01 CR250 cutting throttle slide

[VAL]

Me again.
I have been working to find nirvana when it comes to the jetting on my 01 Cr 250. I bought the JD jet kit and am a bit concerned with how lean I had to take it using his needle but the plug chop shows I’m ok when its run wide open.
In the jet kit, I was given only a 32.5 pilot jet. This proved to be too rich so I went back to my 25. I have the clip at the top (#1) of the “warm” weather needle with a 380 main and I still have a bit of a “chug chug” when I am at the very bottom end. This also effects the idle. If you wrap the throttle, it comes back to idle right away with the “Chug Chug” and then starts to drown after about 10 seconds. I have the airscrew out 2 turns and the throttle stop in pretty far in. So now with all that said comes my question. Has anyone out there had any luck with filing 1 mm off the bottom air passage of the throttle slide? I have heard of this “back in the day” but I find it hard to believe in this day and age that the manufactures still have these issues. Or maybe it’s just me.

[The Baron]

Pro Circuit had the set-up for the CR's back when. I do remember something about them changing the slide cut but I can't remember what they did exactly.

Here's their jetting spec page. My buddy had fits with his '01 until he sent his carb in to PC. After he got it back he didn't have to mess with it ever again.
[Only registered and activated users can see links. ]

[krzywhiteboy]

You will be hard pressed to get that bike to run its best and to idle well. It just does not go hand in hand with that carb. Turn your air screw in all the way and back it out only 1/4 turn then work your way out more. I have NEVER been able to get a CR to run good with the air screw more than 1and1/2 turns out. That is just my experience with them.

[VAL]

Originally Posted by krzywhiteboy

You will be hard pressed to get that bike to run its best and to idle well. It just does not go hand in hand with that carb. Turn your air screw in all the way and back it out only 1/4 turn then work your way out more. I have NEVER been able to get a CR to run good with the air screw more than 1and1/2 turns out. That is just my experience with them.

Oh Ive done the entire carb tune deal. Dont get me wrong the bike runs great and I did have response from the air screw even at 2 turns out. I'm just trying to make it perfect. The other problem is Im setting it up at sea level and when I go to the upper desert it will be rich again.

[junteschan1]

VAL,
I have the pro circuit set up on my 01cr250 including the nozzle s-7 installed. You might want to try this as an alternative to what you already have.
So far i feel the bike runs way much better than the factory specs....
Good luck.

Originally Posted by VAL

Me again.
I have been working to find nirvana when it comes to the jetting on my 01 Cr 250. I bought the JD jet kit and am a bit concerned with how lean I had to take it using his needle but the plug chop shows I’m ok when its run wide open.
In the jet kit, I was given only a 32.5 pilot jet. This proved to be too rich so I went back to my 25. I have the clip at the top (#1) of the “warm” weather needle with a 380 main and I still have a bit of a “chug chug” when I am at the very bottom end. This also effects the idle. If you wrap the throttle, it comes back to idle right away with the “Chug Chug” and then starts to drown after about 10 seconds. I have the airscrew out 2 turns and the throttle stop in pretty far in. So now with all that said comes my question. Has anyone out there had any luck with filing 1 mm off the bottom air passage of the throttle slide? I have heard of this “back in the day” but I find it hard to believe in this day and age that the manufactures still have these issues. Or maybe it’s just me.

[VAL]

Originally Posted by junteschan1

VAL,
I have the pro circuit set up on my 01cr250 including the nozzle s-7 installed. You might want to try this as an alternative to what you already have.
So far i feel the bike runs way much better than the factory specs....
Good luck.

Thanks for the input
What is the nozzle s-7? Do you mean the slide?

[junteschan1]

VAL,
The nozzle is where the slide's needle goes thru inside the carb....
the removable brass tube where the main jet is screwed on its very bottom.
OE spec is an s-9 and pro circuit spec calls for the s-7 size
Let me know how you like it after doing this mod.

Originally Posted by VAL

Thanks for the input
What is the nozzle s-7? Do you mean the slide?

[VAL]

I got the part number for the nozzle off the internet, there was only one selection, and called my local Honda dealer. The guy at the parts counter said that his computer showed only one item as well. Is this a special Pro Circuit part?

[junteschan1]

Originally Posted by VAL

I got the part number for the nozzle off the internet, there was only one selection, and called my local Honda dealer. The guy at the parts counter said that his computer showed only one item as well. Is this a special Pro Circuit part?

Hey VAL,
No its not a special pro circuit part. Its a mikuni carb aftermarket part per WPS (Western Power Sports) Catalogue issue 2007 on page 500 at the middle left portion of the page. Ask the dealer if he has this catalogue.
Good luck.

[VAL]

Originally Posted by junteschan1

Hey VAL,
No its not a special pro circuit part. Its a mikuni carb aftermarket part per WPS (Western Power Sports) Catalogue issue 2007 on page 500 at the middle left portion of the page. Ask the dealer if he has this catalogue.
Good luck.

Couldn't ask for more specific help than that.
Thanks

[junteschan1]

Originally Posted by VAL

Couldn't ask for more specific help than that.
Thanks

saves time......just need your feedback......

[808hondacrguy]

I gave up on my mikuni,chucked it in the lake,and installed a keihin from a 99 CR250.This was THE best thing I ever did to my bike.

[01hondaman]

I tried just about everthing to get mine to run right and it always ran like crap in somewhere in the throttle range. paid 150.00 to service honda for a brand new keihin carb and the thing runs sweet. never fouled a plug again.

[YZhallsme]

VAL you should have got an s-4 nozzle with your JD kit for your 01', if you bought it from him contact him and ask about it, I did and he sent me one. If I remember right the same kit covers 01' thru 07', only the 01' thru 03' use the s-4 though.

[junteschan1]

Originally Posted by YZhallsme

VAL you should have got an s-4 nozzle with your JD kit for your 01', if you bought it from him contact him and ask about it, I did and he sent me one. If I remember right the same kit covers 01' thru 07', only the 01' thru 03' use the s-4 though.

YZhallsme,
glad to read your reply.....your jd kit w an s-4 nozzle, my first to hear this mod.
How is the engine response....much better than stock? more crisp exhaust note?
appreciate your further accommodation.
thanks,

[VAL]

Originally Posted by YZhallsme

VAL you should have got an s-4 nozzle with your JD kit for your 01', if you bought it from him contact him and ask about it, I did and he sent me one. If I remember right the same kit covers 01' thru 07', only the 01' thru 03' use the s-4 though.

I will check the package again, but I dont remember seeing it. Thanks for the heads up.

[YZhallsme]

Sorry VAL I can't comment on the JD kit as I havn't installed it yet. My kit did not come with the s-4 either but I had read at another site that it should have, so I contacted JD via e-mail and asked him about it. He said that they should have asked me the year of my bike at the time I ordered as they are supposed to send the s-4 nozzle with the kit for the 01' thru 03' models. Again If you bought your kit from him I'd recomend you talk with him about the s-4 and any other concerns your having. I did and I have to say he answered all my questions in a timely manner and had the nozzle headed my way the next day. I'd say his customer service is first rate!

[VAL]

Didnt find the S4 nozzle and so I called JD. I was also concerned that when I purchased the jetting kit it was for an 01-07, even showed on my e-mail invoice, but when I looked at the site the kit I purchased was for an 04-07. When I called, I was told that they recently separated the kits and thats why I didnt get the nozzle. Any who, they are sending the nozzle today. Will let you know how it works when I get it.

[junteschan1]

Originally Posted by VAL

Didnt find the S4 nozzle and so I called JD. I was also concerned that when I purchased the jetting kit it was for an 01-07, even showed on my e-mail invoice, but when I looked at the site the kit I purchased was for an 04-07. When I called, I was told that they recently separated the kits and thats why I didnt get the nozzle. Any who, they are sending the nozzle today. Will let you know how it works when I get it.

VAL,
You mentioned you received the jet needle included in the kit. Do you have the needle part number (inscribed on it), so i can order & try it likewise for comparison....many thanks of course.

[VAL]

Originally Posted by junteschan1

VAL,
You mentioned you received the jet needle included in the kit. Do you have the needle part number (inscribed on it), so i can order & try it likewise for comparison....many thanks of course.

Ill take a look but I think that these are made special from JD. They have either a red dot on the to for the "warm" needle and a blue dot for "Cool" needle.