running problem

[mjt-fzr-88]

Probably my own stupid fault this but i'm lost with what the problem could be.

my 1wg is running very rough but only through certain rev ranges.

it was runnin like a carb float was getting stuck as the revs would stick at 3000 but then drop to the normal 1400 idle speed. it got to the point it was sticking at about 4000-4500 and then dropping to normal.

i decided to give it a carb clean, so i took the carbs off, cleaned the float bowls out and spray all the needles.

i've put them back on and now it's running like a bad of crap.

If i only half throttle it's like running through a flat spot and if i open it up it will pull like normal, it sounds different from it's usual tone but it's all the way up to 5000-6000, beyond 6000 the can is too loud to hear anything coming from the engine.

Any ideas what could be wrong or is there anything i missed?

also where is the mixture screw/s on the carbs? i don#'t really wanna take the carbs off again, i might end up with a dead bike.

thanks in advance for any help

[toosmooth]

I had a post carb cleaning issue with my FZ750 that sounded really similar to this - to cure it, I had to do the following:

I took the carbs apart and did 2 things, you can decide which is best for you, but no. 2 is probably the first port of call:

1. based on the fact that with the thing running with the airbox off, so I could view the carbs, I could see neat juice being blown into the venturi from an overflowing jet, I lowered the float heights (I have actually posted a video of this on youtube I'm lost as to where the link is right now though) I thought I had no reason to adjust the float heights, I was wrong, I did and making this adjustment gave this bike it's life back.

2. I disassembled, recleaned and made sure that all the float valves were located, seated and sealing properly.

It appears you can get that little clip device that joins the float and the valve attached wrongly, causing problems.

To gauge the effectiveness of these remedial works, the way I actually checked this was quite innovative and very effective - blow into the fuel feed pipe with the carbs off held in your hands, as you do so gradually tilt the angle of the carb bank so the floats tip up to a point where the float valve seals; you'll feel the back pressure increase as you do this until you eventually simply can't blow past the float valves - proving that they are sealing!

If you do these and still have the same problem, then it's probably not the carbs, but by the sounds of it, it is.

I'm sure others will chip in with their experiences, but fresh from this happening inside the last month, this is mine, for you number 2 is the best thing to check first off.

good luck fella!

toosmooth!

[Evilchicken0]

Hmmm ... I bet it's something easy (ish)

Only ever clean the carbs one at a time, work slowly and methodically.
Did you just undo the float bowls and clean them or did you take any jets out ?
If you took the needles out then take the tops off again and make sure the washers are on the right side of the needles and be careful with the diaphams in the top.

Don't alter the mixture as it's most likely something you moved in the carbs

[mjt-fzr-88]

thanks for the replies guys, will hopefully be able to have a look tonight :)

[mjt-fzr-88]

Think it's all sorted now,

Took all the carbs apart and blew the shit out with a compressor, checked there were no holes or splits in the diaphragm and it seems now to be working, only taking it to the top of my street and back though.

thanks for the info guys :)

[toosmooth]

If only carbs were as maintenance free as fuel injection they'd be bloody perfect.

If only fuel injection delivered smooth power like carbs it'd be bloody perfect.

buggered either way.

hope it runs well when you've left the road near your house!!

toosmooth!