ytm 225 carb tuning/jetting questions

[wide'n'low]

I've got a nice 84 dx225. When I bought it, it ran rough and didn't want to idle. Noticed the muffler is gutted out and rust patched everywhere, also i installed a New pleated paper style airfilter.

It came with a yfm250 carb kit, they had already used the needle valve.

so I cleaned the carb and it ran better but would pop when decelerating in 4-5 gears.
So i installed the rest of the kit. I noticed the main jets were very similar in sizing, however the pilots were quite different sizes, the new pilots side holes were half the size.

I took the AFR screw to full in, then out 1-1/2 turns. It ran well, idled good and started with some persuasion(had to choke it at 80-85°f, I went riding Sunday. The 1/8 mile trail to the sand had been turned into a Mud drag pit practically, tore through it where 450r's and 2wd utilities were getting stuck :) .it did good till it had been riden for a hour or so and while traversing the mug on the trail back to the parking lot it started to break up/bog a tad when riding its upper rpm band in second.

Got back and changed the jets back out, starts eaiser and seems to rev higher, i set the afr at 1-1/4 turns out. But now it pops on decel again....carb is clean and clear so are the jets, no float issues that I can tell.

Any ideas guys? something I'm missing? I have an extra

[Frankencelery]

Hmmm....popping on decel usually means you're too lean, and you can certainly go with a bigger main jet (or would that be the pilot jet in this case?), but I would guess your gutted muffler is the culprit. I had the same problem when I had a Cobra exhaust on my 225dx. Instead of rejetting the carb, I found a good stock muffler on Ebay and put that in. Solved my problem, and I don't care much for noisy machines anyway, so having it quiet is also a bonus.

[wide'n'low]

that's what i though, I tried richening the afr/changing the plug/running the larger of all the jets I have. no change
so I pulled the pleated style airfiter off and the popping is gone, back to a foamy I guess lol.

but it still does the thing as before, the real issue that I forgot to mention lol. where from idle throttle position, if you go wot it bogs out. doesn't do this if youre already above idle thought. and choke position doesn't change anything except the cold running afr stream like it should.

[DohcBikes]

Sounds like its a tad lean on the pilot. Also, have you tried raising the needle/lowering the clip?

The cause is your empty muffler, but if the noise doesn't bother you, it can probably be tuned to run better than it is currently running.

[wide'n'low]

Thats what I figured I'd try next is moving 1 position down on the needle. That is for the input guys, I've got a moose filer on now, still needs to be oiled though.