TM34 Carb on a KDX???

[Budget_89KDX]

Hey guys long time no see been busy and blew the kdx up but its about to be back on the trails soon

Anyways the reason im posting is i just fininshed my yamaha blaster build and its now a VITOS 240 BBK that i sent to KEN OCONNOR RACING to be done and its now sporting a 72.5mm BBK and is down right nasty!!!

But its currently rocking the stock but jetted VM26SS carb and while its running it aint at peak performance and ken recommended a bigger carb so i traded for a TM34 mikuni from a suzuki LT250R thats jetted at 330/45 with a 6FP63 needle unfortunately it wont fit due to its size and demensions those flat slide carbs are monsters in size so i cant use it on the blaster but the keihin pwk 35 does fit it like a glove so i swapped them and the mikunis right at home physically on the kdx so i plan to run the mikuni on the kdx and keihin on the blaster.

My question is now that you guys are up to date what will the mikuni need to be jetted at to work on the kdx?I have every jet for the mikuni from 230-340 currently theres a 330/45 with the 6FP63 jet needle and since im new to this carb im not sure if itll supply enough fuel with the current setup and if not what will i need to change?

The kdx isnt as built as the blaster its got an FMF desert fatty,boysens,and a uni filter so im more than sure the flatslide mikuni will feed it and i hear these carbs are nice anyone familiar with them or used/using one.

[KarlP]

I don't have any experience with running mikunis on KDX's. I'm sure others on here do.

It does seem to me though that if the KDX keihin is good for the 200cc Blaster it ought to be pretty good for the KDX. When it comes to carbs, bigger is not always better........

I'd hate to hear that you tried a different carb and blew up your newly repaired KDX.

On a slightly different topic, wouldn't that blaster motor be great in a KX/YZ/CR frame?

[Budget_89KDX]

I don't have any experience with running mikunis on KDX's. I'm sure others on here do.

It does seem to me though that if the KDX keihin is good for the 200cc Blaster it ought to be pretty good for the KDX. When it comes to carbs, bigger is not always better........

I'd hate to hear that you tried a different carb and blew up your newly repaired KDX.

On a slightly different topic, wouldn't that blaster motor be great in a KX/YZ/CR frame?

Well ive checked at blaster forums where im also a member and most guys are running the keihins on heavily modded big bore kits like this and prefer them over any others.

Im in the process of rebuilding the kdx but its xmas and my daughter got one hell of an xmas so funds are scarce for toys.This minkuni flat slide was off a LT250R so i dont see why it wouldnt be close in its current state of tune but yes me too id hate to see it blow up again.

As for the motor in a different frame im skeptical on how good it would be its an outdated port layout seeng as its from a 70's dirt bike design even modded like this one is its still inferior to say the port layout and design of a YZ.But ill tell you this its no slouch!I can whether i want to or not lift the tires up all the way into 4th gear when hammering on it!

[SS109]

From what I have heard (no personal experience) the Mikuni carbs are sensitive to jetting, especially compared to a Keihin PWK, and almost impossible to get spot on. Like I said, personally I don't know, just what I have read.

[KarlP]

As for the motor in a different frame im skeptical on how good it would be its an outdated port layout seeng as its from a 70's dirt bike design even modded like this one is its still inferior to say the port layout and design of a YZ.But ill tell you this its no slouch!I can whether i want to or not lift the tires up all the way into 4th gear when hammering on it!

I've just been thinking of a simple, air cooled, 2-stroke bike. The power is not as important as the chassis. I would try to tune it for more low end and sacrifice top end

[Frysk]

From what I have heard (no personal experience) the Mikuni carbs are sensitive to jetting, especially compared to a Keihin PWK, and almost impossible to get spot on. Like I said, personally I don't know, just what I have read.

You'r right about that,
On my old Honda MTX I had a Mikuni TM24 carb and it was realy hard to get the jetting right.. never got it realy spot on tho...

Now I've got a Keihin 24mm (round gasblock) on my Honda MBX (same engine) and I only had to change the main jet 3 times and play a bit with the airskrew to get the jetting spot on.

But I always had the idea that the Mikuni gave a bit sharper power delivery.. but that could just be me.

[David_L6]

I wouldn't bother with a Mikuni. I took the Mikuni carbs off of our two CR250s and replaced them with Keihin PWK Air Striker carbs. Much better now.

[Julien D]

I would think replacing the PWK with a TM would be a pretty major downgrade. Any particular reason you want to do this?

[Budget_89KDX]

I would think replacing the PWK with a TM would be a pretty major downgrade. Any particular reason you want to do this?

I have the two carbs and want to use both the orignial plan was to use the mikuni on the blaster but it requires a custom intake i dont have the loot to buy and dont want to but the pwk fits without the special intake.

If i could make the mikuni work on the the blaster i would but its not possible at the time so i figured id swap them.

How difficult are you guys talking?Were there any major issues.Got a rack of these flat slides on a buddies 87 GSXR1100 and theyre not too bad to tune but this aint an inline 4 cyl bike either.


As for a downgrade how much of a downgrade arent these both performance carbs?

[Julien D]

I've just always preferred the PWK over the Mikuni TM's. If you're set on trying it, I would just stick it on and run through the jetting procedure. Shouldn't be too difficult, and what have you got to lose? The biggest problem is you have no "stock" baseline to start from. As long as the stock settings in that TM aren't lean enough to do any damage, you have nothing to worry about.

[Budget_89KDX]

What do you think of the TM's current jetting?

It fed a LT250R would the kdx's fuel reuirements exceed the LT250's?

[fuzzy]

Sell the TM34 on ebay for $40-50, and find an OEM KDX 35mm for the same money....Prob solved.

The TM will work fine on the KDX if it physically fits, but it's not the carb the PWK is.....and you're on your own jetting it.

[KDXsg]

I agree, Keihin produce better carbs than mikuni. My personal experience is bigger is not always better. my kdx200 perform better with a 30mm carb than to a 35mm carb believe it or not. also depend on the kind of terrian you are in. i am always riding in woods, hills and tight single track so a smaller carb will be better in my case. the above stated is with my limited knowledge.

[fuzzy]

If you like a smaller carb, get a 33mm KDX PWK from a 220 guy.

[Julien D]

I agree. However, an RB modded 35mm PWK should have better low end response than the stock 220 33mm and better top end performance than the stock 35.

Just throwing that out there. ^.^