j900rr

ok heres my problem my cbr900rr breaks up between 5000an 8000rpm i've replaced the following spark plugs and double checked the gap , coils and wires , pep****, fuel lines and filter fuel lines on the carbs had the carbs synsc and checked the floats and jets all are ok and the jets are clean, replaced the fuel pump , also checked the rectafire , it was getting really hot so i checked the harness and saw it was getting a little black ,cleaned all the terminals and replaced the rectafire . then i went through the entire wireing harness to make sure no other wires were damaged all were ok i even checked the resistance of the wires and that checked out ok , the last thing i replaced was the battery just for ***** and giggles and that didnt help , the cdi box is ok swaped it with a another 900rr an it worked fine in that bike????
the only thing i havent replaced is the stator but at this point i dont know if that will help i just dont wanna waste any more money on stupid trail an error parts ,

any help would be greatly apprecated hit me back here or at j900rrr@yahoo.com thanks in advance for any help...

955iDisastar

if its doin it in nutral as well then I think I have seen this before, if its the same thing one of the carb bodies are cracked. Just to be sure... try this, take off the airbox off and try to revv past 5k as your reving put your finger overeach of the little air jets on the top of the carb (smaller brass air bleads) and it should rev once you find the one with the issue.

The 900rr I saw this issue on was droped and the #1 carb body cracked had to be replaced. It would fall as soon as it hit 5k then rev up again... fall ...revup... fall... etc...

blackness

i had this problem when my rr was made into a streetfighter, so i just taped up half of the air inlet tubes and it ran great. if your bike is full fairing then this probably isnt your problem but it worked for me

Paul

Make sure the airbox is seated properly on the carbs,any air leaking by will make it run like that.

up@12

I have that same spit and spudder but it doesn't happen till 7ooo-8000rpms

MikeOnTheBike

that will happen when there is no air cleaner in the airbox. another thing to check out is the kickstand switch, I know sounds kinda funny but that rpm range in the 900's is where most of the vibration is and when my kickstand switch was going out I was getting sputters in that rpm range and I could not figure it out, then a light came on in my head when I came out from a store and had to wiggle the kickstand twice to get it to start. bypassed it and have not had problems since.

93 cbr 900RR for sale. salvage title streetfighter. 62 tooth sprocket k&n air filter, good fork seals, crash cage and scrape bar. the engine just started nockin, there's a little life left. still running. as is $1400

MikeOnTheBike

287ridah

letting her go mike? damn id pick it up if I werent broke as a joke.

MikeOnTheBike

yeah I need to get with the times and get an injected 600. I've been riding this girls 636 at the spot and I'm havin so much fun. I just feel like I am getting held back with that 900 now. tell all your boys it's for sale.

MikeOnTheBike

dude I guess I lost your damn number. I tried to PM you but your box is full. PM me wit the digits. gotta see the new ****, almost got my sitdown both feet on the pegs no handed circles crackin. :YEAH

up@12

I'll try the kick stand thing. I'll let ya know what happens. Thanks