Beeze:
My guess is what you are looking for is a pretty small adjustment in the suspension because my 153 takes only six turns of the 3/8-16 track adjuster bolt to go from the front of the adjuster (full slack) to tight. Thats 6/16" or 3/8". you are probably looking for 1/2 that...or less (shorter track and we are talking CHANGES in tension).
Part of the tension problem might be that their isn't enough rail ahead of the front rail axle mount to compensate (add tension) for big hits to the back of the skid... Or when you stomp on the gas at WOT the back has a tendency to squat, and the front to extend. So if there isn't enough of an angle ahead of the front axle mount the track will get slacker..
I'd might try 2 things, and no cast in stone here, merely educated guesses
1. Limter strap: With your current track tensioned the way you have it. Suck up your limiter strap one or 2 holes and see if the track tension changes...it should get looser. I know it will mess up the handling, but its only to test.
If your track slackens noticably in the higher limiter position, readjust to your current tension and test it out to see if it still ratchets.
2 Consider lowering your drop bracket holes. When I lowered my mtx from the upper drop bracket holes to the lower holes (exactly 1 inch), the track slacked off quite a bit, as it affected overall geometry. Similar to above, moving holes might subtly improve the front track angle under power, which affects tension, but I would see this more of a power fix than a trail one.
If solution 1 works, then I'd probably try solution 2, as it is less of an impact on handling.
FYI, my tunnel mounts are 31.25 apart, but I cannot see this making a track tension difference.
OTM
