I posted this on dragbike forum, but figured there's more traffic here, even though there's not many drag racers...
Bike is a '79-80 KZ with Dyna 4000 SP ignition, as well as the Dyna shift minder and shift counter. Previous owner just had it set-up for a shift light and button shift (electric over air shifted) due to their rules. We re-wired to auto-shift with the shift minder when I got it at the beginning of this year. Looking back at time slips, the 1-2 shift was the most inconsistent and threw my ET's off, but it had always shifted every gear. Well as the season went on (still going), it would occasionally not properly shift into 2nd right away. I would feel it kill the ignition at least once before going into gear. Shifts into higher gears would occasionally do this, but the 1-2 was the biggest problem. Eventually it would at times not even kill nor shift and went to redline.
I put a new MPS air shift cylinder and solenoid in for this weekend and that didn't seem to make much difference. The old cylinder did look/feel fairly worn out though...
Yesterday I was planning on swapping out the shift counter with a friend's spare one, but we found that the shift minder 12 volt wire was barely connected and pulled right out. Doh! So after getting that sorted, I did a few test runs at the end of the day. First run was perfect on every shift (best it has ever shifted since I've had it). I had swapped out the the shift counter with the spare, so just to make sure that wasn't causing it as well, I put my old one back in. Well, it shifted all the gears, but not very smooth... So, I swapped back to the spare shift counter to confirm, and that did the same thing as mine now.
Today I ended up just shifting it by foot for half the runs when I knew it missed the 1-2 shift.... I am planning on adding a manual button shift back on, just haven't gotten to it yet.
Just to confirm that the transmission is good, put the bike on a stand and shifted through the gears by hand as well as air shifted (activating the solenoid valve by hand) and they all felt great with no binding.
So, I'm thinking there could be one of two things right now. Either there is a wiring gremlin, or the shift minder isn't working properly. We're about ready to re-wire the entire bike since it is getting pretty old.
Any thoughts? Any more info needed?
