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View Full Version : installing yz 85 motor in polaris predator need help



dadofethan47
02-02-2012, 08:16 PM
I want to install a yz 85 shifter motor into my boys polaris predator 90. The frame has been welded up and had gussets put in by Rath racing. My main concern is the rear swing arm. Are you guys just flipping the carrier and sliding swing arm over? Or custom building them. My other thoughts are a jackshaft. That would make it simple but there would be more rotating mass and 2 chains would be the downfall. The other main reason I am thinking of going this way is. I already have a +2 swing arm and Rath dual +2 arms with custom made C2P shocks. He has been riding his buddies raptor 125 and loves the shifting part. But says it needs more power. And better shocks. And I already bought a 08 yz85 bike for $400 So I have all the donor parts. Any thoughts would be great. Thanks in advance

Logan #34's Dad
02-02-2012, 09:15 PM
If you have the means and ability I'd make your own. But if you have a good solid swinger now, you could use it after some serious modifications.

aarond
02-04-2012, 06:50 PM
I put a rm 85 in our apex after years of cvt havoc.cut the pivot tube off the swingarm ,slip the bolt back in with the pivot tube,cut the two tubes off the roundhouse ,flip the axle over ,reweld the pin for the aluminum brake mounting on the opposite side , have a gear cut from rebel gear to match the hub pattern ,take the wheels off,secure the frame to a table,level it ,set the rear axle level and where you want it ,make shure its square to the frame ,line the chain up so its straight,on both gears,secure the rear asembly,cut new 2x1 x11ga tubes to fit ,tack it all together then weld. I also did the flip on our drr with a ktm 50 motor but your brake will be on the bottom of the axle ,your shock mount will be upside down also ,it does work but doesnt look as nice.you still will have to recut the top shock mount and move it over either way.hope this helps.i can send you a picture tof the drr rear,just text me 203 6153330. i designed a rear shock relocator so you dont have to weld anything ,includes top and lower mount .$55 shipped. all cnc plasma cut

tonnerre
06-06-2012, 12:15 PM
Some pics ???

ken philipp
07-05-2012, 07:27 PM
I did a cr85 in Apex chassis. i simply put the whole swing arm on upide down and moved the shock mounts to the other side. worked great. Dont over think it. The answer is simple.