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otis
09-15-2007, 08:03 PM
Just brought home the 525xc. It has a small bog when you first hit the gas. If you push the throttle nice and slow it comes on fine. But when you give it full throttle from an idle it bogs. Also it wants to backfire when you let of the gas at high rpm's. For this I raised the clip 1 notch and it seems better but I only have one notch left. When it backfires when you let off the gas I think this is from to much gas and it burns off real quick. Is this correct. My elevation is 3900 ft. Any help would be appreciated.
Thanks

walty
09-16-2007, 06:29 AM
the pop on deceleration means it is LEAN ...to adjust use the screw at the bottom of the carb and unscrew it 1/4 turn at a time untill it does not pops any more

the needles have NOTHING to do with the pops

maybe a biggeg pilot jet can solve the pops but i dont think so!!!

the bog can normaly be solve with jetting (SEE yfz forum ,they use the same fcr carbs)

or it can be solve using a boysen quick shoot carb kit!!

patrickj75
09-16-2007, 07:11 AM
a bigger pilot will help. my 450R had that problem too.

MessinaRacePrep
09-16-2007, 04:32 PM
Ditto...

The FCR carbs have that problem at the bottom. They have a pump that squirts a shot of fuel (accel pump thingy) the fix is the Boysen thingy... LOL I forget the name...

patrickj75
09-16-2007, 04:36 PM
i put an 07 crf FCR on my 04 450r but didn't get the Boyeseen quickshot. i fixed the problem with the pilot jet. plus, they (Honda) fixed that problem with the new FCR carbs.

otis
09-16-2007, 08:15 PM
Which way did you go with your pilot jet? The adjusting screw on the bottom doesn't seem to have any effect at all.

patrickj75
09-16-2007, 08:19 PM
my setup with a pipe is 182 main, 50 pilot, 1 1/4 turns out on the screw, needle in the middle.

realbadlarry
09-16-2007, 09:48 PM
Go to KTM talk.com to get the fix for the ktm carbs. stay away from the quickshots. the general attitude of ktm owners is they don't work on these carbs. A honda AC pump diaphram and an oring on the linkage fix most of it. I put the HT racing vane in my 04 and fixed it. Lots of stuff to do to these, boysen is not one.

MessinaRacePrep
09-17-2007, 09:45 AM
Larry you are right abotu that I forgot abotu that fix.

bossman525
09-20-2007, 04:17 PM
my 525 outlaw was doing the same thing. i haven't changed pilot jet yet, but i raised the clip on the needle one position and it got rid of that off idle bog.

ktm450xc
11-03-2007, 05:09 AM
I WAS WONDERING WHAT SIZE OF PILOT AND MAIN JETS COME IN THE 450XC/525XC STOCK?

inthewoods10
11-03-2007, 09:02 AM
a 40 pilot in the 450 a 42 in the 525, a 45 will help on the bottom end, jd now has a kit for the ktm quad as of thursday this past week. Most ktm's do not have a leak jet which can be an issue on the bottom end, HMF has a slip on pipe out now , they had to reject went to a 45 pilot and down on the main needle to make is richer, but they also notice the ap squirts to long. JD jetting has great fixes if this seems to be a problem. I had ordered an R&D power bolw to replace the bottom end of the carb which has an ajustable leak jet in it, doing this for better dead engine starts for gncc racing.

realbadlarry
11-03-2007, 10:36 AM
Or just buy a honda pump diaphram. Go to KTM talk.com and look at the Hundreds of posts on this issue. Oring mod on the ac pump linkage, etc. Not that hard to figureout/fix.