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MarkfromNC

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About MarkfromNC

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    TT Newbie

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    North Carolina
  1. MarkfromNC

    KLX140L Case Splitting & Rebuild (DIY)

    Story with a great ending. Best way to learn about anything mechanical is to get your hands dirty. Geez, those quoted labor prices makes me believe I went to school for the wrong thing.
  2. MarkfromNC

    Klx 140 jetting

    There are others here who can give you better advice on jetting that big bore than me. I would contact whoever makes the kit for a starting point. Planning to install a Mikuni VM26-606 myself this Spring on my 140cc bike and having difficulty finding good info on a starting point for jetting. The only complete kit for fitting a different carb I've seen is the Engines Only kit I mentioned. There are posts from others here who installed a larger carb to the factory intake and used a 2" piece of pipe to lengthen the air duct between the carb and the airbox. Search for KX65 carb to read more. Something else to check out is the air duct off a KLX150. The KLX150 is basically the same bike sold in Asia but street legal. It has a 24mm Keihin PWK derivative carb requiring a longer air duct. SXParts has that air duct for sale on Ebay right now, and the duct is obviously longer in the picture.
  3. MarkfromNC

    Klx 140 jetting

    My guess is you could handle a 26mm with 170cc no problem. BBR used to offer a kit on their website for big bores with a 26mm Keihin. They used a Keihin carburetor originally designed for the XR200. They still list all the parts needed for the swap and say they will manufacture the adapter flange periodically. Frank Nye from Engines Only has a kit available with a 28mm Mikuni flat slide for the KLX140's. Its $399 but includes the carb, new intake manifold, K&N pod filter, new throttle cable, etc. I found a formula a while back for determining recommended carb size for these these types of engines somewhere (can't remember where now), but looking at posts here and elsewhere it seems to make sense. Take the carb size & divide by two. Square your result to determine the engine displacement in cc's for good performance with stable jetting: 20 mm → 100 cc 22 mm → 120 cc 24 mm → 145 cc 26 mm → 170 cc 28 mm → 200 cc 30 mm → 225 cc 32 mm → 255 cc Not saying you can't make bigger carbs work, but staying in this range is supposed to make tuning much easier.
  4. MarkfromNC

    Klx 140 jetting

    The stock carburetor is tiny, a Keihin PB20. It is really too small to feed the stock motor. I have PM'd folks here who all told me adding a 24-26mm carb to the stock bore engine made a huge difference. I think you would be disappointed if you tried to run it on a big bore engine. Based on my recent experience with this bike, I would reconsider keeping the factory exhaust. The cheapest aftermarket I could find was a Pro-Circuit. With an eBay 15% off special a few weeks ago I scored the exhaust for $201. The Pro-Circuit pipe starts with a larger internal diameter than the factory pipe and has two steps to larger size before the muffler. With the spark arrestor it isn't obnoxiously loud, either. My "dyno test" is a drag race against our other bike. Before the exhaust it consistently outrun me. With the Pro-Circuit and mandatory re-jet, I easily run away from the other bike now. Just proved to me the factory exhaust strangles the KLX140L to death.
  5. MarkfromNC

    Klx140L junker build

    Is that a KLX85 front fender & number plate or aftermarket? If aftermarket, did the color match the OEM stuff?
  6. MarkfromNC

    2018 crf125fb help

    This one would ship from Australia, but I know I've seen them available from a couple of sources-- https://gearfactormx.com.au/product/honda-crf125f-front-sprocket-2014-2016 Update us on how it works for you.
  7. MarkfromNC

    2018 crf125fb help

    I totally agree with you and believe it can be done. This bike was built so a kid who had never ridden could ride without stalling the engine. They succeeded in that endeavor-- my son had never ridden anything with a clutch and was riding independently in about 2 minutes! CRF125FB front gear has 13 teeth, rear gear has 49 teeth. Chain is a 428x118. With some calculations you should be able to improve the situation. The rear sprocket on the smaller wheeled CRF125F has 46 teeth. I have seen 14 teeth front sprockets online....may be able to find other options with a little Google time.
  8. MarkfromNC

    '18 CFR125FB - A/F and gearing tweaks.

    Edit: Yuu beat me to the question...what is the high flow version? Don't know the head pipe diameter of the FMF, but the stock is a tiny 18mm. The Yoshimura pipe I put on my son's 125 starts at 25mm and goes larger from there. I'd assume a big bore would need a large head pipe.
  9. MarkfromNC

    '18 CFR125FB - A/F and gearing tweaks.

    The 6Sigma kit will come with the screw, drill bit, and instructions for the pilot fuel screw.
  10. MarkfromNC

    Crf125f

    Definitely there, definitely in business. Frank really knows his stuff!
  11. MarkfromNC

    '18 CFR125FB - A/F and gearing tweaks.

    mlatour is correct. Carefully drill a tiny hole and it should pop out with a screw. Installed an exhaust on my son's, and used a 6Sigma jetting kit. With the jets in the kit, it took a #40 pilot jet, #117.5 main jet, and two shims under the stock needle (I'm basically at sea level). It's like a different machine now-- much faster than our stock KLX140L. The intake seems to be pretty well designed...much better than the KLX140. The bike uses a Keihin PE20 carburetor. I have a PE24 from a CRF150F to go on the bike, just haven't had the opportunity to swap. Frank Nye over at Engines Only didn't really recommend any gearing changes when I spoke with him last, but I would think something a little taller would help. First gear is super steep to keep young riders from stalling.
  12. MarkfromNC

    Frame touch up paint?

    Picked up a 2011 KLX140L and in the process of repairing and personalizing. The frame has the typical wear and tear from riding boots, plus some paint gashes from being dropped or banged around. Has anyone found a source for a spray paint to match the factory frame paint?
  13. MarkfromNC

    KLX140G Performance Feedback Wanted

    I picked up a seldom ridden 2011 KLX140L a couple of weeks ago, and going through the same thoughts myself. I know it needs an exhaust, but cannot decide which one. Based on what I've read, I don't know that the Pro Circuit has a large enough head pipe to help top end. The FMF uses the same size header as stock (maybe the step design will help the FMF and Pro Circuit?). BBR no longer makes a pipe for the KLX140's. The Two Brothers exhaust used a head pipe that started at 28mm external diameter (is that too big?). SXParts sells two exhaust systems, one has a 26mm internal diameter head pipe and the other a 29mm internal diameter...but know nothing about this exhaust and if it will be ridiculously loud or not. I cannot find any information about the diameters of the Yoshimura pipe....but the one pipe I bought from those guys really woke up my son's CRF125. The little Keihin PB20 carb on this bike was apparently borrowed from the LML Star 200, a scooter built in India. I cannot find anything else that uses this carb. But apparently the carb is what really holds this back this bike. BBR used to make a carburetor kit using an XR200's 28mm carb...but my conversations with them said this carb has a bog at 1/4 throttle that is impossible to tune out on a stock bore. They do not recommend this carb unless you go with a big bore kit. Engines Only has a$399 kit with their custom intake, a 28mm Mikuni flat slide carb, throttle cable, K&N pod filter and an outerwear cover. He said he can tune the carb to work for stock bore, big bore, or to use the factory air box. The two posts I have found online about Engines Only's kit were rave reviews about how much it helped this bike wake up. Lot of people here swap for the KX85 carb, but the "carburetor duct" hose connecting to the air box is too short. I did find out that SXParts sells the KLX150 carburetor duct on eBay, and it is apparently a couple of inches longer than the carb duct on the KLX140 (KLX150's used a Keihin PWM24 carb and different intake). Geez, I think too much about this stuff. Any advice anyone can add would be appreciated.
  14. MarkfromNC

    Is the KLX 140 a decent bike?

    Check out the KLX140L instead of the regular KLX140. The 19" tires make it a tad taller than the CRF100 (30.9" vs 31.5"). I just picked one up for myself to chase my son on his CRF125FB.
  15. MarkfromNC

    2015 CRF 125 jetting and power mods

    I am currently tinkering with my son's CRF125FB. Installed a Yoshimura exhaust, pulled the air snorkel and rejetted. It made quite a difference-- it pulls through the rpm band instead of laying down as it did from the factory. I just picked up a 24mm carb from a CRF150F to rebuild and install.
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