450 carb issues...i guess

[69zandar]

O.k. guys here is my issue. I have a 2007 trx450er and i just bought it a month ago. first real ride on some logging road with extended w.o.t. runs it would pop and miss. The exhaust was gray to whitish in the muffler so i assumed it was lean. When I got home and pulled the plug it showed signs of gray but was darker , i assumed it was due to more low speed driving back to the trailor, etc. It had a 162 main in it at this point so i installed a 165 ( it was the next size up I had ) . Next riding trip to the dunes here in washington and the w.o.t. seemed good, no problems. But I climbed a hill and it seemed like 3/4 throttle it was missing and popping again. I would say better than 1/2 to 3/4 throttle it misses and stumbles under a load, doesnt do it just cruising around at that throttle position. I was thinking I was a little lean in mid-range so I was going to raise the needle a clip position or so. Today I pulled the carb apart to do that (florence trip next week ) and the needle is raised as far as it can go, The clip is in the lowest position. unable to raise it anymore...Ha. Could it be too fat in the midrange? The needle is a ocgfp not sure if that is the correct needle since it is not the stock one. The quad has an aftermarket pipe Alba , quick shot 3 , stage 2 hot cam , and suppose to have a high compression piston . Anybody have any ideas ? Thanks a lot for the help, I have to get this fixed before my brother beats me with his 440ex in the dunes. Ha

[eastside 400]

no sure what your altitude is but try a 175 main, 42-45 pilot, needle mid way, 55 leak jet and fuel screw 2.5 out

[DnB_racing]

I know you said the plug and exhaust look lean, but the symptom of bogging or like a false rev limit under load sounds to rich..

im guessing its more then just one problem,

could be your needle or the air/fuel setting,

but from the symptoms it sound like 2 separate issues,
one being the main and the other being the needle or pilot circuit.

im guessing lean up top and rich in the middle

[69zandar]

Thanks Guys for the reply, I yanked the carb and decided to give it a complete once over. I found a 48 pilot, 162 main as I had said before , slow jet is a 75 (?) is that part of the quickshot 3 setup ? The carb seems all screwed up. Funny thing the a/f screw was only a half turn out which jives with the fat pilot jet. I am going with eastside 400 recommendation for a baseline and go from there. I am excited to get this dialed in !! Thanks for the help !! One last question......Is anyone familiar with the quickshot 3 set up ? Do you fatten up the shot by turning it counter clockwise or visa versa ? It is 3 turns out from bottomed out.

[ewalker302]

looks like you have an 07, and eastside, an 05.

04-05 has a different carb than 06+......04-05 runs bigger main jet.

[69zandar]

Oh, well i am going to do a test and tune today. The main is the easiest of the bunch so we shall see what I end up with. :)

[eastside 400]

i have a FCR carb on mine. i understand the differences

[69zandar]

"i have a FCR carb on mine. i understand the differences"

Thanks eastside ! I agree that you did, my quad runs 100% better . I didnt have to touch a thing and it ran great at the dunes ( smoked a yfz and an ltr 450 ! ) That always makes you feel good !!