Carbs

[matty8887]

Hi all,

Well heres my problem, i have a yzf750r and was having problems with the petrol consumption and flat spots.

Ive had the carbs off,cleaned them out, replaced the emulsion tubes with titanium ones, cleaned them all out and reset the pilot screws to 2 turns out as stated in the manual and i measured the fuel level and was surprised that it was 15mm!

I set this back down to 7mm by bending the tabs on the floats(they looked new and probably wasnt done when they were fitted)
All four carbs are roughly 7mm like it says in the haynes.

I put it all back together and fired it up, with full choke on it was only on 1.5k revs where as befor it would go to 5k revs on full choke. If there was no choke it wouldnt idle and would stall.

It would idle fine and run ok before i did the carbs, one thing though is the pilot screw was turned out 3/4 time when i first took the carbs out but i reset it to 2 as it stated in the haynes manual but now it runs crap at idle.
Its also a bit noisier than is was before.

Any suggestions as to what it is, i know it could be a few things just wondering what it sounds most likely to be.
Cheers, matt
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Test passed october 2005
Cadburys boost yamaha yzf 750r

[TUG]

But did you walm the bike up and full choke and let it get to a good temp and then set the idle???
Think you missed resetting the idle after changing alot of the carbs.
Did you set the floats on a flat surface? Any mods done to the bike? Exhaust, air filter?
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Haz ER-5, innit!

[matty8887]

Hi, havent been on the net for a week so ill reply now.

I warmed the bike up to full temp reset the idle and it would flutter all over the place, i set the carbs float height on the bike so i know they are correct.

The bike has a sports end can and a k&n panel filter but this was jetted to suit before and i havent changed the jets only the emulsion tubes/needles as they were worn.

As i said the pilot screws on the carbs were out 3/4 turns before but in the book it suggests 2 and then to fiddle about with them a bit which i have a lottle bit but no difference.

The idle wont stay constant really, the petrol has been standing a couple of months though but i wouldnt have thought it would effect it this much?
____________________
Test passed october 2005
Cadburys boost yamaha yzf 750r

[Bru]

Perhaps, after all that work on your carbs, you need to rebalance them. At least, get a gauge to check.

[TUG]

[matty8887]

ok guys, will try that first on the weekend and let you know
____________________
Test passed october 2005
Cadburys boost yamaha yzf 750r