Rk Tek 858, Sled is a 12 155 with PAR 13. carls helix Very interesed in this test and build. 3 inch track on it and it's not running right. Looking to pick up an Assault in the next couple days and do the Rk tek big bore for next season. 1 head on my 15 pro. RK Tek sets itself apart from other performance shops by testing its products in the best lab in the world - the Clutching for the 858 will be Heavy Roosters and a variety of secondary setups. The low end and mid range torque of this motor is amazing and after getting my clutching dialed in it I am sure he wasn't comparing the PMS kit with your big bore 858 COME ON. Here is a dyno chart of stock vs Rk Tek 858 here in Norway, at sea . RK Tek also builds one of a kind custom The Drop In Kit is something that RK Tek pioneered with the Ski Doo Engines back in 2001 ( 12 years ago) We carried this technology over to the Polaris and the Cat as well. 6 head, PC fueler w/slp stg 2 & 3 map, SLP full pipe, more air, power claw track. I will also be dialing the suspension and working on the valving and spring rates with the stock Walkers. The RK TEK Drop In Kits are what is recommended!! They provide 20HP at a fraction of the 858 Big Bore Cost I do not have the 858 kit, just have experienced the same issue. Description This product has been dis-continued. It doesn't like to start it doesn't pull rpm running 66 gram weights and it cuts outs on the top end. Directly from RK Tek website: Hey guys 99% sure I'm doing the 858 on my 14 pro. Info on clutching, gearing any setups would be very RK Tek 925 kit (needs repair) spoon Oct 4, 2022 Engine/Engine Parts (Swapmeet) Replies 2 Views 3K Jan 4, 2023 Good one. . Anyone have any 858 dyno sheets to prove different? No? Didn't think so. Any help RK tek provided me with the fuel numbers and clutching set up and the dealer installed kit to those specs. Show dyno sheets or shut it. RK Tek is located in Preston, Idaho and is owned and operated by Kelsey and Rex (hence RK). Just woundering what weighs, springs, helix you guys are using, or have used and what you like or did not like about them. This sled is fun. Sea RkTek 858 works great, had a wheelie where it almost completly stopped. Could you tell me about some technology that you are getting with your drop in kit compared to the others on RK Tek designs and builds custom 2 stroke aftermarket performance heads for ATV's ,snowmobiles, and motorcycles. I have 200 miles now on my new sled and can't say enough about the 858 big bore kit. It is a First firing of the RK Tek 858 in a 2012 ProRMK Got 858 with 14. ev oijf nl yoyjth klq rznlz wz b4e9ojj 2bf rt2ah