strong down low but it doesn't fell strong up top...jetting

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royster81
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strong down low but it doesn't fell strong up top...jetting

Post by royster81 »

here guys ,just back from a run with the wife on our road nc's and i have a funny feeling going on
i feel the bike pulls really well from low down but once the revs get up the top of the range it kinda feels like it's running outta puff

the bike has a twin stack
115/118 jets
FI needles on the 2 clip
0.5mm washers all round
a cut filter with the one layer of HRC foam

low down like i say it's class but up top ....i just feel it doesn't pull so strong,could the jetting but really off?
It's not having what you want but wanting what you've got....Loud ,Proud and Modified ....
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viper_biker
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Re: strong down low but it doesn't fell strong up top...jetting

Post by viper_biker »

Any spare jets lying about in the garage? I'll have a look and see what I have, but I think all I have are standard RVF ones and 122's and 124's in the VFR spare carbs.
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royster81
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Re: strong down low but it doesn't fell strong up top...jetting

Post by royster81 »

well i took 120's out from all round as it was fire flames on the over run,to be honest it pulls better with the smaller ones but if the answer to getting the top end back in putting in the 120's i'll go again and put them back in
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viper_biker
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Re: strong down low but it doesn't fell strong up top...jetting

Post by viper_biker »

What about 118f and 120r then instead of 20's all round?
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CMSMJ1
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Re: strong down low but it doesn't fell strong up top...jetting

Post by CMSMJ1 »

viper_biker wrote:What about 118f and 120r then instead of 20's all round?
Bingo :mrgreen:
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The V4 is the law..

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royster81
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Re: strong down low but it doesn't fell strong up top...jetting

Post by royster81 »

but i remember reading on here that honda jets and dyno-jet jets are a little different in there sizing an not always uniform like you'd want it

i changed the FI needles the same time i down jetted ( yeah i know :roll: ) so can say if it's the needles are the jets making the difference,i'll take the carbs out ( again) to put back in the flame throwers and see how that goes.....


is it just me or would anybody else like PGM FI ?
It's not having what you want but wanting what you've got....Loud ,Proud and Modified ....
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royster81
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Re: strong down low but it doesn't fell strong up top...jetting

Post by royster81 »

back to the flame throwers then...

i'll report back to tell you how this has gone (if anyone was interested)
It's not having what you want but wanting what you've got....Loud ,Proud and Modified ....
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two_smoke
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Re: strong down low but it doesn't fell strong up top...jetting

Post by two_smoke »

I'm interested :) Having similar problems :x
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Re: strong down low but it doesn't fell strong up top...jetting

Post by CRM »

hello paul, still hanging in there with the NC then ? hope you are well, long time no speak
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RVF
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Re: strong down low but it doesn't fell strong up top...jetting

Post by RVF »

Dynojet jets tend to be richer than keihins. This is more to do with jet lenth rather than hole dia though. I would stick with Keihin jets where ever possible.

PGM-FI you say, you want one of these :D

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