KDXRIDER.NET

So. My 36mm PWK turns up today. There is no way its gonna fit in the inlet and airbox boot. Has anyone else made this mod before? I know I'm going to have to change the inlet stub, and drill a hole in it for the 2-stroke pipe or just go pre-mix. BUT! Is the airbox different on this model also? Or do I just change the rubber?

Any UK users know where the hell to get parts from?

you may of opened a can of worms...if you change the inlet boot then it may not fit the reed cage (too big?) so you may have to change that too provided it fits the cylinder block etc...also you may need to ditch the oil pump & run it on mix..then coz you have mixed the fuel your going to have to re-jet etc etc depending on wether you use the SR carb or the larger carb..if you just want to ride your sr as a trail bike then it may do just fine over here as it is albeit a little under powerd compaired to the `enduro` kdx...you could always sell it & buy a 200 or 220 there`s always plenty on our ebay ..just a thought.

pretty sure we already mentioned the 36mm carb wouldn't work for you. As mentioned in your other thread, it shares the carb body with the 38/39mm carbs, which are much too large for your bike.

Best bet is to find a kdx200 carb.

the carb came from a kdx, if the carb was bored out to 39mm the inlet stub would not exist as the outer diameter is 39.5mm, so im pretty certain it has been bored out from a 35mm

inlet side - ID 36 OD 39.6
air side - ID 54 OD 59

according to this guy on ebay its just air boot and inlet stub

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 500wt_1156

though I have emailed him to confirm.

I can easily get a union to tap into the inlet stub to keep the auto lube its just knowing what I need to buy as its impossible to get a parts fiche so I can do some cross referencing!!!

Has anyone ever found the parts fiche for the SR? That would be an excellent late xmas present!

bit more information on the SR

http://www.users.on.net/~madmitch/KDX/

so far ive found 1 guy who managed to cram the carb into the stock boots with much lube.

I think the SR came with a dinky carb... not the standard 35mm carb that came on US models.

yeah it does have the puny carb, just needing to know what parts to order to fit, asked someone who's done it on ebay and he reckons you just need the airboot and to chop the airbox down... yeah :p we'll see

I see. I guess airbox and inlet sounds about right then. You'd loose the injection system though.

nah, i could easily tap any old union into the new inlet stub, although i may decide to lose it anyway, god knowhere where im going to get these crazy dual throttle cables from

moto_psycho wrote:nah, i could easily tap any old union into the new inlet stub, although i may decide to lose it anyway, god knowhere where im going to get these crazy dual throttle cables from

Mmmhmm. And how to you figure on reconfiguring that pump accurately for the higher quantity of fuel and air? I know the pump on my old 71 has an adjuster, but I don't have any idea how you'd go about figuring how much more it needs to pump. Seems safer to go with premix. Maybe someone more familiar with the SR will know.

juliend wrote:

moto_psycho wrote:nah, i could easily tap any old union into the new inlet stub, although i may decide to lose it anyway, god knowhere where im going to get these crazy dual throttle cables from

Mmmhmm. And how to you figure on reconfiguring that pump accurately for the higher quantity of fuel and air? I know the pump on my old 71 has an adjuster, but I don't have any idea how you'd go about figuring how much more it needs to pump. Seems safer to go with premix. Maybe someone more familiar with the SR will know.

+1

I have a 1989 KDX200F1 - the Australian version of the SR model.

I replaced the tiny 28mm carby with the KDX 35mm carby and it required a new air box boot and inlet rubber to fit the larger carby. I also fitted the air filter fron the "E" series which required a new filter cage etc. This was in the days before EBay, so if I was doing this mod today I would just buy a complete E series air box off EBay. Much easier and probably cheaper as I used new OEM parts at the time! I had to open up the reed block insert with a grinder to match it to the larger inlet rubber, and I also did away with the oil pump and just run pre-mix. You will need to fit the single throttle cable from the E series.

Fitting this carby make a BIG difference in performance! Well worth doing.
(I've now fitted an RB carby so the old KDX goes even better!)

Cheers.

Kind of very helpful for a first post Dodger! Welcome to the forum

As others have said, you will need to change the air box and boot. The dual throttle cables are available, but I think scrapping the oil pump would be the best option.

I have a spare SR 220 motor, it seems to be identical to the R version, however I think the stators are also different and maybe the gearbox? I've never found the mircofiche.

airbox ordered... no inlet stubs on the bay so gonna have to go brand new or file mine out maybe...

Dodger wrote:I have a 1989 KDX200F1 - the Australian version of the SR model.

I replaced the tiny 28mm carby with the KDX 35mm carby and it required a new air box boot and inlet rubber to fit the larger carby. I also fitted the air filter fron the "E" series which required a new filter cage etc. This was in the days before EBay, so if I was doing this mod today I would just buy a complete E series air box off EBay. Much easier and probably cheaper as I used new OEM parts at the time! I had to open up the reed block insert with a grinder to match it to the larger inlet rubber, and I also did away with the oil pump and just run pre-mix. You will need to fit the single throttle cable from the E series.

Fitting this carby make a BIG difference in performance! Well worth doing.
(I've now fitted an RB carby so the old KDX goes even better!)

Cheers.

what did you do to get rid of the oil pump, remove it and make a plate to put in place or just left it to run dry?

Yes, I just removed the pump and made a plate to blank off the hole.

You won't be able to "file out" the original inlet stub to fit so you'll need to get a new one. Part no. 16065-1181. The part I had to grind out is the plastic or nylon bit that inserts into the reed block to smooth out the flow into the reeds. The SR hole in the insert is too small for the larger inlet rubber. As far as I know, the insert isn't available as a part on its own.

Cheers

cool, cheers for the heads up mate! ill get the files ready!

i have done mod like what you are doing, i gain nothing but more fuel consumption, more smoke and spoo, less bottom end and nothing amazing at the top end. i removed everything and went back to just the stock wr200 mikuni TM30mm carb. what a waste of time, money and effort.

any taker for the complete kdx200 airbox system, and carb? i am selling mine