Only running on choke.

Hi guys, I've got an old kz750 h2, which was stored for 6 years. I have fitted a new dyna s ignition system and coils. Previous owner said carbs were serviced but I'm doubting this. The problem is the bike starts and runs fine on choke, but as soon as the choke is dropped down I get a sort of cam chain sounding rattle and it dies. I think I need to strip and clean the carbs but could this also be the cause of the rattle? I'm guessing if one or more jets are blocked it could cause this. Any tips?
Cheers
Pete

What rpm is the idle set at? Ed

hi ed,

Idle a bit tricky to set, thats why i'm thinking carbs still a bit gummed up. I can adjust with choke on but it dies as soon as choke is turned off, even blipping the throttle it still dies. Runs fine on choke though. Tried setting idle with choke at 3500, still died when choke turned off.

Cheers
Pete

I agree. It sounds like cleaning the carbs is the next step. Ed

Cheers ed, looks like a job for the weekend
Pete

Well, stripped the carbs, no 3 main was caked with crap and all the others had blockages everywhere. All now spotless and running without choke so problem No1 gone. Next is the low rpm rattle, think its the cam chain tensioner as its an unreliable automatic one.
Still happy the carbs are done.

Chain may be rattling from carbs out of sync. have you done a Running Dynamic Sync, with a Manometer? this may quiet it down if it is noisy at Idle.

Thanks motor head, will try this next, still don't trust that auto cam chain tensioner though.
Pete