2001 CR250 Loading up while jumping?

[luckycharlie]

On the last 2 trips to the dunes my CR250 seems to be loading up, "bogging" once I land from a jump. If I rev it up while in the air, it will not always bog. While riding normally, the bike seems to be jetted good. Bike barely smokes once warm, kicks right aways, nice throttle responce, and idles fine.

I was thinking that the floats may be too high, but I was not too sure. The bike will sometimes drop a little fuel out the overflow tube when I pull it off the bike stand, but it does not run out like there is a stuck float.

I am running the Keihn pwk38 airstiker carb, and do not know the jetting. The carb was purchased and pre-jetted from Carb parts warehouse, and other than moving the needle down 1 position, I have not changed the jetting.

Has any one else experienced this "bogging" off of a jump problem, and found a solution? Any recomendations would be appreciated.

Thanks in advance.

[Wayward Son]

high float level.

[luckycharlie]

Thanks for the input, I will check them this week.

The Sudco website has the PWK's 38 with a float height at 16mm. Is this the desired height, or have others experimented and found different float settings that are prefered?

Any input will be appreciated.

[luckycharlie]

I pulled the carb last night, and reset the floats to 16mm. They were not off too far though.

I was surprised to see the amount of sand that was in the float bowl. This carb was brand new and has only been on the bike for 3 dune trips. The bike has an inline fuel filter that does on appear to have any sand in it. I am wondering if the sand is getting into the carb by the 4 Vent Hoses.

Has anyone else experienced this same problem with a Keihn PWK airstriker? Is there some method for routing the breather hoses so that sand/dirt can be eliminated/lessened? Right now the vent hoses run down the shock tunnel in the swingarm, and basically just hang there about 1 - 2 inches below the bottom of the swingarm.

I am now kinda assuming that the "Bog" could also have been coming from sand blocking the pilots jets? Although there was no sand blocking the pilot or main jets when I pulled and cleaned the carb.

Any information about improving the breather hose routing would be appreciated.

Thank you in advanced.

[Wayward Son]

the sand wasnt helping.thats for sure.

sand has ahabit of getting in everything.

[kuritaro9]

I pulled the carb last night, and reset the floats to 16mm. They were not off too far though.

I was surprised to see the amount of sand that was in the float bowl. This carb was brand new and has only been on the bike for 3 dune trips. The bike has an inline fuel filter that does on appear to have any sand in it. I am wondering if the sand is getting into the carb by the 4 Vent Hoses.

Has anyone else experienced this same problem with a Keihn PWK airstriker? Is there some method for routing the breather hoses so that sand/dirt can be eliminated/lessened? Right now the vent hoses run down the shock tunnel in the swingarm, and basically just hang there about 1 - 2 inches below the bottom of the swingarm.

I am now kinda assuming that the "Bog" could also have been coming from sand blocking the pilots jets? Although there was no sand blocking the pilot or main jets when I pulled and cleaned the carb.

Any information about improving the breather hose routing would be appreciated.

Thank you in advanced.

you could try to reroute the rear hoses to the side of the carb. that way, it wouldnt be getting hit directly from rear wheel or plowing into the sand on jump landings.

i have that same carb on my bike, but i have never found anything getting into the carb(although its mostly mud riding here)

you could also try the panty hose trick. i saw some of the race teams use this trick over here on some of the more sandy tracks. they took a hunk of panty hose, made a pouch out of them and stuffed the vent tubes in there and sungged it on with a zip ty.

[luckycharlie]

you could also try the panty hose trick. i saw some of the race teams use this trick over here on some of the more sandy tracks. they took a hunk of panty hose, made a pouch out of them and stuffed the vent tubes in there and sungged it on with a zip ty.

That is a great idea. I forgot that pantyhose were the Original Outerwears!

I will get that setup before my next dune trip.

[Wayward Son]

pretty good idea.

[rhinoracin]

You could also try this: http://7602racing.com/prod_t6cf.php

I have these carb filters on both my bikes and they work great