I actually think it´s 60 slow on ducs...come to think of it....steve speed wrote:thanks killer ,,,,i have some 48 slow jets on the way and with the bigger main jets we should be sorted![]()
fcr main jets
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- Killerwhale
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Re: fcr main jets
- steve speed
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Re: fcr main jets
just a thought is the fuel pump up to the job of the demands of the new carbs ,,,,,anyone ?????
TRX850 ,The thinking mans R1
- Killerwhale
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Re: fcr main jets
yessteve speed wrote:just a thought is the fuel pump up to the job of the demands of the new carbs ,,,,,anyone ?????
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Re: fcr main jets
fitted 160 main jets ,, and allthough better its still a tad lean !!! 165s on there way in
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cobbadiggabuddyblooo
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Re: fcr main jets
ALBATROSS!!!!
Thanks for the insight fella's. Got a stocky trx,fitted with staintunes and just picked up a new set of fcr..41's and waiting on delivery.. Will opt for foam airpodsand big bore system eventually instead of airbox fitted with k&n filter and std headers at present...(budget...dammm just wrote off the missses car $3500...yesterday.. ouch) Will be interested to see whats fitted(jetting wise) when they arrive.
Dont know wheather it would be worth ginning around with carb's until big bore headers are fitted tho . So got a ballpark for jetting with std headers (s/tunes) and airbox (K&N) to start???? or is that usually factory setting as such from Kehien...
AAAH the plott thickens.. Anyone got some demensions for a big bore system(to get some manufactured myself)
..2 into 1 into 2 or 2 into 1.. Have heard about the flow restrictions from std headers (first bend out of head)even moreso with larger carbs when fitted (defeating the purpose really, like shitting through a straw when you think bout it)
Though akropovic 2 into 1 have taken my eye.
Any input would be greatly appreciated... Thanks again...CWOOTHERFICTION...Bwian
Thanks for the insight fella's. Got a stocky trx,fitted with staintunes and just picked up a new set of fcr..41's and waiting on delivery.. Will opt for foam airpodsand big bore system eventually instead of airbox fitted with k&n filter and std headers at present...(budget...dammm just wrote off the missses car $3500...yesterday.. ouch) Will be interested to see whats fitted(jetting wise) when they arrive.
Dont know wheather it would be worth ginning around with carb's until big bore headers are fitted tho . So got a ballpark for jetting with std headers (s/tunes) and airbox (K&N) to start???? or is that usually factory setting as such from Kehien...
AAAH the plott thickens.. Anyone got some demensions for a big bore system(to get some manufactured myself)
Though akropovic 2 into 1 have taken my eye.
laughter is the best medicine
- Killerwhale
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Re: fcr main jets
As said mate, i´ve done all that and ended up with 170 in the Swedish climate.steve speed wrote:fitted 160 main jets ,, and allthough better its still a tad lean !!! 165s on there way in
Can also add, i´ve found a small sketch of how Max was jetting and No1 was bigger than No2....
- steve speed
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Re: fcr main jets
no i think it was No 2 that had the bigger main jet , i think it was 165 ,,, with the left pot No1 at 160
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cobbadiggabuddyblooo
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Re: fcr main jets
yes no.2 makes sense as being a 270 degree crank , no 1 would be firing 90 degrees after no.2 being 270deg then 90deg on no.1 to start the rotation at 0 once more then another 270 bla bla bla..and I'm sure you would want the first(being no2) cylinder being the richer and the 2nd cylinder(no 1) the leaner which is how i've set up the std carbs at present after dyno runs.
Noticed on site a fellow in sydney who wants to exchange a hi flow 2 into 1 system for a set of cans so may ultimately be able to do it for maximum benifit to start. do it right the first time as such.
cheers Bwian

Noticed on site a fellow in sydney who wants to exchange a hi flow 2 into 1 system for a set of cans so may ultimately be able to do it for maximum benifit to start. do it right the first time as such.
cheers Bwian
laughter is the best medicine
- steve speed
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Re: fcr main jets
i think max thought it was something to do with No2 being more insulated because of the cam chain tunnel so it ran a bit hotter
these are my settings , they maybe a bit rich but only the dyno can tell me now but it feels right with no holes in the power and from a standstill it takes off well, but i do need to warm it up as it runs a bit rough for 2 mins (no choke ? )fcr41mm
main jets 165
needle clip 5th from top
slow jet 48
main air jet 200
fuel screw 1.5 turns out
slow screw .75 turns out
ram air pod filters
and all the popping and banging has gone on the overrun
these are my settings , they maybe a bit rich but only the dyno can tell me now but it feels right with no holes in the power and from a standstill it takes off well, but i do need to warm it up as it runs a bit rough for 2 mins (no choke ? )fcr41mm
main jets 165
needle clip 5th from top
slow jet 48
main air jet 200
fuel screw 1.5 turns out
slow screw .75 turns out
ram air pod filters
and all the popping and banging has gone on the overrun
TRX850 ,The thinking mans R1
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cobbadiggabuddyblooo
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Re: fcr main jets
Package arrived today with carbs and factory set at 150 mains,looks like I may have an exchange big bore exhaust for my staintunes so only chasing foam filters now. The 170 mains in yours steve,is that with big bore exhaust aswell as ramair foam filters???
laughter is the best medicine
- steve speed
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Re: fcr main jets
i haven't got 170scobbadiggabuddyblooo wrote:Package arrived today with carbs and factory set at 150 mains,looks like I may have an exchange big bore exhaust for my staintunes so only chasing foam filters now. The 170 mains in yours steve,is that with big bore exhaust as well as ram air foam filters???
mine are 165
and yes i have ram air filters and big bore downpipes
anyway i went on the dyno today at quill exhaust and i have just about got it spot on,
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Re: fcr main jets
On my first dyno before 878cc it puffs out a deciliter of oil or something, think the video is still out there!steve speed wrote:i haven't got 170scobbadiggabuddyblooo wrote:Package arrived today with carbs and factory set at 150 mains,looks like I may have an exchange big bore exhaust for my staintunes so only chasing foam filters now. The 170 mains in yours steve,is that with big bore exhaust as well as ram air foam filters???
mine are 165
and yes i have ram air filters and big bore downpipes
anyway i went on the dyno today at quill exhaust and i have just about got it spot on,its still a bit lean on the needle so i will lift it 1 clip , so that will be 6th from the top , i only got 85bhp but the dyno man said there's reads low ,, so not to bad it was amazing to see all the smoke coming from the exhausts on the over run you never see it on the road , hopefully i can sort that when i rebuild the engine soon , it does use 1lt of oil every 1000 miles , but even as it is it feels like its got twice as much power as it did std
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Did you film it??
- steve speed
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Re: fcr main jets
no i didnt film it as i only called in on the off chance of a run,, the guys there are very good very helpfull,, you always get a coffee,and a load of help 
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Re: fcr main jets
You got a LOAD????steve speed wrote:no i didnt film it as i only called in on the off chance of a run,, the guys there are very good very helpfull,, you always get a coffee,and a load of help
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