carb spring length ?

two-stroke-brit · Post by **two-stroke-brit** » Sun Jun 17, 2018 8:58 pm

Hi All, having trouble starting my new to me 89 fzr1000,
so checking the carbs again.
i had it running once using carb stater fluid .
once started it ran nice.
but now will not start again.
i have a donor 94 bike as well .
i compared the springs and the 94 is 2 inches longer at 6" compared to 4" in the 89.
is this stock and would it help at all to use the longer spring.
also the 94 has no adjustment clip grooves on the needle.
thanks mark

Graham Crayon · Post by **Graham Crayon** » Sun Jun 17, 2018 9:22 pm

cant comment on slide Spring length as they might have been cut & or stretched in a bid to tune throttle response. I would be looking at valve clearances first depending on mileage of your engine. If your certain you're having carb problems then find out setting for air screws & set them then do the same for float heights. Assuming your carbs/jets etc are clean & you have a good strong spark on all cylinders you should get it running well enough to then set tick over & balance them.

two-stroke-brit · Post by **two-stroke-brit** » Sun Jun 17, 2018 10:18 pm

thanks for the advise, it has spark but mediocre at best.it has 40,ooo miles on the speedo. the pilot air screws are 3 turns out. but it has after market exhaust and k&n filters.
i must admit i have never done a valve adjustment before so might have to break my duck on this one.(cant hurt to check them anyway).
i just thought as it started before with help i assumed it would be the choke system.
i should add it hasn't been on the road since 2000.
the carbs are very clean with fresh internals.

thanks mark

Graham Crayon · Post by **Graham Crayon** » Wed Jun 20, 2018 8:40 pm

Before you dive into the cylinder head you could check compression with a tester. I think anything between 140-160 on the gauge is considered healthy. At 40k miles you can expect clearances to be tight if they've never been done before.
3 turns out seems fair for air screws if they have always been like this & the bike ran fine before I wouldn't think there's a problem there.
You say the carbs are very clean. Have they been cleaned since 2000 or do they just look clean?

Post by **Stig** » Wed Jun 20, 2018 9:11 pm

Mine is an absolute bitch to start when it's been stood for any period of time. It eventually goes with prolonged starter activity and no choke, just spluttering into life and revs steadily building until you can Rev it freely on the throttle
Have you tried bumping it?

two-stroke-brit · Post by **two-stroke-brit** » Wed Jun 20, 2018 9:36 pm

thanks guys ,
i stripped,cleaned and rebuilt the carb bank (diaphragms and brass), prior to restart. my plan was to get it running for a bit to get the oil everywhere.
then do a comp test.
cant bump as no chain and sprockets yet(previous were trashed)on order now.
i will swap the coil/ht leads from the donor bike ,just to try that.
maybe i am flooding it with the choke, but its not smelling of unburnt gas.
will also recharge the battery in case thats adding to the issues.
cheers mark