Problem with my 99 900rr
#1
Problem with my 99 900rr
hey peoples, i need some info here. im having issues with my 99 900RR, the problem is that my spark plugs are getting BLACK, and these are new from a dealership, i have an Keihin FCR39 carburator on it and i wanted to know why this is happening??? and how can i fix it.
#3
#5
RE: Problem with my 99 900rr
http://www.spark-plugs.co.uk/pages/t.../diagnosis.htm
Sounds like it's rich--too much fuel, not enough air. What kind of air filter is in the box? Does it need replacing?
If it were me, and nothing else was different on the bike, I would yank those 39's and buy a good set of used OEM 38's.
Otherwise, read up on how to adjust fuel-to-air mixtures (jetting) on carburetors and give it a go...
Sounds like it's rich--too much fuel, not enough air. What kind of air filter is in the box? Does it need replacing?
If it were me, and nothing else was different on the bike, I would yank those 39's and buy a good set of used OEM 38's.
Otherwise, read up on how to adjust fuel-to-air mixtures (jetting) on carburetors and give it a go...
#6
#7
#8
RE: Problem with my 99 900rr
oooooh, thank you for thet diag site, yeah the bike is running way too rich, ill have to adjust the air-fuel jets apperently.
the plugs got fouled rather quick though, because yesturday i just put the bike back together from the same problem before,
and i was running it idle for a bit to let it warm up and what not, and it kept turning off after 1-2 mins on idle. It seemed as
if it were losing power when it happened and so after maybe 20-30 mins of me turning the bike on after it shut off everything,
it didnt want to turn back on so i took out one of the plugs to find it fouled =/.
does anyone know where i can maybe get the right AFR settings for this carb ?
the plugs got fouled rather quick though, because yesturday i just put the bike back together from the same problem before,
and i was running it idle for a bit to let it warm up and what not, and it kept turning off after 1-2 mins on idle. It seemed as
if it were losing power when it happened and so after maybe 20-30 mins of me turning the bike on after it shut off everything,
it didnt want to turn back on so i took out one of the plugs to find it fouled =/.
does anyone know where i can maybe get the right AFR settings for this carb ?
#9
RE: Problem with my 99 900rr
Carb tuning is almost a black art. LOL. It is a lot of trial and error and it takes a lot of time to get perfect.
He is right, without an A/F ration sensor (such as on a dyno) you have to run the bike at WOT and kill it, then look at the plugs to see how they look. They should be a milky brown when the mixture is right on. That will get your main jets set right, but may not fix any part throttle issues (if you have any). Your intermediate jets and to a certain extent your idle jets will play a factor in the part throttle response as well as needle height.
Again, it takes time, but it's VERY hard to beat a perfectly metering set of carbs.
He is right, without an A/F ration sensor (such as on a dyno) you have to run the bike at WOT and kill it, then look at the plugs to see how they look. They should be a milky brown when the mixture is right on. That will get your main jets set right, but may not fix any part throttle issues (if you have any). Your intermediate jets and to a certain extent your idle jets will play a factor in the part throttle response as well as needle height.
Again, it takes time, but it's VERY hard to beat a perfectly metering set of carbs.
#10
RE: Problem with my 99 900rr
ORIGINAL: gixxereater
Carb tuning is almost a black art. LOL. It is a lot of trial and error and it takes a lot of time to get perfect.
He is right, without an A/F ration sensor (such as on a dyno) you have to run the bike at WOT and kill it, then look at the plugs to see how they look. They should be a milky brown when the mixture is right on. That will get your main jets set right, but may not fix any part throttle issues (if you have any). Your intermediate jets and to a certain extent your idle jets will play a factor in the part throttle response as well as needle height.
Again, it takes time, but it's VERY hard to beat a perfectly metering set of carbs.
Carb tuning is almost a black art. LOL. It is a lot of trial and error and it takes a lot of time to get perfect.
He is right, without an A/F ration sensor (such as on a dyno) you have to run the bike at WOT and kill it, then look at the plugs to see how they look. They should be a milky brown when the mixture is right on. That will get your main jets set right, but may not fix any part throttle issues (if you have any). Your intermediate jets and to a certain extent your idle jets will play a factor in the part throttle response as well as needle height.
Again, it takes time, but it's VERY hard to beat a perfectly metering set of carbs.