Suzuki 2 Strokes

Hi all, I have a problem that's doing my head in. I have a 75 GT750 that when it fires up it won't idle but just peak rev, I've cleaned the carbies several times,adjusted the floats, new kits throughout adjusted as per manual and still no cigar suggestions greatly appreciated.

Johnny

Have you:

1. Tested for air leaks?
2. Set the initial slide height visually (sewing needle method)?
3. Synced the carbs?
4. Confirmed that your throttle cable(s) routed correctly and not binding up (keeping the slides up when they shouldn't)?

I spent a week figuring that last one out.