fcr main jets

[steve speed]

just spoke to steve @ allen's and he suggests i give 160 maybe 165 main jets a go so they are on the way , from how i described it he to thought it was a bit lean ,,,so if i have a bigger main jet do i drop the needle a bit ,,i suppose the only way to be sure is stick it the dyno ,, can they all tell if the mixture is correct ?

[Killerwhale]

just spoke to steve @ allen's and he suggests i give 160 maybe 165 main jets a go so they are on the way , from how i described it he to thought it was a bit lean ,,,so if i have a bigger main jet do i drop the needle a bit ,,i suppose the only way to be sure is stick it the dyno ,, can they all tell if the mixture is correct ?

I don´t know of a dyno in Sweden without A/F anyway...
If you have a 2-1-2 system any can would do for measurement but if you have 2-2 you should measure on the one cylinder wich runs leaner.
From memory number one but don´t take that for granted as i always forgets wich it is.

A search in here will tell wich cylinder MAX has jetted bigger.....

[steve speed]

i have allready spoke to max and he said the right one runs a bit hotter he also did use 160 and 165 ,,,now what do i do with the needle up or down ?

[Killerwhale]

i have allready spoke to max and he said the right one runs a bit hotter he also did use 160 and 165 ,,,now what do i do with the needle up or down ?

Measure it, don´t guess!
....i´ve as said raised the clip 2 grooves but think it´s a tad to lean now.
Make it one clip and see what dyno says?

[HansJ]

i have allready spoke to max and he said the right one runs a bit hotter he also did use 160 and 165 ,,,now what do i do with the needle up or down ?

I'd keep it like it was. Needle positione determines half open throttle, mains full. Of course middle range will be affected by change of mains, but it might need it as well. It's easy enough to play around with needle positions afterwards (in comparison with changing mains, at least on the Mikunis...)

[steve speed]

i just need to find a dyno near me thats got somone who knows what there doing ,,,v&m used to be about 2 miles away but i think they have shut shop

[Killerwhale]

i have allready spoke to max and he said the right one runs a bit hotter he also did use 160 and 165 ,,,now what do i do with the needle up or down ?

I'd keep it like it was. Needle positione determines half open throttle, mains full. Of course middle range will be affected by change of mains, but it might need it as well. It's easy enough to play around with needle positions afterwards (in comparison with changing mains, at least on the Mikunis...)

Other way around on the kehins according to me, and as far as i know the Kehin´s are more prone to need change on the needle when changing main than the mik´s are (according to factory pro anyway)

[steve speed]

so lower the needle pehaps one slot down with the 160s in

[steve speed]

well i just had a chat with steve mellor ,,hes one half of v&m racing and he is running a Yamaha race team now but his dyno is off-limits now to punters,,so i had a trawl round locally and found one £35 a go ,,so i hope i don't need to many goes

[Killerwhale]

well i just had a chat with steve mellor ,,hes one half of v&m racing and he is running a Yamaha race team now but his dyno is off-limits now to punters,,so i had a trawl round locally and found one £35 a go ,,so i hope i don't need to many goes

If they are experienced i can´t imagine more than two actually, maybe you can lend tools on site and change jetting yourself and hop on the same day...!?

[cheesie]

leave needle pos as is if it is in the third pos from top, stick the 160 mains in take it for a blast if better then try the 165 if worse you have gone to far, get yourself a set of 158s for fine tunning if the 160 mains work best dont worry about the dyno for now you will feel a difference on the road once your happy then take it to a dyno the needle afects 1/4 to 3/4 throttle the mains 3/4 to wot needle pos diameter and taper has the biggest effect in the range. enjoy fochterin

[steve speed]

this is whats in the carbs now

main jet 155
needle clip 3rd from top
60 slow jet
float valve 2mm
fuel screw 1/2 a turn out
main air jet 200
float is set to 9mm
1.5 turn on the slow air

i think the slow jets a bit big as it should be 48 which is probably why the fuel screw is only 1/2 a turn out it should be 1 turn out ,, needle is also a bit lean,, but as above i will leave it as is
it is hunting a bit at constant half throttle any ideas ???

[Killerwhale]

These are the standard for TRX from factory:

150 Main Jet
48 Slow Jet
200 Main Air Jet
OC EMP/4 Jet needle
1,0 Fuel screw
1,5 Slow Air screw

[Kayla]

If you think it's a bit lean at half throttle you could try raising the needle a notch (or half a notch using a small washer), but things might change with larger mains in.

[steve speed]

thanks killer ,,,,i have some 48 slow jets on the way and with the bigger main jets we should be sorted