Replacement Carb comes with a 40 Needle?

[Nehrke]

So - have a new TBR7 & live in Denver - having some issues with bogging so I ordered the replacement carb and jets I see referenced on amazon (Hwbnde VM26 Carburetor). Got the jets as well.

Issue I am seeing is that when I cracked it open there is a 40 needle jet (I think that is the term) for the 2nd one. Seeing a few folks mention that should be a 25.

How big of a difference does it make? If I need a 25 is there a good source for them? What happens if I leave the 40 in?

Planning on going with a 105 main.

Not looking to win any races, got the bike mainly to run shuttle with the raft when fishing......but would prefer not to have to do this twice.

Appreciate any insight. Thanks!!!

[Deckard_Cain]

I have that exact same carb, I'm at 600ft elevation, using a bigger main of course, but that 40 pilot jet is too big for me. I'm quite rich at idle.

In recent discussions with more experienced tuners, a 25-27 is generally what everyone settles in with.

I just bought one from jetsrus.com. They're your best bet.

It uses N224.103 style Mikuni pilot jets.

[Goob]

Originally Posted by Nehrke

So - have a new TBR7 & live in Denver - having some issues with bogging so I ordered the replacement carb and jets I see referenced on amazon (Hwbnde VM26 Carburetor). Got the jets as well.

Issue I am seeing is that when I cracked it open there is a 40 needle jet (I think that is the term) for the 2nd one. Seeing a few folks mention that should be a 25.

How big of a difference does it make? If I need a 25 is there a good source for them? What happens if I leave the 40 in?

Planning on going with a 105 main.

Not looking to win any races, got the bike mainly to run shuttle with the raft when fishing......but would prefer not to have to do this twice.

Appreciate any insight. Thanks!!!

I am in Denver. I ended up with a 100 Main and 30 Pilot on my RXB150. Needle clip is in the center position. I was surprised that the Pilot ended up that big. Runs great in Denver, but when I had it up at 8500 Ft it really needed the needle clip leaned out 1 notch, but I got along by blipping the throttle when it loaded up. This was at constant throttle on flat sections of trail.

I have since replaced with a VM26-606 that I took from my CSC TT250. To my surprise, again, other than adjusting the idle and pilot screws, this carb works great in Denver on the RXB150.

So, my tune on the VM26 Flange mount carb on the 150 may just work fine for your 250.

Oh, and count on doing adjustments more than twice, unless my formula works. I had the carb off and on about 4 times. I did buy a replacement Pilot jet screw that has a knob on the end for adjustment, which makes it so you don't have to take the carb off to adjust that screw.