'17 250SX stiff throttle pull

LumpDog841
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LumpDog841
Edited Date/Time 11/4/2022 8:39am
Ok, I tried everything I can think of (cables, throttle housing, springs, handlebar bearings) and was wondering if anyone else has a really stiff throttle pull/twist on their 250SX (Mikuni carb). From the photos below, I believe there is something wrong with the housing the slide interface that is causing a lot of drag. Thoughts?












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ktm-5
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ktm-5 10/2/2017 11:35pm
10/2/2017 11:35pm
Well it looks like you need a new slide. If it were me I'd buy a new slide and take a piece of fine sandpaper or even a scratch pad and try to clean up the carb where the slide goes making sure there are no burrs in there. Being you have gone through everything else that has to be where the problem is
digger
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digger 10/3/2017 1:05am
10/3/2017 1:05am
I didn't like how stiff the pull was on my 17 xc300 either, so I replaced the entire OEM throttle assembly and cable with one from a 14' xc300. The throttle pull is now as light as any 2t that I have owned.
http://www.motosport.com/oem-parts/part-number/51502010200?mmysource=kt… This kit also includes the rubber boot to cover the throttle housing even though it doesn't state that. Mine did anyway. You will also need the correct throttle cable for the 14' assembly as well.

The throttle slide that you have pictured is perfectly fine to be used. That nick won't have a noticeable effect on performance at all.
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ehr400
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ehr400 10/3/2017 5:19am
10/3/2017 5:19am
Holy crap James that is alot of gauling on the carb body, looks like something scraped it up. I would use some really fine scotch brite pad and WD40 on the carb body. Hard telling if your chroming has chipped on the slide but if it has on that corner take some scotch brite to that too, to get rid of the sharp snag, and hopefully prevent more from chipping off. See you Wednesday!

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LumpDog841
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LumpDog841 10/3/2017 10:49am
10/3/2017 10:49am
ehr400 wrote:
Holy crap James that is alot of gauling on the carb body, looks like something scraped it up. I would use some really fine scotch brite...
Holy crap James that is alot of gauling on the carb body, looks like something scraped it up. I would use some really fine scotch brite pad and WD40 on the carb body. Hard telling if your chroming has chipped on the slide but if it has on that corner take some scotch brite to that too, to get rid of the sharp snag, and hopefully prevent more from chipping off. See you Wednesday!
Yeah, it's pretty bad. Just bought a new carb, which should be here Fri. As long as I don't get sucked into work I'll be at coops wed!!!
LumpDog841
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LumpDog841 10/3/2017 10:54am
10/3/2017 10:54am
digger wrote:
I didn't like how stiff the pull was on my 17 xc300 either, so I replaced the entire OEM throttle assembly and cable with one from...
I didn't like how stiff the pull was on my 17 xc300 either, so I replaced the entire OEM throttle assembly and cable with one from a 14' xc300. The throttle pull is now as light as any 2t that I have owned.
http://www.motosport.com/oem-parts/part-number/51502010200?mmysource=kt… This kit also includes the rubber boot to cover the throttle housing even though it doesn't state that. Mine did anyway. You will also need the correct throttle cable for the 14' assembly as well.

The throttle slide that you have pictured is perfectly fine to be used. That nick won't have a noticeable effect on performance at all.
Yeah I installed an entire G2 setup hoping it would solve it. Unfortunately it didn't really make a difference. Setup I used:

https://www.g2ergo.com/store/ktmhusky-2-stroke-throttle-upgrade-kit/
seth505
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seth505 10/4/2018 10:14am
10/4/2018 10:14am
Dannyderasmo106 wrote:
What did you end up doing to fix this? Ive got the same issue with my 250sx
Did you mess with the slide/switch needles at all? Make sure the throttle cable and white plastic piece are seated in there properly. If not, it will feel hard/notchy when you twist the throttle.
Jeff_Crutcher 10/4/2018 11:06am
10/4/2018 11:06am
I was having a lot of problems with mine also- then I junked the cheap plastic throttle tube for the Pro Taper twister throttle tube. But it looks like you're having more problems with your carb.
DynoDan22
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DynoDan22 10/4/2018 12:12pm
10/4/2018 12:12pm
I put a '16 throttle assembly/cable and Keihin on my bike. The stock pull on my '18 150sx was very stiff with the mikuni. I thinks its a combination of the throttle housing not having the idler wheel and the mikuni spring being so stiff.
BR8ES
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BR8ES 10/4/2018 3:37pm
10/4/2018 3:37pm
I thought the 17+ pull was easy as can be... my Domino assembly is no different.
LumpDog841
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LumpDog841 10/4/2018 6:52pm
10/4/2018 6:52pm
Dannyderasmo106 wrote:
What did you end up doing to fix this? Ive got the same issue with my 250sx
At the moment my setup is a G2 throttle setup/Keihin Carb/'16 Motion Pro cable (not the cable G2 provided), and careful attention to how the cable is routed it seems really sensitive to the routing. I did buy a new Mikuni carb off ebay and got it to work well with the stock throttle housing. Truthfully it's a really frustrating problem that in my opinion shouldn't exist.
LumpDog841
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LumpDog841 10/4/2018 6:53pm
10/4/2018 6:53pm
DynoDan22 wrote:
I put a '16 throttle assembly/cable and Keihin on my bike. The stock pull on my '18 150sx was very stiff with the mikuni. I thinks...
I put a '16 throttle assembly/cable and Keihin on my bike. The stock pull on my '18 150sx was very stiff with the mikuni. I thinks its a combination of the throttle housing not having the idler wheel and the mikuni spring being so stiff.
That is what I thought until I pulled the spring out of my YZ125 (same spring), and had the same stiff throttle pull.
LumpDog841
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LumpDog841 10/4/2018 6:54pm
10/4/2018 6:54pm
Jeff_Crutcher wrote:
I was having a lot of problems with mine also- then I junked the cheap plastic throttle tube for the Pro Taper twister throttle tube. But...
I was having a lot of problems with mine also- then I junked the cheap plastic throttle tube for the Pro Taper twister throttle tube. But it looks like you're having more problems with your carb.
Yeah I tried G2 "jimmy" bearing system with no improvement.
LumpDog841
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LumpDog841 10/4/2018 6:57pm
10/4/2018 6:57pm
BR8ES wrote:
I thought the 17+ pull was easy as can be... my Domino assembly is no different.
I got mine to a good pull after I bought another mikuni off ebay, and used the standard throttle housing. Though it wasn't a simple bolt up. I had to spend a lot of time getting the cable routing perfect as it seems really sensitive to how the cable is routed under the tank and the angle of the interface to the top of the carb.
LumpDog841
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LumpDog841 10/4/2018 7:02pm
10/4/2018 7:02pm
Thanks for the reminder gents because of this thread popping up again this reminded me that the dealer still has my f-up carb awaiting a KTM rep to look at it. Though they've had it for a year soooooooo, not holding my breath.
BR8ES
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BR8ES 10/4/2018 7:56pm
10/4/2018 7:56pm
BR8ES wrote:
I thought the 17+ pull was easy as can be... my Domino assembly is no different.
LumpDog841 wrote:
I got mine to a good pull after I bought another mikuni off ebay, and used the standard throttle housing. Though it wasn't a simple bolt...
I got mine to a good pull after I bought another mikuni off ebay, and used the standard throttle housing. Though it wasn't a simple bolt up. I had to spend a lot of time getting the cable routing perfect as it seems really sensitive to how the cable is routed under the tank and the angle of the interface to the top of the carb.
Interesting, shame you had to go thru all that. Seems to be hit and miss regarding this... glad you got it sorted.
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LumpDog841
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LumpDog841 10/5/2018 3:59am
10/5/2018 3:59am
BR8ES wrote:
Interesting, shame you had to go thru all that. Seems to be hit and miss regarding this... glad you got it sorted.
Yeah it's been frustrating to say the least. Think I've spent close to a grand on carb relate stuff, when it should have been sorted out at the factory. Love the bike, but this has been a thorn in the side.
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erik_94COBRA
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erik_94COBRA 10/5/2018 6:09am
10/5/2018 6:09am
Mine became very stiff after changing to new ODI grips. Can see where the outside of throttle tube is rubbing on housing. Lube helps for less than 1 moto. Even when new, pull required more torque than other bikes with domino style throttle.

Will report back after more investigation.
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Keating
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Keating 10/5/2018 10:50am
10/5/2018 10:50am
Mine gets hareder to pull also after a couple of motos.... It gets much better after I lube the cable and I'm pretty sure my problem is in the elbow of the cable inside the throttle housing!! I have ordered a Motion Pro cable to see if it cures my 250's ailments!!

It seems these SXs & TCs have a couple problems that are sporadic and only affect a few..... Like the jetting.... My bike runs great with stock jetting/needle dropped 1 click, others are having all kinds of problems!!! Annoying! I love my 250SX but these issues are a PITA!!

Will also keep you guys posted!!
Dannyderasmo106 10/5/2018 12:17pm
10/5/2018 12:17pm
Keating wrote:
Mine gets hareder to pull also after a couple of motos.... It gets much better after I lube the cable and I'm pretty sure my problem...
Mine gets hareder to pull also after a couple of motos.... It gets much better after I lube the cable and I'm pretty sure my problem is in the elbow of the cable inside the throttle housing!! I have ordered a Motion Pro cable to see if it cures my 250's ailments!!

It seems these SXs & TCs have a couple problems that are sporadic and only affect a few..... Like the jetting.... My bike runs great with stock jetting/needle dropped 1 click, others are having all kinds of problems!!! Annoying! I love my 250SX but these issues are a PITA!!

Will also keep you guys posted!!
I bought a motion pro cable, it pops off the slide every time i rev the bike, had to go back to stock.
BR8ES
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BR8ES 10/5/2018 12:39pm
10/5/2018 12:39pm
I have the OEM housing/carb on 17 250 and the Domino/smart carb on the 125, the 250 is stiffer by a bit. The traditional wheel in the Domino housing must be the difference, could be the spring naturally...But IMO it has to be the wheel and the way it is routed in the housing.
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AJ565
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AJ565 10/5/2018 12:56pm
10/5/2018 12:56pm
I have my 250sx here at work with me and I'm twisting the throttle and yes it's on the stiff side. When disassembled the cable is smooth and easy, the throttle is smooth and easy and the slide is smooth and easy. The carb sping is on the stiff side is all I've seen.

Now my question is, do you even notice that the throttle is stiff when you're riding? I never have noticed it being to stiff. I did ride a guys '15 250sx and his throttle was crazy easy to the point I didn't really like riding it as it felt like it was missing a slide spring.
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Keating 10/5/2018 8:05pm
10/5/2018 8:05pm
Keating wrote:
Mine gets hareder to pull also after a couple of motos.... It gets much better after I lube the cable and I'm pretty sure my problem...
Mine gets hareder to pull also after a couple of motos.... It gets much better after I lube the cable and I'm pretty sure my problem is in the elbow of the cable inside the throttle housing!! I have ordered a Motion Pro cable to see if it cures my 250's ailments!!

It seems these SXs & TCs have a couple problems that are sporadic and only affect a few..... Like the jetting.... My bike runs great with stock jetting/needle dropped 1 click, others are having all kinds of problems!!! Annoying! I love my 250SX but these issues are a PITA!!

Will also keep you guys posted!!
Dannyderasmo106 wrote:
I bought a motion pro cable, it pops off the slide every time i rev the bike, had to go back to stock.
That doesn't sound good!! We'll see!!
Keating
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Keating 10/5/2018 8:11pm
10/5/2018 8:11pm
AJ565 wrote:
I have my 250sx here at work with me and I'm twisting the throttle and yes it's on the stiff side. When disassembled the cable is...
I have my 250sx here at work with me and I'm twisting the throttle and yes it's on the stiff side. When disassembled the cable is smooth and easy, the throttle is smooth and easy and the slide is smooth and easy. The carb sping is on the stiff side is all I've seen.

Now my question is, do you even notice that the throttle is stiff when you're riding? I never have noticed it being to stiff. I did ride a guys '15 250sx and his throttle was crazy easy to the point I didn't really like riding it as it felt like it was missing a slide spring.
I definitely feel when it gets harder to pull out on the track. I can tell I'm having to work harder and my forearm starts feeling it in longer Motos!! You definitely can tell the difference on the stand too! Like I said, "mine gets much better after cleaning and lubing the cable and I have major drag on the cable elbow... Like earlier stated.... An annoying PITA
Dannyderasmo106 10/6/2018 10:32am
10/6/2018 10:32am Edited Date/Time 10/6/2018 10:34am
Ok so i just pulled the domino housing and cable off my 2016 125 sx and put it on the 250 and it worked perfectly, the pull is super easy and smoothe.
DynoDan22
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DynoDan22 10/6/2018 1:51pm
10/6/2018 1:51pm
Yup there is a lot of friction in the newer '17 and on throttle housing.
pete24
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pete24 10/6/2018 4:16pm
10/6/2018 4:16pm
i just bought a 19 tc250 and the throttle pull is unacceptable i ordered a 07 honda cr 125 complete assembly because it used a mikuni ill report back when it goes on
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BR8ES
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BR8ES 10/6/2018 5:46pm
10/6/2018 5:46pm
It will be just like the Domino assembly on the 16s and below... nice and easy.
seth505
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seth505 10/6/2018 6:29pm
10/6/2018 6:29pm
If I had to I'd say my 250sx is a little on the stiff side but my exc-f is so easy that it's almost scary. It's like zero resistance to twist the throttle, I'd like a little more haha.

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