I noticed a while back that my ZXR seemed to have some flat spots when opening the throttle. I further noticed that it was doing around 140 miles to a tank. Is this normal?
Recently it's been cutting out at traffic lights and any time iIgenerally come to a stop and pull the clutch in. Other symptoms have been that if I revved the engine it would happily rev as high as I wanted it to then, when releasing the throttle it would hover at 4 or 3 K then slowly get down to where it should idle, then it cuts out.
So here is what I have done:
1) Replaced Spark Plugs (Previous plugs were indented where the sparks meet the center)
2) Replaced Air Filter (Previous one was filthy with grease, oil and general toad)
3) I've taken off the carburetors and cleaned them all out with Wynns carburetor cleaner. This involved all the linkages for the throttle and choke. Cleaned all the float bowls and checked the diaphragms (all seem ok) They weren't particularly filthy but there was some crud.
4) Refitted the carburetors and screwed in the pilot screws fully. Played around for a few hours and I think I have the right settings now at 3 turns out. Engine starts far better, choke operates better and it does tend to idle well at 15000 - 17000 RPM when the engines warm.
5) Took it out for a spin but it still tends to cut out when it should idle. However it doesn't seem to hang at 3 - 4K when releasing the throttle anymore.
So now I have come to balance the carburetors. I warmed her up, fitted the gauges and they tend to oscilate quite a lot when at idle. However, when revving the bike the needles on all the gauges are reading between the area shown on the picture below:
This reads:
"Late valve timing or leak at intake manifold or heat riser"
So, I did spray some carburetor cleaner on the intakes previously and nothing happened. However I will try this again.
What the hell is a heat riser?
How can I change the valve timing?
What are your opinions please guys, the more the better.
Many thanks in advance for you replies.
Andy.
