Howdy guys :D

Right I have been having problems with my bike, well ever since I got it really lol.

Prob I want to sort next is carb related.

It's been getting harder and harder to start off the button, recently it would only start if I bumped it.

However today I gave it a blast of carb cleaner into the carbs and it fired up, however I am still left with the problem that the bike is irratic at idle.

I can set it perfect at home, go for a run and its ok for a while, get to a set of lights and then it just wants to stall, so I turn up the idle and all is well, get to the next set of lights and its revvin its nuts off, I can't win with it.

Today I took delivery of my new carbtune and balanced the carbs, I took video to show you to see if I have done it right, I've balanced carbs before on bikes and always had a good result, am just not sure if the 400 should be all in a line like traditional bikes, you'll be shocked when you check these !

GSX-R 400RR SPII - Carbs Before

http://uk.youtube.com/watch?v=OS5PcA-07cI

GSX-R 400RR SPII - Carbs After

http://uk.youtube.com/watch?v=TfOigfrvHR8

As you can see before I balanced em carb 1 and 4 was hardly registering ! Am suprised the thing started at all.

The after video shows em balanced and for anyone whos done this will know just how hard it is to get em bob on and that is about as good as you will get it, the smallest of turns will make the rods go outta line so I am happy with that.

I took the bike out and ..... nothing beneficial has changed, while the bike was ok to begin with, after I gave it some redline stuff then the stalling at lights problem came back, also I only got 110 down this bit of "track" whereas usually its a 120 mph bit so it seams I have lost some top end and also the bike doesnt feel like its got the same kick

Maybe its because the power is now more linear ? I ain't sure.

I really didnt want to mess with the pilot screws but it looks like I have no choice now eh ?

Can someone confirm if the balancing looks right on the GK73A ? theres nothing unusual about em that requires em to be outta sync is there on the carb tune ? at least if I know I done it right I can move onto the next bit.

Cheers.

Matt :)

Yeah they should be in line matt. Have you had the carbs off the bike and sprayed carb cleaner through all the jets?

Yeah looking nicely balanced now, sounds like you have some fuelling issues there though. Have you put in a new O-ring set in the carbs yet cos theses bikes are notorious for that causing problems with the fuel mixture and bad running?

Hiya guys :)

Never got topic notification email for some reason, didnt know this had been replied to.

I've taken the pilot screws out and there was some corrosion on the springs, so I soaked em in carb cleaner for a good couple of hrs and there 90% like new again, am a bit unsure how much to turn em in tho, before when I tried they just kept screwing in and didnt wanna stop

When I took the pilot scews out there was lots of crud in the threads, gonna give it all a good clean up tomorrow see if it helps things, if not then will get a jet kit and take it from there :D

Not done the o-rings last time I checked they looked ok, will inspect more tomorrow :)

Don't be fooled by O-rings that look ok, mine looked just fine but it still made a heck of a difference changing them.
When you say your pilot screws "just kept screwing in and didnt wanna stop" do you mean the threads are stripped in the body of the carbs? if so they are a bit fooked
If they are ok then you need to screw them in all the way in untill they JUST stop then screw them back out 1 3/4 (I think, can anyone confirm?) turns for standard setting.

Howdy Awynn :)

Thanks for your input mate :)

I took the pilot screws out and soaked em for a good couple of hrs in carb cleaner, all the corrosion that was around the treads came away, I managed to put em back in ok and this time they all seated, must have been the corrosion stoppin it before or me not screwing em in enough.

All done, but need new diaphragms now and at 80 quid, jeez I think I would rather upgrade to a new set of carbs