• Fitting the Mikuni VM26-606 without paying more, or hassling with fabrication.

  • Have a technical problem? Ask here.
November 2019 Forum Retirement
Due to lack of extra personal time (and too much spam), I'm retiring the forum and setting it to a read-only state. No new registrations or posts will be accepted as of 11/09/19. However, all information will stay up and searchable. If you spend a few minutes searching, you'll find the answers you're looking for. We may re-open the forum next spring.
Have a technical problem? Ask here.
Forum rules: Help us to help you, by reading our information in this Forum thoroughly and performing the tests within to pinpoint your issue.
 #11175  by Travis @ Buggy Depot
 Fri Oct 27, 2017 12:37 am
The space between the engine and swingarm on most 150cc models wasn't designed for larger carburetors. That's not a problem though, the VM26-606 just requires some technique and a little finesse to install.

The VM26-606 fits at a very specific angle, and locks into place once you get it right. Once you do it the first time, it's much easier thereafter.

Some say risers are a good idea (they aren't), others will suggest that cutting and re-welding the frame is necessary (it's definitely not). Fitting the carb the way shown below is the most practical, reliable, and hassle-free method of installation.

Here is my VM26 install, been running this way for 5 years or so after trying several other methods that didn't work as well.

Image

Image

The gap between the manifold and intake tube is necessary. This should be the last step. Tighten everything else first, then align the carburetor where it needs to be. When it's just right, tighten the clamp down to lock everything in place.

Expect the drain barb on the bottom of the carburetor to make contact with the engine hanger bolt. This is normal and won't harm the barb. An unintended benefit of this tight fit is that the carburetor is stabilized against vibration and can hold a lower, more stable idle than would otherwise be possible.

Image
Attachments
IMG_0067.jpg
IMG_0072.jpg
IMG_0079.jpg
 #11559  by Rugernation
 Wed Mar 14, 2018 6:06 pm
I recently purchased the Mikuni carb and aluminum intake for my dazon raider 150 classic. With the aluminum intake the carb lined up directly in front of the chassis cross bar with no way to hook up air filter. Using the stock intake I was able to install like your pictures show but the aluminum intake angle is different. Will this carb work properly with the stock intake?
 #11567  by myvt365
 Thu Mar 15, 2018 7:40 am
to answer your question yes it will work. How well that depends on how you will jet the carb. I have spent a lot of time and effort dialing in my Vm26-606. Ok so the problem with factory air boxes is the volume of air that is available when the carb is requesting it. So when you step on the throttle the needle and slide are going to open and pull in the air to get the more throttle requested for acceleration. running a factory air box you will be running rich out of the box I can almost guarantee this do to not havening enough air to match the bigger jets. Factory VM26 comes with a 22.5 pilot and 190 main jet this will also be determined depending on elevation and other mods that are done to the unit. I think im running a 200 main and 30 pilot at this point I can double check for you im also at 1050 ft above sea level and running unit with a full flow exhaust. Also in one of Travis's write ups its shows how the factory airbox is susceptible to passing dust which can cause what we call dusting in the industry. That's basically where dirt come past the filter and will media blast the cylinder walls. All in all it will work but your going to have to jet the carb for that. It is worth it modify if you need to make the bigger carb work the reliability of Vm26 far exceeds that of the factory carb and dieing out.
 #11573  by Rugernation
 Thu Mar 15, 2018 9:24 pm
Thanks for the response, I have the uni filter on the carb but have to use the original plastic intake manifold due to the different angle of the aluminum manifold. In the carb description it says the aluminum manifold is necessary but if jetting it properly will work that's where I will start, I am at about 1450 ft. I see the main jets on your site but where is the best place to get the pilot jets?
 #11579  by myvt365
 Fri Mar 16, 2018 8:23 am
as far as being higher in elevation then me you are going to need a richer jet have you tried to start id it you maybe at a good starting point with the rich jest already in the carb. install the carb and try to start it. Turn the fuel screw all the way in back it out 1.5 turn and get the unit running if it will run post back up results and I can try to help you after.
 #11581  by Sportsman850
 Fri Mar 16, 2018 9:02 am
On the VM mikuni carb, the idle screw can range from 3/4 of a turn out, to 1 1/5 or more. Your pilot jet size will impact the screw turns out. You're looking for a response in throttle right away. Pilot jet controls idle to 1/4 throttle, the needle jet controls 1/4 -3/4, and your main jet will start to kick in at 1/2ish but is in complete control at 3/4 to full. A good way to tell if you're lean or rich is to hit the choke while running. If you see no change, or improve you're lean. If you start stalling you're in the ball park.

Now idle can be influenced by clip position on the needle, but not by much. If in mid range you're boggy from being lean, move the clip down thus moving the needle up. It will richen the fuel/air mixture. Do the opposite if you're already rich. This is for mid range only. If doing this has no bearing on it either way. Your needle jet is wrong.