i have a kaz 250 falcon, cranks great, but when u give it any throttle it goes dead, it sounds great at idle just dies out when u try to get moving, i have tryed to adjust the carb, but it seems to make no difference nomoter if i make it rich or lean it out, i have adjusted the valves. now im left scratching my head.

 

Try cleaning the carb. Sounds like you may have a clogged main jet. I know I had to let my falcon warm up for about 20 minutes (or till the green temp light came on) before I could even touch the throttle when I had the stock carb on it. I put a Mikuni carb on and it runs 200% better.

 

is hte mikuni an easy fit or do u have to do a lot of fab, and was it expensive

 

It was a fairly easy fit. I had to put a twist throttle and new cable on it. The Kazuma cable doesn't adapt to the new carb. I put a 34mm flatside mikuni on it and it was about $195 for the carb, throttle kit and foam uni filter. If I had to do it over I would have gone with the 32mm and saved myself some jetting on the carb because it was running too rich. You can get the flatside for $150 or a roundslide for $95 from DennisKirk.com. I went with the flatside because it is supposed to be more responsive. It is also the same carb that came on the older 250 quadsports so you can go right to a suzuki dealer and get jets and parts for it. It fit right into the intake, though it was a little tighter than the original. If you want to use the stock airbox you'll have to pull the screen assembly out of the tube and make a rubber sleeve to go from the carb to the tube. I originally did this and just installed a Uni filter directly on the front of the carb. I removed all the original piping to the airbox and took the top of the airbox off so I could store a spare plug, some rags and misc tools in. Everyone that rode my 250, including myself and my wife, noticed a considerable power increase with the new carb and filter. I'd guess it has close to twice the power than with the original carb, the hesitation when starting from a dead stop is gone, I've gained about 10 to 15 mph and I don't have to wait 20 minutes for it to warm up before I can touch the gas. You could always go to a Suzuki dealer or online (ronniesmailorder.com) and order the thumb throttle and cable for an older Suzuki quadracer (the 1988 Suzuki LT250RJ quadracer works) If you go to Raceway ATV's threads and look at some of the Falcon performance posts about sprockets and just performance on the 110 and 150 you'll see posts on how I modified my muffler and got more performance out of the engine too. If you can't find it just reply and I'll type up what I did and post it here for you.

 

hadaveha,

Sorry to reply before you may have had a chance to read my last post but I've been doing some more research into carbs and stuff for a performance manual for the Falcon 250. The 1988 Suzuki 250 quad has the mikuni flatside carb on it. What size it is/was, I'm not sure. The 2004 to 2006 have a 29mm mikuni. I would say that the 32mm mikuni would be the best choice as a replacement carb. The stock carb goes for $282.61 on RonniesMailOrder.com under the microfiche selection for OEM parts. The stock main jet is a 210, I currently have a 230 in my 34mm carb. I'm guessing that the stock 1988 carb was probably a 30mm. Maybe even a 32mm. I know they have made some power advancements in the carbs and engines since 1988 and probably downsized the carb bore size due to emissions (California, Smog and Californias colored ORV emission sticker program). The stock pilot jet is/was a #45 and that is what I just put into my new carb. The needle jet is Suzuki part number 13383-14510 and goes for $10.02 on Ronnies mail order.com and jet needle is Suzuki part number 09494-00526 and goes for $14.93 on Ronnies as well. I also replaced the pilot jet with a #45 which was the stock number for the 88 Suzuki. I just installed these parts tonight and started the ATV in the shop so I'm not sure what the trail performance is yet. The bike/shop was about 75degrees F and still started with no choke and no issues. Holding the front brakes on and jamming on the throttle still gave great response immediately after starting the engine. The tires were spinning on rough painted concrete and left some rubber and paint chips in a pile. This is with the Carlisle Turf tamer tires and not the stock Kazuma tires. The Carlisle's have about 10 inches of full width contact on the ground per tire, not the 1.5 inch or less that the stock tires have. From www.Denniskirk.com the 32mm round slide carb is 93.99 and comes with the following internal components;

SPECIFICATIONS:
Spigot OD: 40 mm
Bell OD: 58 mm
Main Jet: 200
Pilot Jet: 35
Air Jet: 2.0
Needle Jet: 159 Q-6
Jet Needle: 6DP17
Throttle Slide: 3.0
Inlet Needle Valve: 3.3
Choke Type: Lever

This may be just a bolt on and go carb. The main jet and pilot jet may need to be changed to the stock quad sizes though. Without trying it I can't say for sure.

The 32mm round slide carb has the following components installed;

SPECIFICATIONS:
Spigot OD: 40mm
Main Jet: 250
Pilot Jet: 45
Air Jet: 2.5
Inlet Valve: 3.3
Needle Jet: 389 Q-2
Jet Needle: 5FP17
Throttle Slide: 4.0
Choke Type:Button

This carb may also be a bolt on but I think the main jet may have to be reduced to 230 or lower. The stock Suzuki came with a 210 but that may be with a 28 to 30mm carb. The 230 jet may be just fine. Again I haven't tried this carb on my bike so I can't say how much tuning it will need. Plus it goes for 151.99 from www.denniskirk.com.

The 34mm carbs in round and square are the same prices as their 32mm versions.

From what I found with the stock carb the engine was running a bit lean. Especially when cold. If the money for a new carb is a problem you could always drill the main jet out a bit bigger or get a selection of main jets that are a bit larger from a local ATV dealer. Just ask for a Mikuni main jet(s) larger than the one out of your stock carb. The size number of the jet is/should be stamped on the jet itself. I believe my stock one was a 190. A 200 or 210 would probably add a bit of umph to your motor along with the addition of a better air filter and spark plug(if you haven't already changed out the crappy stock one). I am currently using a NGK D8EA. If you go to buy one, just buy 2. You'll never know when you may need one out on the trails. Get a M&M minis tube of candy, eat or throw out the candy and put a cotton ball lightly oiled with WD40 at each end with the plug sandwiched between them and snap the cap closed and put it under your seat with your tools. It will stay clean and rust free and you'll be prepared for an emergency on the trails. Don't forget to put some neversieze on the plug in the engine and the plug in the minis tube.

I have a setup guide written that some Redcat/Kazuma ATV dealers/salespeople/techs are using that I can email to you if you want to try some more basic setup tips to improve your performance before you upgrade the carb. Not that you won't be amazed at the improvement/performance in the engine with the new carb. If you want me to send the guide just send me a private message or reply on this thread with your email address and I'll send you the guide via email. It's in MS Word format with pics.

i8amm

 

my adult falcon wouldnt spin the tires if u put oil on the floor first

 

i8amm,

Thanks for sending the setup document. Great write-up!

Jim

 

Great advice on the workaround carb issue. Are you still happy with it and no issues? I like what you did with the airbox. Having the K&N up front...does that hurt you when you hit the mud and water? SEADAWG

 

I'm still running the 210 jet with no issues except running out of revs. I think the bike can do more but the cdi box is restricting my top rpm's. I haven't had any issues with water or mud. The filter is oiled pretty good and the water pretty much goes right over. It's mostly sand here so mud isn't a major problem. The filter would probably go into the airbox and mount up using a piece of round tubing or pipe between the hole in the inside front and the filter if you have issues.

 

You are the man. I have it at the dealers...he is working it free. He wants to try several different methods so he can fix the others. I showed him some of your ideas. If you were to buy a carb from Dennis Kirk, what model would it be and do the have the throttle cables and throttle? I would prefer the thumb, but can get over it. Also, he wanted to shave my weights on the CVT...I was telling him that I didn't think that was a good idea. They may pinch or get out of place??
The Jetting didn't do much, air filter did. He thinks I should just mount it up front like you. He said the manifold on mine break all the time? I was telling him that your new carb did wonders...with all your other stuff. You said 34mm carb bad for stock? What on Dennis Kirk can I buy right now that would be a perfect fit w/o having to buy aftermarket jets.

It has a K&N Air Filter
Jet next size up
After market pipe (back only)

I know you have told me a million times...I need it on SEADAWG level if you don't mind. At this point I'm tired and just want to point, click, buy and install. He is doing the labor and want to make the postings himself. SEADAWG ...too much time at SEA[img]i/expressions/face-icon-small-smile.gif[/img] He is saying this carb or that...but if we're wrong, the parts are on me. You know, you have done and can save money and aggrevation. SEADAWG