with a pair of needle nose pliers you can get under the return spring tail that is on the post in the above pics that has the index mark on it. then pick up spring and wrap tighter around post. I did a couple times and works fine now and still have full rotation of cam arm.
on the xfire only had to remove hood, air box, and sleeve between air box and throttle bodies. easy to reach the return spring with needle nose pliers thru the bulkhead where the sleeve goes.
This was what I did. Fixed it.
Also lengthened the rod two turns while I was in there. Yielded a perfect 49.6:1 ratio.
NOTE: Before lengthening the rod you need to monitor the ratio carefully, as every sled can be different. Then run some pre-mix as a safety precaution while you recheck the ratio after making the change.