Jump to content
Sign in to follow this  

xr 250 mikuni tm 32 jetting?

Recommended Posts

hey i have 2001 xr 250r with a new mikuni tm 32 from xrs only i ride at around 1500-2000 feet, have a white bros slip-on, grounded out header welds removed snorkel etc. When cold if you dont start it first couple kicks it floods quickly and is impossible to start unless rollstarting. The bike also bogs more on accelaration then stock. any ideas how to solve these problems? jets in the carb at the moment are 195 main and 35 pilot spare jets i have are 200,190 main and 30,40 pilot

thanks

Share this post


Link to post
Share on other sites

it was quite black when i pulled it out to clean it when it flooded. the bike revs clean from about 1/3 throttle to max rpm, i might try the leaner pilot?

Share this post


Link to post
Share on other sites

Play with the fuel screw first. Get it started and warmed up as best you can, then turn the screw in. If you can seat it without any change, go to a smaller pilot. Once you can get the idle to change when truning the screw either way, you got the right pilot. Then, turn the screw in until the idle changes and then out til it changes. Count your turns, and whatever you come up with, the middle is about where you need to set your fuel screw at. And check your plug regularly.

For the main, get the pilot dialed in first, then start doing plug tests (use a new plug or a very good cleaned up one). Warm up the bike, then do a hard pull through all the gear, then shut the bike immediately. Check the plug for color. White is lean, black is rich. Try and get the lightly toasted marshmellow color. If you get brown or so, you can play with the needle height by moving the clip. Moving the clip up is leaner, down is richer.

Share this post


Link to post
Share on other sites

I get what you are saying about the bogging for the first 1/3 of throttle. Mine just sputtered pretty much. I couldn't understand why I was so rich when according to the "average" set up that was sent (jetting and elevation), it seemed if anything I might would have been lean. But, with the black spark plug and running conditions it was too rich. I think realistically it was set up for a big bore. Luckily the smaller jets seem to work for me and the clip is next to last at the top. Plug is a good amber color. Being that I am using the smaller jets at 500' I would think you are going to need smaller than the ones sent to you. I am a rookie so it is just hypothetical. I did some researching on the web and lots on carb tuning info out there. It can be figured out by how the bike runs, what part of the throttle and plug. Best thing I read was, "if you have a choice, it is always good to be a little rich". Which is why I was so cautious to go with the smaller jets, but, they worked.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

  • Similar Content

    • By 661Bran28den661
      What’s up guys. Totally new here picked up an XR400R I live in the desert so I’m riding often and enjoy it. But I am having some issues with my  01 XR400R. I brought it out this morning for a putt and it seems to be choking up in the top of second. Like a bog an go bog an go. First seemed fine and third I didn’t make it high enough into the rpms to see. Before I brought it back to the garage. Yesterday I also changed the air filter back to an uni. I had seen the other one had a hole in it and the box was dirty gunned up and oily. I removed the airbox gave it a good clean out wiped everything down very well put a piece of screen over the snorkel Or where it used to be I should say. “Lightly oiled the filter.Also the spark arrester an tip for the bike it did not come with I ended up making one with a piece of flat steel and drilling holes. Whilst doing this. I found also a crack in the pipe. It almost sounds as like there’s a vacuuming or whistle? When revving.The first one I had made worked fine I had no issues. This one I am wondering maybe if it’s a cause of a little too much back pressure.So I’m assuming it’s either a Carb or exhaust problem. Or something that could totally be minuscule. Or major issue. Would definitely like some second opinions and any advice would be greatly appreciated. Thanks guys! 
      TWISTIN THROTTLES & CRACKN BOTTLES


    • By ddickinson
      My lanky 14 year old boy started showing an interest in riding MX/Off-Road so I sourced the best beginner friendly, yet dirt worthy, bike I could find: an Ol' Honda XR250R (2004). So far I've replaced a few clutch levers and perches with stock parts. That's gotten old and I'm looking to upgrade to an ASV or Torc1 type fold-able clutch/perch brake combo. Went to purchase online today and to my surprise there were no such parts listed for the XRs. I saw plenty of CRF/CRF-X choices and they seem to differ depending on generation. Obviously I can use nearly any perch/clutch combo as long as the two match; but I was wondering if anyone knew which of these levers was closest to stock? Also, will the first gen CRF250X brake lever work on the XR? These may be stupid questions to some; but I'd rather ask a dumb question than drop money on an ASV brake lever I can't use. Thanks for any help.
      #xr250r#hondaxr  
       
       

    • By TheLastByte
      Im currently in the market for an xr400r, and considering buying one that's had some heavy engine work done. The current owner claims to have bought it from a friend who's an XR enthusiast. The PO installed a big bore kit and high comp piston, as well as a xrs only pumper carb, rsw triple clamp, aftermarket clutch, street lights, and a whole bunch of bling.
       
      My main concern is the effect the upgrades will have on the engine's longevity. How much quicker will I be going through top ends with the setup on this bike as opposed to a stock setup, and should I be worrying at all about bottom end longevity as well? I wouldn't mind having to eventually redo the top end, but I don't want to deal with a race bike type top end rebuild schedule on an XR. 
      Is there anyone here who's running a bike similar to this one who can give some advice? 
    • By Ralph303
      I have a 2001 Honda XR400R. It has a whirring/grinding sound in the lower end and a vibration in the top end. I pulled the valve cover and everything looks good. Decompression lever looks to be in order. Anyone know where I should start looking or just rebuild the whole engine. Ballin on a budget, but really love this bike. It looks like it’s new otherwise. Oil was jet black and thin. Thanks in advance! 
    • By junglePIG
      Hi, I have an Xr250r with a buckled/ wobbling front wheel, after trying to true the rim i have broken a spoke.
      I am wondering if it is possible to lace any 36 hole aftermarket rim to the oem hub, also will i need to buy an xr250r specific spoke set. also could i take a 36 hole rim from another front wheel and lace that up???? thanks
×