Carburetor Adjustment : Yamaha R1 Forum

BrenR1 · 08-16-2005, 05:10 PM

Hey guys, i bought myself a 2000 R1 about 1month ago. Payed $8000, the guy i bought it off wasn interested in making big bucks from it. The previous owner to him owned the bike since new & spent $5500 on mods in 2002 on th bike, including full race tech suspension, steering damper, full Pipemaster Exhuast & a few other things including chain and sprockets, K&N Filter. Bike has 17500Ks.

However the bike has a problem bellow 3000revs. Taking off from lights anywhere bellow 3000revs the bike just stutters like crazy, im not sure what the best way is to explain it but it just doesn hav any power bellow 3000rpm. I can take off smoothly bellow 3k if being gentle and im not trying to take of quick. As soon as its over 3k it takes off with no problems, very fast. Same goes for riding along in any gear doesn matter wat speed im doing if i try to give the bike some juice bellow 3k it just doesn respond properly. I was aware of the problem when i bought the bike as the owner explained it, he told me it was because the bike hasn been tuned with the exhuast properly or something? Im just curious if this is likely to be the case & is there any chance i could improve the problem myself by adjusting the mixture screw on the carby? I guess eventually i will have it done professionally but for now im paying the bike off

Also th bike came with a Dyno readout. It has printed on the sheet, WinPEP, Dynojet performance evaluation program.
DynoRUN.003 Full Pipmastro 10/2/02. Its says power=134.2 & MPH=14.58 does this mean th speedo is out 14.58ks at all an im curious wat do these bikes have standard approx?

Cheers guys.

martinc · 08-17-2005, 03:48 AM

Yes,you can try adjusting the mixture screws,but that could also be the caracter of the full race pipe;but what I"d do is the easy thing;raise your idle to 1450~1500 rpms and enjoy!

BrenR1 · 08-17-2005, 04:05 AM

Thank's for that martinc. Ill have to give it ago in th morning.

PyRo1509 · 08-17-2005, 04:08 AM

since the exup is gone... its gonna act like that.
I have the same problem even with the exup stil on... but i assume it would b alot worse without it..
3000+ is where i cant start bouncing it... under that its like.... riding a lawnmower... putt putt putt

BrenR1 · 08-18-2005, 04:17 PM

Surely it could be fixed on a dyno tho, are you saying that because of the exup being gone the bike will do this with no way of fixing it?

martinc · 08-19-2005, 03:36 AM

There is a way,its called a Flo-Commander (installed on the pilot jets circuit)....but raising the idle is mucho less costly!

BrenR1 · 08-20-2005, 04:42 PM

Would a Flo-commander eliminate the problem all together.

I raised th idle to 1500rpm however the problem is still there, i tried raising the idle alittle more which improved the issue but i had to take it back to 1500 because its annoying when u sit at the lights etc. Im just curious, if anyone will explain this for me, whats happening to the engine when you remove its exup system? i understand the exup is a valve designed to increase/decrease backpressure at lower engine speeds but if you then take it away does that mean it doesn get enough backpressure at low revs.

martinc · 08-20-2005, 05:01 PM

Exactly,not enough back pressure.

The whole head design relies on the exup at low revs.

Yes,a flo-commander on the pilot jets circuit will allow you to fine tune it till you"re satified.