not a gs but a gsxr question.

[Jesse002100]

i hope you guys can help, you have got me thru all other issues.

i got my 98 gsxr 600 about a week ago and all was fine.
now when i take off it has no power till about 3000rpm and just putter and shake alot till then as well as if i let off the throttle it stalls.

i reset the carbs to factory settings. i cleaned the pilot jets and everything and set the mixture screws to the manual's specs at 3.5 turns out for cylinder 1 and 4 and 2.5 turns out on 2 and 3.
the bike still bogs on take off till 3k rpms.
when the engine is cold say under 130 degrees it doesnt bog very much at all if any. it seems like it only is really bad at normal temp 165-180
above 3k its great tho...

does anyone have any thoughts on what can be wrong? ill try anything.
thanks, Jesse

[chuck hahn]

why would 4 identical bore cylinders require two different amount of fuel/air mixture??? that somehow just doesnt sound right to me. I dont have a GSXR buit still that makes me wonder. Are two of the cylinders a different bore than the other two...

[skreemer]

why would 4 identical bore cylinders require two different amount of fuel/air mixture??? that somehow just doesnt sound right to me. I dont have a GSXR buit still that makes me wonder. Are two of the cylinders a different bore than the other two...

because the "inner" ones get hotter... On most the GS's I've worked on the "inner" two were different than the outer two... At least in the factory manulas they are set different, in most the Hayne's and Chilton's manuals it's the same across all 4.

[chuck hahn]

sooooo..maybe richen the two inner ones a bit and see what happens

[Jesse002100]

i set all of them to 3.5 and tested it and at 2.5 and tested and 1.5 and it was the same. the mixture screws only control one of the pilot jets and idle bottom end till about 3k when the butterfly is just cracked. there are three un adjustable pilots and one controlled by the mixture screw. all of them are clean i took them off and did them twice. replaced the air filter, fuel filter and spark plugs the fuel pump is working.

is there any other thoughts on what can be wrong with it?

for the guy who asked about the mixture being different here is the specs from the service manual i highlighted my bike

thanks for the help so far, gixxer and all those other forums are stumped hope i can get it ready there is a bike run here in cleveland next sunday and hope to ride it.

[1978GS1000custom]

it kinda sounds like its got a leak somewhere. check all the vacuum hoses and carb boots ect.

[Jesse002100]

it kinda sounds like its got a leak somewhere. check all the vacuum hoses and carb boots ect.

there is two vaccum sensors on the carbs that are bypassed and there is a hoses that come off each carb but they just go to eachother and it could be wrong but untill a few days ago it was fine so i am assuming that thats not the issue. when i took off the carbs the boots were in good condition no dry rot or anyhting.

[Jesse002100]

BUMP for the early morning people

[fenderfreek]

Did you check the carb sync? Maybe the locknut came loose or something?

[SqDancerLynn1]

the hoses that you say go together may be vent hoses ?? Try unplugging one end?? Also what air filter assembly do you have? stock ?

[Coady]

Guess I gotta ask what the plugs look like? Just to confirm that its running rich as it sounds like. Then go from there.

[Jesse002100]

well thanks for all the ideas... yesterday i synced the carbs they were already good. one of the float heights was off adjusted it and to someone elses idea i turned the miture screws to 2 turns out and it runs better still has a slight bog not as bad. the plugs are a bit dirty and at WOT it leaves some rich smoke behind not too much but its good i think.

[Jesse002100]

is this the sump jet you spoke of? there is a jet here and a air screw.

[Jesse002100]

shes running good thanks to the collective effort

so i adjusted the mixture screws and the cleaned the sumps to the carbs they were a bit dirty. after that i raised the floats and then cleaned the ignition plate. now its pretty good no complaints anymore maybe a little bit in the transition from pilot jet to main but not a issue as of now.

thanks again for all the thoughts and ideas they helped alot when i was fresh out.

PS. sorry about the red light i got plenty a few get outa jail free cards. my brother and uncle are cops in my home town.

[Jesse002100]

Don't understand why you cleaned ignition plate, as I know nothing 'bout this bike other'n it's a zuk.

Is your main jet pilot valve adjustable?

Are your floats plastic?

plastic floats floated in a bowl of gas for 20 min they float good and the pilot jet is adjustable. there i believe the mixture screws i have them set at 2.5 tuns out and i think the slight slight transition issue is float height related.