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  1. Grom doesn’t pull in 4th gear after Koso camshaft install

    Grom Performance
    Hello, Im new here and I apologize if this has been asked and answered already but I recently installed a Koso cam on my grom and 4th gear kinda sputters and doesn’t pull. Also all gears are slower in lower rpms until I hit over 6-7k. I know my timing isn’t off I checked and rechecked over and...
  2. FS: Finbro ECU, Cold Start Harness & PCX150 Injector

    Parts for Sale / Wanted
    Bundled together. Taken off running bike with zero issues. Great for basic bolt on mods to keep your bike running safe. Self adjusting ECU. $185.00 + Free Shipping - PayPal F&F / Venmo $185.00 + $8.00 Shipping Priority Mail - PayPal G&S Located in New Hampshire. Local pickup preferred but...
  3. Grom DCR Ported Head

    Parts for Sale / Wanted
    For Sale Head ported by DCR 34mm Port matched intake port to run a Koso 34mm Throttle body DCR Dual valve springs installed OEM sized valves Valve seals are new
  4. Help with EJK tuning koso 170 bbk stock head

    Grom Performance
    hello I am looking for some help on tuning my ejk that is running very lean Mods koso 170 piston and cylinder * stock head koso cam chimera intake 150 pcx injector Koso AFR hooked on stock sensor 93 premium gas numbers GRN 4.5 , YEL 7 , RED 8 , G/B 7 , Y/B 3.5 , R/B 5...
  5. Upgrading throttle body

    Grom Talk
    I'm thinking of swapping the throttle body and have a few questions: 1) Do I need to de-pressurise the fuel system to swap over the injector or just leave injector attached and then fit it after to the TB once attached? 2) Do I just pull the tps off and put it on the new one (The koso 34mm...
  6. New Honda GROM parts available

    Koso North America
    Increasing your GROM®'s engine power is one thing but this beast has to be fed with the fuel it needs. Koso’s High-flow injector is the essential part for your modified Honda Grom®! It has a higher fuel flow to meet the increased demand of your upgraded engine. For more information, visit the...
  7. Independence Day Sale

    Koso North America
    15% off on everything in stock Free shipping for all orders over $200* Go to to see our meters, parts & accessories. Enter Promo code USA15 From July 1, 2016 to July 4, 2016 *Discount and free shipping apply on total price before taxes and shipping.
  8. Spring Cleaning Sale

    Koso North America
    It's so much fun to play in the dirt but now it's time for the Koso North America Spring Cleaning Sale! Get an additional 50% on already reduced prices for clearance products by entering promo code MUD50 in the cart. Until the end of April 2016. Go to the Clearance section to see all our...
  9. New 2016 catalogs

    Koso North America
    We are proud to present you the new 2016 Koso North America catalogs! A lot of new and interesting products have been added to our line in order to enhance your riding experience. With the interactive table of contents and bookmarks you can now navigate easier through the products. We have...
  10. V-Twin Expo 2016

    Koso North America
    Dealers and distributors, we are all excited about this weekend’s V-Twin Expo in Cincinnati, OH! This will be the first time that we will be exhibitors at this show. We have many new products that we developed specifically for the V-Twin market. Come down and be the first to see our new meters...
  11. Best wishes for the holidays and a little gift for you!

    Koso North America
    We wish you a Merry Xmas and a Happy New Year! As a Christmas gift, we offer you a 15%* discount on all orders placed on our website. Use promo code XMAS at checkout. * From December 24, 2015 to January 4,2016. Orders will be shipped January 4, 2016. Not valid on clearance section. Holiday...
  12. Honda Grom 4V Head kit and 170cc Big Bore kit

    Koso North America
    This complete Honda Grom 4V Head kit and 170cc Big Bore kit is the perfect add‑on for all horsepower enthusiast looking for performance! All parts are made from High‑quality components for reliability and durability that allow you to put your mind at ease and ride with confidence. It includes ...
  13. See you at the AIMExpo!

    Koso North America
    Koso North America is proud to announce that we will be an exhibitor at the AIMExpo for the THIRD year! This event will take place at the Orange County Convention Center in Orlando, Florida from October 15th to 18th 2015. Stop by our booth # 465 to view our latest additions to the Koso family...
  14. Here comes the Blade License Plate Light!

    Koso North America
    Our constant desire to add new products to our accessory line has pushed us to develop a small, compact and easy to install license plate light. Its specifications, quality components and Ultra-bright LED lights are the reasons behind its DOT approval. This item is a must to customize your...
  15. Koso is proud to present you the new flip-book catalogs!

    Koso North America
    At Koso, we want your online experience to be easy, simple, and most importantly enjoyable. That’s why we’ve updated our catalog’s lay-out and features so that they correspond to the same quality that you expect from our products. You can now navigate easily through the products with the...
  16. Clearance!

    Koso North America
    We now have a clearance section on our website with up to 70% discount on selected items! Meters and accessories sold in clearance are subject to change and quantities are limited. Come back often to see new offers as more stuff will be continuously added! Visit clearance...
  17. Independence Day sale

    Koso North America
    To celebrate the 4th of July, Koso North America is happy to offer you a 15% discount* on all orders. Just use the promo code USA15 at checkout. Offer valid from July 3rd 2015 to July 5th 2015. Don’t forget the free shipping for all orders over 200$.* Visit us at for more...
  18. 5 days remaining for the Koso discount!

    Koso North America
    Only 5 days remaining to take advantage of the 10% discount on any purchase at ! Sales end June 30th, 2015. Promo code: GROM15
  19. Pair of KOSO flexible LED Turn Signals

    KOSO LED Turn Signals One pair of strong flexible LED turn signals that would survive most crashes. Made by KOSO ~ 84 USD + plus shipping ~ 8 USD by Airmail to the US / Canada Order here: Grom / MSX 125 KOSO LED Turn Signals