running rich ? ;s

[kwackkev22]

can anyone tell me if theres a fool proof way of telling if your bikes running rich mines spluttering around 5000rpm and under load and it reminds me of a rm250 i had it would never hit the power band and splutter so i went out on it one day and took a small screw driver with me and alterd the mixture screw a bit at a time and got it running mint
its not that easy on the zxr tho as theres 4 carbs to deal with. heres whats wrong with the bike
1)plugs 1 and 3 on my bike are matt black and 2 and 4 are ok is it possable to run rich on the odd cillinder ? (brand new plugs )
2)the exhaust tip gets matt black after a very short ride
3)the revs hang and take a bit to drop
4) the bike bogs when you pull the throttle back sharp

would the bike have to be set up on a rolling road ive found a local bloke that wants £50 an hour and £30 a run on hes rolling road and hes only doing it as a hobby now
thnks for any help i think the above is good grounds for running rich

[RedexRobB]

has it always been like that kev?

Bogging when you open the throttle is a sign of running rich, but with the revs hanging it could also be a leak sucking air. On these bikes typically the inlet rubber so maybe a new set is required. The mixture screws only adjust for lower revs upto when the main jets come in iirc, its the main jets you may need to alter. Its quite normal for the tip to get black, im most most people here have the tips of thier exhaust black. If they didnt go black we wouldnt be worrying about Co2 emissions.

If you want to get it spot on i think a colourtune kit will do it nicely, and yes it is possible to run rich on the odd cylinder. My bike has staggered jets 88, 90,90,88 i think they are, but the plugs are pretty much the same colour. Rolling road should get it perfect, they could probably tell you why its spluttering at 5k as they can sometimes monitor the air/fuel as the bike runs.

I suspect its your inlet rubbers at the moment tho, if you have some carb cleaner, start the bike and spray it round the inlets and if the engine runs differently, then they probably need changing.

[kwackkev22]

yeah its allways boged out sorry to have this problem plasterd all over the site i checked the inlet rubbers one did look to have some sign of hair line cracks but they didnt come all the way through the rubber i cleaned and checked them over this weekend theres only one that had the hair line cracks each one had a coat of instant gasket just to help seal them up better and i tried the carb cleaner on the inlets with it running and it didnt do anything so iam guessing there ok ive found a good dyno place in nottingham so iam gonner drop them an email see what they say
thanks

[MillaMeter]

can anyone tell me if theres a fool proof way of telling if your bikes running rich mines spluttering around 5000rpm and under load and it reminds me of a rm250 i had it would never hit the power band and splutter so i went out on it one day and took a small screw driver with me and alterd the mixture screw a bit at a time and got it running mint
its not that easy on the zxr tho as theres 4 carbs to deal with. heres whats wrong with the bike
1)plugs 1 and 3 on my bike are matt black and 2 and 4 are ok is it possable to run rich on the odd cillinder ? (brand new plugs )
2)the exhaust tip gets matt black after a very short ride
3)the revs hang and take a bit to drop
4) the bike bogs when you pull the throttle back sharp

would the bike have to be set up on a rolling road ive found a local bloke that wants £50 an hour and £30 a run on hes rolling road and hes only doing it as a hobby now
thnks for any help i think the above is good grounds for running rich

Hi,

Sup Kev, I got exactly the same problem, check this thread!viewtopic.php?f=7&t=8789
I have also bought new inlet manifolds and sealed them with silicone sealer, sprayed them with carb cleaner to check if they're leaking and nothing. the idle has it's moments sometimes. I think it may be valve clearences messing the mixture up?

Regards

Rich