needle replacement

[Thomas/Sparks]

When you change the size of the needle in the carb do you have to change the seat also? I was told you had to.

 

[motochick]

A long time ago they used to call the float valve, a "needle and seat". It is down in the float bowl and I have only replaced mine when it wears out.

If you are talking about replacing the needle jet, the long skinning thing with the notches in it that goes in the slide, then no, there would be no "seat" to change.

Hope this helps,
Brenda

 

[Thomas/Sparks]

Yea, the needle jet is what I'm talking about.I went to a one step leaner than the stock needle jet and I could not get the bike to start unless I pulled it.I put the old one back in and it starts just fine.

 

[Canadian Dave]

What did you remove and what did you install? What position was the clip in? Normally if the bike won't start its because its not getting enough gas when the engine is cold. Though this could certainly be effected by your choice of jet needles its often associated with a lean pilot circuit. It could be you pilot circuit is too lean but your original needle was rich enough to compensate?

David

 

[Thomas/Sparks]

I'm lost when it comes to jetting so bear with me.I removed a 68 needle and put in a 67, the main is 65 and the lean poilot is 42. I also took 1mm off the slide. I did this trying to get a better bottom end response and get rid of the spooge. When I put the 67 needle in it seemed to have less spooge,but would not crank.When I put the 68 needle in it cranks o.k. but has alot of spooge. Where do I go from here???? I did check my compression and with the throttle wide open and 5 kicks it went to 150lbs. I need alot of help!!!!!!

 

[spanky250]

Thomas, put the 67 needle in the third clip position, and go to a 45 pilot. That should cure your starting problems. I only run a 42 pilot in the high heat of summer, I go to a 45 when it is cool outside.

Also, 150 psi is low for the compression, my engine has around 190 when it is fresh.

 

[Thomas/Sparks]

I will give it a try and will let you know how it works out.Another question is I use Motul 800 oil.My bike smokes alot ,is this because of the type of oil, wrong jetting,or worn rings?