GPZ400R idle problems

[russeleoin]

Hi all. I have restarted on my GPZ restoration and am having problems with the idling. Once warm the bike will idle at 1000rpm but not smoothly. With the filter off I can see the slides almost vibrating or jumping around. Is this an indication of the carbs being out of balance? The reving has a bit of a delay as well, twisting the grip revs the engine but with a delay?
On the plus side, the only other thing not working is the indicators so will fix them this weekend.

Thanks
Russ
____________________
I love classic merc's but bikes take up less space.
Current ride is a Yamaha YB 100 and I love it! Oooow and now a running GPZ400R!
Next stop, Direct Access hopefully by the end of summer.

[SuzukiTom]

Id say they may well be out of balance, are they clean inside? maybe nip the float bowls off and see how dirty it is in there.

Do all the vaccum hoses look OK? also check fopr vaccume leaks around the carbs etc?

also make sure all of the pilot screws (if it does have them visible) are set to manual spec on each carb

asuming the plugs are new?

[philoldsmobil...]

as mentioned above, does sound like carb balance, however, 1000 rpm is rather low. with older bikes I've always found they prefer the idle to be at the higher end, or slightly above the book tolerance, I'd be aiming for about 1400 rpm on the GPz 400 with a fully warmed engine

[SuzukiTom]

also, have you tried running in PRIME / ON and RESERVE to check its not somthing up with the fuel tap - worth a look if it has an inbuilt strainer

[russeleoin]

Due to the state of the tank when I got the bike I put an inline filter in, but you could be onto something as the bowl of the filter does not fill and possibly there is a block in the tap itself. I will check it out. Thanks
____________________
I love classic merc's but bikes take up less space.
Current ride is a Yamaha YB 100 and I love it! Oooow and now a running GPZ400R!
Next stop, Direct Access hopefully by the end of summer.