Pilot jets

[penman]

Hi all,

I would be interested to know what size pilot jets people recommend. I've tried 50, 44 and 42, those being the sizes I have to hand. 42 is definitely the best for me, but I suspect I could go smaller still. The problem is that the progression orifice mixture is only controlled by the size of the jet and I find that with the standard 50 jet, it tends to hesitate coming off idle - presumably due to the difference in modern fuel. You can improve it a bit by making the idle mixture leaner, but that's at the expense of reliable idling, especially when not fully warm. Moving to a 44 jet seems to be quite a big improvement and 42 is better again for me. Even going from 50 to 42 only needs a small adjustment of idling mixture.

Anyone else been down this route?

Regards,

Joe.

[72degrees]

I'm running 45s - but that's on PHBH28s.

[EVguru]

Time for a larger slide cutaway as an alternative way of leaning out progression.

No amount of playing with the idle jet would sort my 125H out, but going from a 40 slide to a 50 did the job.

[penman]

Time for a larger slide cutaway as an alternative way of leaning out progression.

No amount of playing with the idle jet would sort my 125H out, but going from a 40 slide to a 50 did the job.

Thanks Paul, that does make sense. The only slide now stocked by Eurocarb is 60, which may be OK but at £45+VAT+post EACH, it's not a cheap option. I could easily modify the existing 50 slides, but that's a one-way trip. So, I guess I'll have to explore the possibilities of fiddling about with pilot jet and atomiser first. 42 pilot is pretty close, I may decide to live with the small hesitation.

[72degrees]

Time for a larger slide cutaway as an alternative way of leaning out progression.

No amount of playing with the idle jet would sort my 125H out, but going from a 40 slide to a 50 did the job.

Thanks Paul, that does make sense. The only slide now stocked by Eurocarb is 60, which may be OK but at £45+VAT+post EACH, it's not a cheap option. I could easily modify the existing 50 slides, but that's a one-way trip. So, I guess I'll have to explore the possibilities of fiddling about with pilot jet and atomiser first. 42 pilot is pretty close, I may decide to live with the small hesitation.

No shortage of VHB 7147.50 slides in my shed. Give me a shout and I'll post a couple.