www.zxrworld.co.uk

Hi guys.

I am currently restorring a Zxr400L1. I bought it cheap from a breaker, not knowing the history/condition of the bike.
I just fitted a new CDI, new spark plugs, new fuel and air filter.
Cleaned the carbs the other day.
I then mounted the carbs, pulled the choke lever to fully engaged and pushed the starter. When the carbs were filled, the enginge started instantly.
But during warm-up the engine cycles alot up and down, from 1000 to 4000rpm. It dies when i use less than 3/4 choke. When i turn the throttle it dies unless i let go of the throttle.

S0.. i am convinced the problem is relating to the carbs. But where do i start?

air screws are set to 2 1/4 and 2 3/4 from full in. Haven't touched them. Needles are standart and clean, they move freely up & down. Jets are clean.

Hope u can help...

Have you checked for air leaks? The rubber mounts can perish, spray some carb cleaner around them and if the revs change there's a leak, also the pilot screws sound too lean, 2 1/2 is about a turn extra than standard, you could try that aswell

So..I adjusted the swimmer hight and airscrews. Engine runs alot better now, and does not die when i turn the throttle.

But carb 1&2 leaks petrol from the overflow, could this be caused by wrong swimmer adjustment or is it a worn swimmer needle/valve?

I just ordered 4 new valves from ebay, just to be shure. Im excited to see if this cures my problem?

Swimmer? I'm guessing you mean float height? And yeah, check there all around 11mm