jets

[garystaff]

hi all what is the size of the main jet on rd 250 is it 110 because I've just put set on micron pipes on and at full throttle it bogs down just wounded if it needed up jetting thanks  

[muttsnuts]

which model, C,D, E or F ?

[garystaff]

Mar 17, 2015 20:51:19 GMT 1 muttsnuts said:

which model, C,D, E or F ?

is 79 f

[muttsnuts]

um, sound a bit small to me, I need to check, but think 120's or 125's might be nearer the mark, needle needs to start in the mid positon (3rd clip), have you tried moving the needle to see if it makes a difference, also have you done a plug chop at all ?

You running the standard airbox and snorkel, or snorkel removed etc ?

[garystaff]

Mar 17, 2015 21:09:52 GMT 1 muttsnuts said:

um, sound a bit small to me, I need to check, but think 120's or 125's might be nearer the mark, needle needs to start in the mid positon (3rd clip), have you tried moving the needle to see if it makes a difference, also have you done a plug chop at all ?

You running the standard airbox and snorkel, or snorkel removed etc ?

standard air box noise not done nothing to it yet just needed to find size of standed jet so i could order some bigger jets so the standed jet are 120 or 125 or is that what i should put it thanks

[muttsnuts]

hang on letme check and I'll tell you for sure

[muttsnuts]

right ok, standard main jet is 115

I tend to fit 120's for a standard build these days and drop the needle down to compensate, the reason I up jet is becuase the quality of today's fuel isn't great and the ethanol in it makes the engines run a tad leaner

if you remove the snorkel (gives you a few ponies for nothing) then I go to 125's and again adjust the needle to compensate, the exact settings for your bike will vary, and ideally you want it checking/setting up on a dyno with an air/fuel ratio tester.

I'd start with 120 and the needle in the middle, if it runs a tad "fluffy" at the top end, then drop the needle one notch, so that means moving the clip "upwards" to position 2 from 3, this lowers the needle into the main jet so that it runs leaner at higher RPM

HTH

[garystaff]

[garystaff]

Mar 17, 2015 21:37:48 GMT 1 muttsnuts said:

right ok, standard main jet is 115

I tend to fit 120's for a standard build these days and drop the needle down to compensate, the reason I up jet is becuase the quality of today's fuel isn't great and the ethanol in it makes the engines run a tad leaner

if you remove the snorkel (gives you a few ponies for nothing) then I go to 125's and again adjust the needle to compensate, the exact settings for your bike will vary, and ideally you want it checking/setting up on a dyno with an air/fuel ratio tester.

I'd start with 120 and the needle in the middle, if it runs a tad "fluffy" at the top end, then drop the needle one notch, so that means moving the clip "upwards" to position 2 from 3, this lowers the needle into the main jet so that it runs leaner at higher RPM

HTH

cheers thanks for all your help I've order 120 125 jet so when i get them are try that thanks 

[garystaff]

hi all thinking of putting 350 barral  on my rd 250 what would i have to change thanks

[lance]

Leave it alone ran well when you lent me it mate