My 02 ZR600 power valve servo seems to retract to far back upon closing on occasion which causes the cables to slacken where they wrap around the spool and the first one wants to come out. When I bought the sled the cables were disconnected. When running it with the back end in the air all works properly. I am curious what may cause my issue. I rebuilt the top end with new cylinders last spring and checked cable adjustments and they were right on.
something is adjusted wrong... kccats is correct, there shouldn't be so much cable that it can go back that far. I know when I work on mine the first thing I do is manually pull them up by turning the spool by hand until the cable is tight.
Ok, I am not an expert or I wouldn't be asking for help. I assure you the servo is going back further than it should. I put a mark on the housing and the spool in the retracted position. I then ran the engine with the back up to verify proper rpm engagement and that the servo returns to normal. All was well. Seems to do this only occasionally.
I apmit I've seen several different adjustment numbers, but if you adjust them equal and 'Loose' the motor should just turn just so far?
Personally I have the Supreem Tool Vac operated valves on my Big Cats, and my ZR has the BM Invader vac valves(DOO style!)
So I tested the servo motor resistance per the manual and also fed voltage in both directions. I think the resistance is flakey as I can get an intemittant open at lower readings though I am not popping any codes. Any way I did modify the pulley and installed my own retainer to stop the cables from coming loose and causing additional issues that are avoidable from a less than desirable design. This at least will stop potential cable damage. I need to get it back in the air and run some tests. Could have a sticky valve though this is fresh top end and I spent a lot of time on the valves to make sure I had no issues.
If put together correctly you cannot drop the valves in to far as the valve stopper limits this travel. The one thing they did do correctly with this system is not make the cables the limiting factor for interference or they would have a lot of issues. The cables are adjusted per the manual. I did just as smoking crater stated to ensure the cable lengths are correct.