KDX 250 throttle compatability

radonc73 · Post by **radonc73** » 08:57 pm Dec 21 2006

Ok I took some measurements:

Carb boot: 4.5 cm cap to end of boot
Carb cap to bottom of tank at base of petcock
Cable Bend is 6.5 cm from cap to top of curve
Cable to corner where tank starts to slope up 2 cm
Cable is 2 cm underneath the tank.
Here is a picture of the routing my wifes camera needs charging so I can take a better one soon.

canyncarvr · Post by **canyncarvr** » 10:32 pm Dec 21 2006

Nah!! Not the worse...the more informative!!!

Likely it does leak air some, but any airleak that causes stickage is more likely to be seizure..not simply mechanical throttle binding. That missing gasket will be ASKING for some kind of grit to stick your slide, though.

DO replace it.

I suppose, in the realm of complete conjecture, that the missing gasket could cause the slide to come up too far..the needle getting out of the needle jet..and THAT keeping it from dropping back down. Doubt it. You could look down the throat of your carb, wick it open to ensure the needle doesn't completely clear the needle jet (what it regulates pretty much).

I adhere to the 'Fix what you know is broke!' postulate. Heck, it may even be a theorem!! Many times I've come across something not right in the process of trying to sort out 'some other' (I thought) problem. Lo and behold..fixing the 'somethng' took care of the 'some other' problem.

'Wing' meaning, based on other 250 pics I found on the web, the distended part of the tank that adds to the overall volume of an 'oversized' tank.

Look at YZs and some katooms for example. The 'subtanks' practically cover up the cylinder! ..I don't know how fuel gets from one side to the other on those things. YZs don't have a crossover tube.....

Looks like you would have enough room to run a curved tube (and its associated parts).

I'd be fixing the missing gasket first.

Looks like you got the 'unassisted pic posting' part down!

See? Things ARE progressing..and there's learnin' in the process!!

A complete aside..but...

My honey's Banshee throttle had a sticking problem. Two or three cables, some correspondence with MotionPro that ended up in their fixing their faulty throttle side termination, re-routing, carb body replacement! (Thank you Mr. Black!) cleaning and multiple carb resyncs later (Banshees are twin cylindered), the last trip to the sand showed the problem to be gone. What was it? Not sure. There was some grease in the cable splitter I cleaned out and I took off the electrical tape I'd thoughtfully wrapped around the splitter in an attempt to keep moisture out. It wasn't wrapped tight, but maybe it caused some interference inside the spliiter (one-to-two cable device).

The point of the fable is...it took a few months to get it..but it's got now, I'm fairly confident. A WOT stuck Banshee just might soil your drawers!!

You'll get it. Keep after it, and: You will learn a lot about your bike, AND it will be FIXED!!

quailchaser · Post by **quailchaser** » 03:05 am Dec 22 2006

Can you clarify "it sticks on me every once in a while"?

Like everytime I twist the throttle, but not when it's just sitting there with no one touching it.

Seriously though, does it go a whole ride with no sticking...then the next ride it sticks?

When it sticks, does it stay stuck for a period of time no matter what you do, or does it unstick with some sort of procedure?

Where in the throttle pull (ie. 1/4, 1/2, 3/4, WFO)? Is it always in the same place in the throttle pull when it sticks.

If you take the cable and unattach it from the throttle tube end, straiten it out, does that resolve your issue? Have you tried a different cable?

CC brought up a good point about routing the cable up and along the tank and forward. I can't tell if that is a good way to route the cable from your picture. Maybe a wider angle and a tad farther back shot could give us a better perspective on the routing. 1 picture with the tank on and one for comparison with the tank off.

I've yet to have a sticky throttlet that had any internal (carb) issues causing sticktion...doesn't mean thats not a posibility. Current discussion leads me to cable, cable install, cable routin or throttle tube/grips as one or more of the stickies gremlins. Also, what kind of bark busters (if any) are you using. I see guys all the time who have thier throttle tube to close to the end of the bars and then have that little mishap. Doesn't take much pressure from the handguards pressing on the grip or tube itself to cause it to hang up.

Answers to my above questions, will hopefully allow us to steer you in a better and more productive search and destroy mission.

You'll get it...most likely (like most of mine) it will end up being something stupid that should have been caught a long time ago.

I adhere to the 'Fix what you know is broke!' postulate. Heck, it may even be a theorem!! Many times I've come across something not right in the process of trying to sort out 'some other' (I thought) problem. Lo and behold..fixing the 'somethng' took care of the 'some other' problem.

Have to agree with CC...cept I ussually end up breaking something else in the process of fixin what was the known broke.

radonc73 · Post by **radonc73** » 10:33 am Dec 22 2006

It sticks about every 4-5 rides. When it does stick it is always when I go from about 1/4 to full throttle when coming to a hillclimb or when in sand and trying to keep up. I rarely open the throttle all the way so it may happen more often if I did but past experience has taught me not to. I usually use the 250 torque and go a gear higher b/c I don't want to have the rpms shoot up on me. The last time it happened I was going up a sand hill and when it stuck I hit the kill switch and let it wind down, I kept moving the throttle back and forth, when it sounded like it was going to die I let off the kill switch and it shot back up, I did this 2 or 3 times. I didn't notice much resistance on the throttle but that could have been the adrenaline running at the time. When it settled down I rode to the truck very carefully and loaded up. I feel my bunghole tighten everytime the power kicks in b/c I don't know if it will shut off. I don't have barkbusters, just the Acerbis handgaurds that don't mount near the throttle. I replaced the cable last year with an OEM one. I will try to take the pic in a better angle, when I get home from work.

KDXer · Post by **KDXer** » 10:55 am Dec 22 2006

Sounds to me like the slide is getting caught up if I'm understanding the

I didn't notice much resistance on the throttle

part correctly.

Is your needle bent ??

radonc73 · Post by **radonc73** » 11:10 am Dec 22 2006

I haven't noticed the needle being bent but I will pick a new one up and compare the 2. On the needle diagrams I see show a little nipple at the end of the needle but mine doesn't have that nipple. It is too small to show in a picture. These guys are right I am learning alot about my bike, the hard way but I guess that is the best way to learn, under pressure.

m0rie · Post by **m0rie** » 11:22 am Dec 22 2006

What needle code is stamped on the needle?

canyncarvr · Post by **canyncarvr** » 11:34 am Dec 22 2006

M0rie wants to see a too short needle?

You bring up the nipple part of the needle again. You read the answer to that, right? Don't worry about it.

I want to know when you're going to replace that gasket.

Gasket!

Gasket!

Gasket!

Gasket!!

Gasket!

m0rie · Post by **m0rie** » 11:55 am Dec 22 2006

How many grooves does the needle have at the top? If its short I wonder if you might have a Keihan 4T carb needle which is shorter than a 2T needle.

canyncarvr · Post by **canyncarvr** » 12:36 pm Dec 22 2006

M0rie: This is a true statement?

At WOT, the needle does NOT come all the way out of the jet block.

I'm sure that is true..but not sure enough that I want to say, 'This is so!'

...although I already did earlier on this thread. I asked radon to check that, but if there was a reply, I missed it.

m0rie · Post by **m0rie** » 12:55 pm Dec 22 2006

Yeah, let me dig up the diagrams. The 4t needles also have 6 clips vs the 5 clips on a 2t needle.

*edit* I think I might have read the diagrams backwards.

radonc73 · Post by **radonc73** » 12:58 pm Dec 22 2006

I am at work, I will get the gasket at lunch. I live 25 miles from the dealer and work about 5 so I didn't run out last night. I would think it is an item they would keep on hand if not I will order one. Going from memory the needle has 5 clip spaces, I am in the top slot, making the needle as long as it can go, I have not changed its position since I bought it. The needle is an R1368g I believe. I have it written down at home.

radonc73 · Post by **radonc73** » 02:18 pm Dec 22 2006

I am new to wrenching on a bike so please allow for stupid questions. I just figured out that part about the airbox, sorry I will check when I get home, I can be a little slow. Just got back from dealer and part is ORDERED, ya they suck.

Post by **Indawoods** » 02:19 pm Dec 22 2006

Take the carb off... leave the carb assembled.

radonc73 · Post by **radonc73** » 02:24 pm Dec 22 2006

You could look down the throat of your carb, wick it open to ensure the needle doesn't completely clear the needle jet (what it regulates pretty much).

Should I check this before taking carb off or is this part of what CC is trying to tell me?

canyncarvr · Post by **canyncarvr** » 02:34 pm Dec 22 2006

Re: '..please allow for...'

We're doin' alright, aren't we?

It's helpful to ask/answer one thing at a time, else it's easy to get confused.

Like....I don't know what your 'airbox' reference is about. When did we talk about your airbox? Never that I recall.

Back to this 'one thing'.

With m0rie asking about needle length, I wondered myself if for some strange reason the needle tip (the end away from the slide) was getting hung up on the jet block because it is being pulled OUT of the jet block.

So..as Inda says, take the carb out of the boots. Leave it completely assembled. If you have to take the cap off to GET the carb out (probably not in your case..it's true in some cases), put it BACK ON when you get the carb out.

Now..you're holding the carb in your hand, looking down the intake bell. Twist the throttle wide open. Watch the tip of the needle. What do you see and where do you see it.

The tip of the needle should NOT be pulled completely out of the jet block. The jet block is the carb assembly that has the needle jet in it..it's the thing you see the needle moving in and out of as you operate the throttle.

The answer to the question is:___________________________

radonc73 · Post by **radonc73** » 02:57 pm Dec 22 2006

I didn't know if you left the carb on to check the needle/ jet block question so it would be in normal position. I assumed that the airbox being removed would be the way if I didn't take the carb off, but can now see I will not be able to get the look I need without removing carb.

canyncarvr · Post by **canyncarvr** » 03:03 pm Dec 22 2006

Amen.

radonc73 · Post by **radonc73** » 07:46 pm Dec 22 2006

The answer is.....I took the carb off and the needle stayed in the jet block.

KDXer · Post by **KDXer** » 12:52 am Dec 23 2006

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radonc73 wrote:The answer is.....I took the carb off and the needle stayed in the jet block.

You are twisting the throttle wide open when looking of course ??

Does your needle look like this ??

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KDX 250 throttle compatability