Mikuni TM40 (HS40) Flat Slide 40mm Pumper Carburetor

Additional Information

• Hola me serviría este mikuni para una suzuki dr 600 sn41a del año 87

  This carb is an aftermarket carburetor and not designed as a direct replacement for any original equipment carburetor, including the DR600. However, it is possible that it can be adapted to work on that motorcycle. Listed below are a few things you need to consider when attempting a conversion:
  
  1. What size is your current carb? You want the carburetor you select to be approximately the same size as your current carburetor. Too big a carburetor will not make you bike faster - it will make it run worse. You will, more than likely, also have to experiment with the jetting to get the bike to run optimally.
  2. Will this new carb fit in the same place as the old one? Check the dimensions of your current carb and compare it to the dimensions in the listing. Size is important!
  3. Will this carb fit your manifold and air filter boot? This carb has a 44mm spigot that fits into a rubber manifold adapter that attaches to your manifold. The DR has a rubber manifold adapter as well, but you need to check your current carb to see if the spigot (the part that fits into the rubber adapter on the manifold) is the same as this carburetor. If not, an adapter will have to be machined. The intake bell on this carb is 55mm. That is the part that mounts to the rubber boot on your air cleaner. If it's close in size, you can sometimes find ways to easily adapt this boot to fit. It is not as critical as the intake spigot.
  4. Will your throttle cable work? This carb uses a This carb uses a dual push/pull style cable. Can your cable be adapted to work with this or will you need a aftermarket throttle and cable as well?
  5. Will you be able to get to the choke and idle adjustment screws? If not, we sell a remote cable that is 8-10 inches long. You might be able to mount this to provide easier access to the choke.
  
  These are things that must be taken into consideration before buying an aftermarket carburetor.
  

  Answer by: rick c (Admin) on Jan 8, 2018 11:38:00 AM

• I have a highly modified 1954 Indian Woodsman. As you may know, this was built by Enfield, 500cc single, 26 hp, but mine is 612 cc with flowed head, racing cams, huge titanium valves, etc, 52 hp give or take, and yes, I know, I'm crazy, but you should see it. I'm running a 1 1/2 inch Amal GP racing carb with matchbox float. The bike's performance is amazing, the Amal looks and works awesome, with great throttle response, but there is no idle circuit on that carb, and of course, no accelerator pump. I'm considering a TM38 or TM40-6 pumper. Any ideas or suggestions? Adapting and manifolding not a problem for me, but I'd need a push pull throttle, correct?
  Thanks, Doug

  Sounds awesome! We would love to see some photos or video of it. For the TM40-6 you may want to use a push/pull cable setup. It is not an absolute requirement, because the spring tension to return the slide back to idle is adjustable and can be made to be quiet strong. The TM38 would not accept anything other than a straight pull cable. A lot of the decision process will boil down to what you really want out of it. A smaller carburetor will give you better low end to mid range, while a larger carburetor will sacrifice some lower/mid power to improve top end. I think for the most part, a pump equipped carb might be a bit overkill, but if you want top end performance, the TM40 will give you that, and the pump will help with the throttle response. Being such a nostalgic bike, it will be hard to beat the looks of an Amal GP, but the Mikunis are very tunable and reliable.

  Answer by: Web Support (Admin) on Nov 15, 2017 3:17:00 PM

• I just installed the tm40 on my dr650 and the spring tension is way too stiff when I pull the throttle. Can you tell which post on the bell crank has the least tension; either the rear post or the front/forward post? My spring is hooked to the rearward post. Thanks in advance.

  Bob,
  I have found that the carb comes from Mikuni with the return spring set to the heaviest position. If you hold the carb with the intake bell to your right (the part that attaches to the air cleaner), the return spring should be facing your body. If you look down at the carb, you will see that the return should be on the the far right stud on the bell crank. There are only three positions. If you take a small, flat blade screwdriver, you can push the return spring off the far right stud, and it will jump to the center stud. And then you can repeat that process to put it on the far left stud which will have the lightest return pressure. I have found the far left position to be adequate for most motorcycles. But this is subject to personal preference.

  Answer by: rick c (Admin) on Mar 20, 2017 9:08:00 AM

• Do you guys pre-jet these and set them up based on ones exhaust, altitude etc? I have an XR650L I'm looking to put this on.

  We do not offer them pre-jetted at this time (7/12/2016), but we did just recently purchase a 2009 XR650L that we are going to use to configure a carburetor kit. We have not dug into it much yet, but it appears that you will need a custom push/pull cable set, or possibly modify the stock cables. You will also need adapter rings made for each side of the carburetor so that it fits into the intake manifold, as well as the airbox side connector. As for jetting, we have not gotten that far, so I dont have any information as to a good starting point.

  Answer by: Web Support (Admin) on Jul 12, 2016 5:46:00 PM

• Hi, what AP nozzle size is fitted to the TM40 from the factory? Cheers Michael

  The Mikuni TM40-6 comes from the factory with a TM36/43-08 pump nozzle, which is size #70.

  Answer by: Web Support (Admin) on Feb 15, 2016 8:37:00 AM

• Hello, I recently purchased the TM40 for my XR650R. Says it's set up for my xr but came with extra jets. Are these for a modified motor or something? thanks

  We pre-install jetting for the XR650R, but due to different riding conditions and engine setups, we include the additional jetting for further tuning ability. If you are fairly close to sea level, with a stock engine, or slightly modified intake/exhaust track, you will likely be able to run the kit with just a few small adjustments of the fuel screw.

  Answer by: Web Support (Admin) on Aug 22, 2016 9:20:00 AM

• Do you pre-jet these currently for an 08’ XR650L? You didn’t in the past but that was 3 years ago. And if I buy one will it be a straight bolt up or do I need to buy adapters or anything else? Thanks!

  Yes, we offer kits for the XR650L. Here are links to the two versions. One has a body choke, the other has a remote choke.
  
  http://www.nichecycle.com/ncs/categories/carburetor/carburetor-kits/ncs650lb-honda-xr650l-tm40-mikuni-carburetor-kit-body-mounted-choke.html
  
  http://www.nichecycle.com/ncs/categories/carburetor/carburetor-kits/ncs650l-honda-xr650l-tm40-mikuni-carburetor-kit-remote-choke.html
  
  

  Answer by: Web Support (Admin) on Apr 29, 2019 10:35:00 AM

• Hi I'm looking at fitting on of these to my Yamaha xv750, what else would I need? Thanks Chris

  At the very least you are going to need an intake manifold, and likely a flange adapter depending on the manifold you go with. Other concerns would be the cables, an air cleaner, and proper tuning of the carb.

  Answer by: Niche Cycle (Admin) on Jun 22, 2015 9:57:00 AM

• Will the tm 40 work on a 1996 ktm 620 rxc ? in place of the edelbrock quicksilver. And what cable to use?

  Unfortunately we don't have any solid information on using a TM40 carburetor on a KTM. It could require cables, as well as manifold/adapters aside from correct jetting.

  Answer by: Web Support (Admin) on Dec 28, 2015 10:19:00 AM

• I recently purchased for a 2006 xr650l. It runs good, but has a slight hesitation just off the bottom. Seems a liitle rich on idle as it will load up a little and puff out small amounts of black smoke until you clear it out. What would be the first adjustment I should try. It will idle smoothly and consistently once warmed up and cleared out. Just want that initial hit to be instant, not stumbly. Starts up almost instantly.

  If your air filter is clean, and flowing properly, then the first adjustment I would make is the fuel mixture screw. Turning it inward will reduce the amount of fuel on that circuit. If that doesn't quite do it, you will then need to install a small pilot jet.

  Answer by: Web Support (Admin) on Sep 3, 2020 8:44:00 AM

• I have a 2007 Honda XR 650L and have read about switching to a Mikuni TM 40 pumper Carb and a Mikuni Quick Throttle, does that sound like it will bolt up and work well?

  Dan, our TM40 kit for the XR650L offers a great performance boost. I don't know much about the MIkuni throttle (if it really is Mikuni-made) but unless you're racing, there isn't that much of an advantage to using a quick throttle over the Honda throttle. But I'm sure it would work. I can't remember if the starter button is integrated into the stock XR650L throttle, but if it is, you'll need to come up with a starter button if you choose to use the Mikuni throttle.
  I highly suggest using our kit. With the kit it's a bolt-up and go operation. If you buy just the TM40 by itself, you'll have to get adapters machined (no one sells them), you have to determine the correct jetting and then, you have to come up with lengthened throttle cables. Our kit will save you time and money! Please see the link below:
  http://www.nichecycle.com/ncs/categories/carburetor/carburetor-kits/ncs650l-honda-xr650l-tm40-mikuni-carburetor-kit-remote-choke.html
  You can contact me if you have any other questions at rick@nichecycle.com

  Answer by: rick c (Admin) on Jun 18, 2019 11:57:00 AM

• Does the tm 4o mikun pumped come preheated for a dr650
  

  It does not come specifically jetted for the DR650, but its really close. If your bike is stock, you will probably need to drop the main jet to a 135-140, and rise the pilot jet to 22.5-25. The needle, and the needle jet should be ok, but it all depends on the bike, and the riding conditions.

  Answer by: Web Support (Admin) on Nov 10, 2015 4:33:00 PM

• will this fit a 1995 xr600

  Its a popular carb for the XR600, but we have not attempted an install ourselves, so I don't have much information as to what its going to require to get it installed, and running properly.

  Answer by: Web Support (Admin) on May 3, 2021 2:48:00 PM

• Will this fit a 1990 dr 650S ? Thanks

  This carb is often used on the DR650, but its not install ready. You will need to fit it to the manifold, and airbox with adapters. You probably will need to modify the stock cables, or have custom cables made. You will also need to adjust the jetting. We plan to put a kit together for this model, but that wont happen for a few months (late 2020)

  Answer by: Web Support (Admin) on Aug 18, 2020 10:38:00 AM

• Will this fit a 2011 Suzuki Dr650

  The TM40 is a very popular choice for the DR650, but it is not a direct replacement. An adapter is needed for the air filter boot. It will also need to be re-jetted, and you might need different throttle cables. We were working on a ready to install kit, but the project has been put on the side until we get our dyno set back up in our new testing location.

  Answer by: Web Support (Admin) on Jun 23, 2020 11:25:00 AM