and as far as I can tell, they are fine in the middle position. Those of you closer to sea level may need to drop the needle.

[Dragon Tamer]

Ahh, I may be wrong here (has been know to happen at least once before) but I have been thinking back a year or two when I helped a friend tune up a bike and I keep thinking that the idle mixture adjustment on the ZRX carbs were air adjustment and turning them in richened up the mixture instead of leaning them out.
Remember, I am relying on a two year old or so memory and I may be accidently thinking of another bike so if I am wrong just go ahead and tell me. I will have forgotten about that right away too!