Pulling A Jet


7 replies to this topic
  • AlkalineOne

Posted February 01, 2007 - 09:50 PM

#1

ok, im trying to do this without taking apart the whole bottom end of the carb. im trying to pull the pilot jet out, but is extremely tight, and the thing is almost striped out. should i keep trying and get it to budge, or remove the fload bowl to fit a larger screw driver in?

thanks

  • rexbond007

Posted February 01, 2007 - 10:25 PM

#2

I took my float bowl cover off to pull my pilot, while the carb was installed on the bike, it was a bugger. then i realized i didn't have to. but to be on the safe side, not to strip the jet. do it.

  • AlkalineOne

Posted February 01, 2007 - 10:26 PM

#3

ok nevermind, i got it, but i have to share... i just replaced my stock pilot #42 with the #45, and for the first time it turned over on the first kick with no choke(cold)... i guess all you guys were right. thanks!

  • Idaho_Stas

Posted February 01, 2007 - 11:00 PM

#4

ok nevermind, i got it, but i have to share... i just replaced my stock pilot #42 with the #45, and for the first time it turned over on the first kick with no choke(cold)... i guess all you guys were right. thanks!


Depending on how cold your talking, and what your altitude is, you may even need to go to a #48. I use a #48 in the winter, and drop to the #45 in the summer. Still wondering what Yami was thinking shipping those things out of the factory w/ a #42 in em.

Also... if you don't already have one, go get a fuel mixture screw so you can get that thing dialed in.:ride:

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  • AlkalineOne

Posted February 01, 2007 - 11:20 PM

#5

Depending on how cold your talking, and what your altitude is, you may even need to go to a #48. I use a #48 in the winter, and drop to the #45 in the summer. Still wondering what Yami was thinking shipping those things out of the factory w/ a #42 in em.

Also... if you don't already have one, go get a fuel mixture screw so you can get that thing dialed in.:ride:


thanks, the first thing i went with was the fuel mixture screw which helped the starting/popping problem dramaticaly, but i knew i had to change the pilot so i finally got around to it. i ride between 2,000 and 4,000 ft. so i think the #45 will work great. plus im in so. cal., so its not too cold. i've heard that stalling is an issue with the #48, so i'll deal with a few pops here or there to avoid the stall.

+ im about 200 ft above sea and about 55 degrees out, when i just started it up for the test.:ride:

  • rob fowler

Posted February 02, 2007 - 06:48 AM

#6

Just my opinion on the lean jetting for the yamaha yz 450. They are ok @100degree temp with dry conditions low humidity. They can not jet these bikes for all geographic areas. Also, do to the fact that they are getting the maximum horsepower from the engine and running on the edge for performance they do not want you to break them in @ maximum performance for reliabilty reasons. To rich and the rings will not seat properly and the wear will be excessive due to wash down of the cylinder walls. Therefore, after break in you should address any jetting issues according to elevation , temperature , and humidity.06 yz 450@640 above sea level I am running stock main with 48 pilot, and adjustable fuel screw. No issues bike runs perfect everthing else totally stock...In the motocross world this is just something you have to do.

  • Idaho_Stas

Posted February 02, 2007 - 07:54 AM

#7

Just my opinion on the lean jetting for the yamaha yz 450. They are ok @100degree temp with dry conditions low humidity. They can not jet these bikes for all geographic areas. Also, do to the fact that they are getting the maximum horsepower from the engine and running on the edge for performance they do not want you to break them in @ maximum performance for reliabilty reasons. To rich and the rings will not seat properly and the wear will be excessive due to wash down of the cylinder walls. Therefore, after break in you should address any jetting issues according to elevation , temperature , and humidity.06 yz 450@640 above sea level I am running stock main with 48 pilot, and adjustable fuel screw. No issues bike runs perfect everthing else totally stock...In the motocross world this is just something you have to do.


I agree with you as far as Yamaha is concerned... but they should work with their dealer network and the techs that set these bikes up (who do know the elevation and temp. extremes for their areas) to change the jetting to match the altitude/temps of the local riding areas and to instruct the 'newbie' owners that if they want to ride in the winter as the temps drop, they'll need to richen things up a bit. (or get used to a lot of popping, backfiring and dead spots).

I ride snowmobiles as well as bikes, and none of the local sled dealers would even think about selling a sled without adjusting the jetting to the local riding areas (granted, snowmobiles are much more likely to go through extreme altitude changes where jetting becomes crucial). Why should bikes be any different?

  • AlkalineOne

Posted February 02, 2007 - 05:43 PM

#8

I agree with you as far as Yamaha is concerned... but they should work with their dealer network and the techs that set these bikes up (who do know the elevation and temp. extremes for their areas) to change the jetting to match the altitude/temps of the local riding areas and to instruct the 'newbie' owners that if they want to ride in the winter as the temps drop, they'll need to richen things up a bit. (or get used to a lot of popping, backfiring and dead spots).

I ride snowmobiles as well as bikes, and none of the local sled dealers would even think about selling a sled without adjusting the jetting to the local riding areas (granted, snowmobiles are much more likely to go through extreme altitude changes where jetting becomes crucial). Why should bikes be any different?


my word... well put :ride:





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