94 spx Carb Question

[jb2344]

Would the Low Speed needle valve being set too rich effect top-end performance?

 

[nswillin]

It could if it was fouling your plugs real bad

 

[jb2344]

I rebuilt the carbs and set the High speed at 0 and the Lowspeed at 1.5. I took it for a test run and it would never get on top and would bog. After reading posts, I realized that the 1.5 on the low speed was too rich and closed it down to 1. Immediately I had to idle the ski down quite a bit due to the increase of rpms from the correct mixture. I couldnt test run it tonight due to time, but I was just curious if this would cause the bogging.

 

[nswillin]

When you rebuilt your carbs did you set the pop off and do a leak test on the needle and seats? I don't have access to your manual right now but I'll look to make sure those carb adj are right.

 

[jb2344]

Pop-off was done. Mag was 25, pto was 23psi. The low speed jet is constantly spraying fuel right? Unlike the highspeed that only sprays when above 1/4 throttle?

 

[nswillin]

The low speed, at idle fuel is drawn up to the low speed jet. The low speed controls fuel flow for smooth idle and initial throttle response. High speed comes into play at about 3/8 throttle.

Specs on your deal is LS 1 1/4 +- 1/4
HS 0

Turning screw clockwise leans mixture and turning screw counterclockwise enriches mixture.

 

[timmyboy76]

accord'n to another source, specs call for. lsa=1-1/4, and hsa=3/8. ur pop-off is within specs, other than that, your main jet is 125, pilot is 60, and n/s(needle and seat) should be 2.0, with 22-29psi pop-off

 

[nswillin]

Don't really know your other source is but HS is 0 according to BRP on 1994 SPX.

 

[timmyboy76]

Spoke to, my fathers brother niece second cousin's fathers' aunts' sons' son, who build the ski....:rofl:

 

[nswillin]

I would stick to the manual. The high speed screw is sealed off with a plastic
cap that allows an adjustment of 1/4 turn. Do not take this cap off to adjust. Same as the LSS turning screw 1/4 turn counterclockwise enriches mixture and turning screw clockwise leans mixture.

 

[PWCdoc]

Yes, the low speed needle valve being too rich will effect your performance on top end due to the fact that the fuel circuitry is collective and not either or.