[img]i/expressions/face-icon-small-confused.gif[/img] I just took the DS out this weekend since putting on the Magnum Sand Tire kit and I have no bottom end in the sand, wet sand at least. I have changed the front sprocket to a 15 tooth but that obviously wasn't enough. 14 tooth is the smallest I have been able to locate for the front, what is the largest anyone has put on the rear? Sidewinder is telling me that a 42 is no problem but they have sold 44's as well. Has anyone installed anything larger than the 40 tooth rear sprocket? I don't need this thing geared to go any faster on the top end, that's not my riding style.

 

What kind of riding are you doing? Quick take offs? Casual riding? It seems that I have close to the same mods you have(including the tire kit) and seen a huge increase in the bottom end. One obvious thing is 1st gear is bumping the rev-limiter faster than you can sneeze resulting in a somewhat useless gear for a fast take off. Becuase the time you spend in first gear is cut in half with the mods it does seem like you have lost low-end I find myself starting in second alot more unless I am on hard pack putting around. It is deceiving but second gear on up seemed to clear up my inital confusion of why it seemed like I lost bottom end.
BOMBOWNER[img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-mad.gif[/img][img]i/expressions/face-icon-small-sad.gif[/img][img]i/expressions/face-icon-small-mad.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]

 

I need quick take offs to get some speed up to make it up the sand hills, I'm not talking little hills here. These are steep, easily 100' in height, climbs that require some momentum. Before the Magnum Tire Kit it was 2nd gear climbs (20x11x9 12 paddle Haulers) with it bogging down in 3rd. Now it bogs down in 2nd and shifting down to 1st costs me the momentum I need to keep the tire speed up. Keep in mind this was wet, heavy beach sand, it really puts a load on these motors. I am real close to going back to all stock and putting one part on at a time, which I should have done in the first place. I would have even tried my 20x11x9 12 paddle Haulers had I had them with me. I have already put the stock air filter, needle and carb jet back in thinking it was carburation. I feel even with the stock 20" tires it was geared too high for my type of riding so the 15 tooth seemed like a good option. A three inch change in tire size though is about a 15% change...I only changed the gearing 6.8%(2.5 to 2.67), that's quite a difference.

 

It sounds like you are doing what I would do under the circumstances, being that you knew what type of performance you had before, and the results you have now are clearly from something you have added. I don't know the jetting specs but it seems like yourself and I think Fourlix both having Custom X pipes and changed jetting are still not absolutely confident in your performance outcome, and now having to trace back your steps has to be frustrating. In other posts it seems like the Custom X likes a leaner main-jet unlike my FMF Powercore which seems to work well with a richer main jet. The one thing I have not put alot of thought into that you have is the gearing aspect combined with the performance adds. I hope you find a logical solution to the power loss. Your tests may help me (having the same tire kit) open up a window of even more power.
Good Luck, BOMBOWNER..[img]i/expressions/face-icon-small-smile.gif[/img]