I'm not sure where to look from here. Carb has been cleaned several times, float set, new intake boot, new air filter, fresh fuel, 132.5 main jet, 42.5 pilot jet, pilot screw at 3.25 turns. Starts quickly, warms up quickly. Will not accel from a closed throttle.

[video:youtube]https://youtu.be/02kTMu7SkrM[/video]

That 132.5 main jet is large. I'm assuming an XT225? 125 for the main and 40 for the pilot is usually stock. It might be interesting to return the bike to a "leaner" mixture to see how this affects hot operation. You'll want the leanest mixture that achieves acceptable performance.

TTR225, but the same Mikuni BST-34. It had a 130 from Yamaha, which is what the manual states is stock for both models.(?)

FMF's tip sheet recommended 130/40 (stock), so I went up a touch since I removed the snorkel from the airbox.

This bike came home not running. It had a hole worn in the diaphragm cover, some kind of mystery goop in the bowl, and a dry rotted intake boot.

Those items have been remedied.

With the pilot screw at 3.25 turns, it looks like I need a bigger pilot jet, but I don't believe that would cause this kind of bog, and sputtering mid throttle.

Your jetting is on the rich side. I tried a 135 main briefly and it produced a hesitation and miss at full throttle. I am running a #130 main, 42.5 pilot and fuel screw
3 turns out. Works great

Runs great at WOT, you just have to slowly twist to get the rpms up.

Get it to 2500, and it does great, it's just initially from idle, and at part throttle. Trying to get on the throttle in a turn is somewhat unnerving.

What they said.... too rich. Dial the mixture screw back to 2.5 turns. Could be a mismatch between the needle/slide actuation. Bogs are usually too much fuel for the amount of air it's getting.

Yes...but also try pulling the snorkel out, and see what happens without any other changes...

Alexd

It's in the description of the video, but the snorkel is removed and it has a FMF slip on.

I haven't watched the video...and I missed that fact in your second post on this thread. But, as several have said, it seems to be rich. Verify that your float heights are within specs, then lower the main jet 1 notch.

I have a Z1 mod, not a FMF. But everything else the same as you (on three bikes, with same effect); at Sea Level I'm happy with a 127.50. So...130 for you maybe?

Alexd

It's fixed as far as I'm concerned.

I went up one on the pilot to 45, and replaced what I thought was a Mikuni 132.5 with a Mikuni 132.5 main jet.

The main jets that I ordered from RM ATV/MC were after market. The orifice in the orifice in the 132.5 EBC jet was actually smaller than the one in the stock 130.

I'm now at 2 turns on the pilot screw, and it's like a whole different bike. It'll bring the front wheel up in first and second, and has no hesitation when riding.