RMK pro 800 RK tek heads/ pistons question
- Thread starter kurtis.g
- Start date
ditch1000
Active member
2 Seasons on my 2012 Pro... No issues, pulls 2 more grams of weight and never missed a beat!! I had it in at Cycle North on Pr. George last year for the pre-season service; the mechanic said he has not seen a Polaris engine run that smooth in years!!
dragonweld28
Supporting Vendor
DO NOT run that kit. Get the MTNTK kit instead. I only had 800 miles on my kit Rk Tek and I needed new cylinders. It just alters port timing to increase RPM. Clutching for 8500 is a real pain. Call Chris at Parkland motorsports and ask for the MTNTK kit with there billet head. Way better than the RK Tek product. Get your cylinders checked before installing the new kit. They are usually way out of spec.
Wilk INStheWEST
Active VIP Member
Out of spec how? I understand them getting little nicks in them, and the need to be deglazed, but out of spec?
dragonweld28
Supporting Vendor
I didn't see it in person, but I sent my cylinders to get honed for the new pistons and I was told that after the hone they measured to check for proper clearance that they out of spec. Im not sure if it was from factory or what. I do know that my new cylinders and pistons fight much tighter than previous. When I took the old motor apart I had enough space to move the pistons enough to make a clicking noise in the cylinder. I didn't measure them but I know they were really loose.
Rhodesie
Active VIP Member
I have measured dozens of cylinders and they have all been within .001" of each other. how can a nickasel be out of spec. they can't even wear. how can you put wear on a finish that matches diamond strength. your info is disastrous and full of holes. if you couldn't tune your rk tek kit I can't wait to hear what kind of a disaster this one will be. wow!
Wilk INStheWEST
Active VIP Member
That would be the pistons out of spec though. You can't add material back to the cylinders to make pistons fit tighter.
Did you end up getting a new block then?
I'm going with the MTNTK drop in kit on my Pro this year, but when looking at info, the RKTEK website states they have measured 100s of cylinders and all of them have been within spec, and it is the pistons that are out of spec, or warping to become out of spec.
Did you end up getting a new block then?
I'm going with the MTNTK drop in kit on my Pro this year, but when looking at info, the RKTEK website states they have measured 100s of cylinders and all of them have been within spec, and it is the pistons that are out of spec, or warping to become out of spec.
dragonweld28
Supporting Vendor
When you get your cylinders replated you can. This is why I wont recommend the RK Tek kit. Kelsey has some contradicting info out there and I wasnt happy with the overall performance of the kit. It was most likely the pistons. Ya, I had to get a new block.
trench
Active VIP Member
I'm a bit confused with what your saying here, was it the factory Pistons or the RKT pistons that did not fit properly after the honing process? I did the RKT kit and the quality and fit of the Pistons was much better than stock, I never had much time to ride the new set up last year but it's a much smoother running engine now. The stock Pistons were not only a looser fit but there was a 3 gram weight difference between the two!! The RKT Pistons were both the exact same weight and each one was 16 grams lighter than stock. I can't dispute that the MNTK kit is the best one out there if Chrisco is promoting it, but so far I'm very happy with the RKT set up.
dragonweld28
Supporting Vendor
Sorry. The way I wrote that was confusing. The RkTek pistons seemed real loose. I didn't measure them. I got new cylinders and pistons and they were exactly 0.045 clearance. I wish I measured the other pistons. I glad your happy with the kit. I just found that I made the engine very peeky. All I mean by that is it was an all or nothing motor. And I didn't like clutching for 8500. It did run smoother than stock, for sure, I just didn't like the fact that the kit was bragged up the way it was. It doesn't make 12 hp over stock. Just my opinion.
trench
Active VIP Member
Ok thanks for the reply, like I said I did not get to ride it much but seemed better than stock. Did you run stock clutch weights? I opted for the Rooster adjustables, loaded up the heel with as much weight as I could get on them and it pulled real hard here at home, this is with the 13/1 domes.
sledneck_03
Active VIP Member
friend of mines 2011 had the rkt drop in with the 12.5 head for 0-2000 ft but it wouldnt run properly with anything but pure 100ll in it.
weird cause i know people running the PAR 13.1 head under 2000 ft running a 1/4 tank of 100ll.
weird cause i know people running the PAR 13.1 head under 2000 ft running a 1/4 tank of 100ll.
kovs
Active VIP Member
The rk tek drop in really likes the slp pipe and can. I abused mine with 60 shot of boss noss and it's still running. Gonna check it over but felt it pulled harder than stock .
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BILTIT
Active VIP Member
I am guessing he had the wrong domes, i ran 12.5 and no problem. I run 13.6 now at 1800-2200 with 30% 110 no problem.
sledneck_03
Active VIP Member
Rideordie
Active member
My sled had 1700 miles so I did some work. I put the MTNTK fix kit in, the 13.6 PAR head, Dynoport Y pipe, pipe and can. I also went with a 3" x3 camo track and 7 tooth avid drivers as well as a kurts gear down kit, helix and spring. Also some cosmetic **** for that mental HP. I know nothing here is much for horsepower gain but just curious if anyone has run anything similar to this setup. Should run good I imagine. I didn't measure cyclinder bore, just gave it a wipe with the finger and felt nice and smooth lol.
sledneck_03
Active VIP Member
Thats about the same as the slp stage 3 kit, you running a box at all? Where did you get your fuel numbers?
#canadastrong
Rideordie
Active member
No need for the box. That's why I went this route, I would rather not have to mess with mapping. Been down that road before. I will have to run some fuel at lower elevation, compression will be a good bit higher than stock.
