[speedtrip]

Are you guys removing the backfire screen in front of the air filter? I removed the snorkel from the airbox and would love to screen off the hole to keep some of the big junk out and put the screen to good use.

Does anyone know if I should be using the

16012-kpt-921 or
16012-kps-921 needle?

Thanks in advance
BTW It is a 06 crf150f

[livinglarge]

From what I saw when going through this on my sons '06 150F, the KPT is 150 andthe KPS is the 230. I ordered the KPS by mistake and returned it before opening the pack and got the KPT. It fits great. Dropped in the 110/42 combo, new needle in 4th grove from top, didn't touch the fuel screw and it seems to run great. Can't ride it yet with the snow but so far, huge improvement in cold starting, idle, quick roll on, etc. I'm going to leave the screen as is and keep the airbox top open. I think it will be fine and the screen is a good backup in case.

[speedtrip]

Thanks LL.

Have done the same to the jetting myself. Ordered a Twinair air filter with the laminated backfire screen, so I went ahead and pulled it out. There is about four layers of mesh in there, one just sitting there loosely folded in half between the 2 layers. Good tip for the needles too. I just finished my sons ttr 225 with richer pilot and good air filter, the difference in cold starting and warm-up is huge.

We have crappy weather in Oregon too at the time. Spring is just around the corner!!

[livinglarge]

So Twinair's have a built in back fire screen? Please explain more. I put a Uni in my sons 150F and just left the screen in place. I assume there is just the one layrer of screen in the air box but you're saying there are more layers than what can be seen when removing the air filter?

[speedtrip]

I was going to upgrade the air filter no matter what. Liked the look of the Twin-air since they have that rubber grommet in the middle. Have torn a Uni spinning the napalm nut out. (I do not think this is a concern in the CRF 150 due to the mounting design in the airbox)
Anyways, after looking at a catalog the description said that all F-stroke models come with a laminated backfire screen. So I decided to pull the brass one out of the CRF.
Made a little cut with a blade into it and grabbed it with a pair of pliers to rip it out, well I was just doing the first layer. There is another piece of screening folded in half behind the one that you can see and another layer behind that one that is glued in too. I put them all together and blew some air through it. The velocity was pretty weak through all those layers!
Hope this helps. I guess if you were real careful you could just remove one layer of screen and the folded one.