Mikuni VM24
After seizing the AR80 a few times after putting the kit on it, and spending money on a bunch of jets for my VM18, the jetting was still lean in the needle. The shitty part about VM18s is that their needle isn’t adjustable. You have to buy an entire needle set if you want to adjust it. So AJ gave me his Mikuni VM24. It has an adjustable needle and takes the same jets at the VM18 (also the VM series will take dellorto jets). Not only is it easier to tune, but it’s HUGE too. EXTRA BLASTO SPEED TIME!
Tonight I went to the shop and fabbed up an intake for it. The old intake was for a clamp mount VM18 and had a rubber coating on the metal plate that clamped onto the carb. I torched the rubber off and was left with a clean plate. The inner diameter was around 28mm, so i had plenty of room to work with.
Since the VM24 is a flange mount i needed to weld on a plate for the carb to mount onto and then weld a tube (AJ also gave me a Boss header ID:24mm so i chopped that up for the tube) from the old manifold plate to the flange plate. Shay had an intake riser for a gila kit with a hole already in it that was 24mm. Perfect. I drilled some holes into the riser plate to match the flange on the carb and welded it all together.
Disclaimer: I am terrible at welding. There were a billion holes in the welds so I lathered some JB weld onto the welds and sealed it up. The manifold is currently drying and i’ll be able to put it back onto the bike tomorrow and see if everything works out like i planned.
wait, so the vm24 also takes dellorto jets?? i’ve got a vm18 on my derbi and it takes dellorto, but i thought that stopped at 20 or 22.
sure does. you told me that it would last week, but i hadn’t touched the AR80 in a few weeks and had never tried putting a del jet in there. Last night i opened up the 24 and tried putting a del jet in. It fit perfectly. The 18 and the 24 take the same main jets. so i’m assuming all mikuni carbs that take the large round head main jet (N100.604) will be able to take the del main jets.