VM26 Carb fine tuning?

[Bill Hilly]

I have been having a little trouble eliminating a very low rpm, low throttle surge. My bike is a 2016 Hawk that had the carb when I bought it used. It had the stock airbox, and unmodified exhaust. It had a 110 main, and I'm thinking a 22 pilot jet .It ran great, but the mixture screw was out 4 turns. I removed the catalytic converter from the exhaust, and installed a Nibbi pod filter. I had initially installed a 115 main, and a 25 pilot, and set the mixture at 2 turns out. It ran fine, but at very low steady speed ,with the throttle just barely opened it had a slight surge. I thought it may have been too much main, so I installed a 112. It runs about the same as with the 115, but I found a flat tip bit that I can turn the mixture with while running, and when I turned the mixture in the idle speed smoothed out, and increased from about 1,500 to 2,000. I thought that took care of it, and it did fine going to town, but once I got in town, it ran way worse, and wanted to chug, and surge at low speed under very very light throttle. I turned the mixture back out, and it was back to the very slight surge at very low steady speed, and light throttle. As soon as I actually give it any measurable throttle it's fine. The pod filter that I have on it is very very free flowing, almost like having no filter. Could this be the issue? I haven't messed with the needle position. Could it be too low?,. Or too high? Thanks

[Megadan]

Originally Posted by Bill Hilly

but at very low steady speed ,with the throttle just barely opened it had a slight surge.

This right here is the indicator that your 25 pilot is just a bit too small. This is the exact reason I mentioned to order a 27.5 pilot jet. go back to the 115 main and install the 27.5 pilot. Needle should be ok in the middle slot or 1 down from there if necessary.

[Bill Hilly]

Originally Posted by Megadan

This right here is the indicator that your 25 pilot is just a bit too small. This is the exact reason I mentioned to order a 27.5 pilot jet. go back to the 115 main and install the 27.5 pilot. Needle should be ok in the middle slot or 1 down from there if necessary.

I canceled the jets that I had on order from Amazon, and looked at the jets on the Jet R Us place that you mentioned, but I couldn't find the 25, and the 27.5 together at what I thought was a good price. I found genuine Mikuni jets on eBay for around $8-$9 each including shipping. I figured I would try the 25 first. So I guess now I will order the 27.5. Thanks