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88 fzr 750 cutting out.......

Posted: Fri Jul 29, 2011 7:50 pm
by qkenuf4u
got a customers bike here.. not familiar with the 750...

the problem is it stumbles after 6,000 rpm all the way to redline....

it idles perfect and runs nice up to 6k..... it has died out a few times while just sitting there/riding slow.. weak pumk running the bowls dry ?

thanks
lance

Re: 88 fzr 750 cutting out.......

Posted: Fri Jul 29, 2011 9:09 pm
by ragedigital
Have you rebuilt the carbs or torn them down? Might need the needle jet adjusted if a jet kit has been installed.

Re: 88 fzr 750 cutting out.......

Posted: Sat Jul 30, 2011 12:43 am
by qkenuf4u
kid had another bike garage in town go thru carbs awhile back....

im guessing this just uses a pulse fuel pump (diaphram pump) .. im thinking either the pump is weak or filter is clogged... gotta check that out monday... thinking it will pump enough to let it idle but not enough to supply the main jet enough once the needles come up.....

Re: 88 fzr 750 cutting out.......

Posted: Sat Jul 30, 2011 3:12 pm
by DonTZ125
Hi, qkenuf4u.

There are a number of points of potential fouling in the fuel stream on these bikes. There is the outlet screen in the tank, the pump itself, the inline filter, and the carbs. The pump is as you noted a pulse-diaphragm type, and should prime for 5sec when the key and kill switches are turned on.

Have you checked the tank? I know you said the customer had the carbs done recently, but I'm sure you know better than most of us here how fast a dirty tank will pack the fuel system with crap... banghead

Re: 88 fzr 750 cutting out.......

Posted: Sun Jul 31, 2011 12:22 am
by qkenuf4u
DonTZ125 wrote:Hi, qkenuf4u.

There are a number of points of potential fouling in the fuel stream on these bikes. There is the outlet screen in the tank, the pump itself, the inline filter, and the carbs. The pump is as you noted a pulse-diaphragm type, and should prime for 5sec when the key and kill switches are turned on.

Have you checked the tank? I know you said the customer had the carbs done recently, but I'm sure you know better than most of us here how fast a dirty tank will pack the fuel system with crap... banghead
i did some more research and found out where the pump is supposed to be ect... well being theres NO PUMP on this bike that explains why it idles perfect , revs perfect then wont rev above 6k and shuts off after ya ride it a little bit.. the head pressure is able to keep the bowls just full enough to rev/idle but not REV OUT... so ill have to find a pump and find the wiring that it gets plugged into.... (i seen that the R1/R6 pumps work)
ill let the kid know and see what he wants to do... he sunk a $1000 into with the other guy ($1000 for fork seals, a tire, carb clean :yikes: )
tank is spotless inside (thank you arizona)
is there a PDF service manual available on this site ????thanks
lance

Re: 88 fzr 750 cutting out.......

Posted: Sun Jul 31, 2011 1:00 pm
by DonTZ125
A THOUSAND BUCKS - FOR THAT??! :yikes:

That's ... theft. Outright, barefaced, arrant highway robbery. FFS ... :swear


Any 12v carb pulse pump will work. If you get one from an R1 / R6, be sure you get the early carb version, and not the high-pressure EFI version!! lol :drink:

I have a .pdf manual; it's 75Mb... I can't remember where I found it, but it's out there. It's a combined manual, with the same-year FZR1000.

Re: 88 fzr 750 cutting out.......

Posted: Sun Jul 31, 2011 5:32 pm
by qkenuf4u
DonTZ125 wrote:A THOUSAND BUCKS - FOR THAT??! :yikes:

That's ... theft. Outright, barefaced, arrant highway robbery. FFS ... :swear


Any 12v carb pulse pump will work. If you get one from an R1 / R6, be sure you get the early carb version, and not the high-pressure EFI version!! lol :drink:

I have a .pdf manual; it's 75Mb... I can't remember where I found it, but it's out there. It's a combined manual, with the same-year FZR1000.

thanks.. thats the info ive found... :cheers: ......yes i agree that was straight up theft.... esp since the chains wore out and so tight/loose it binds up trying to ride the bike..... and wont rev over 6k... would have never left my shop that way...