RK Tek drop in kit

[mountainhorse]

I didn't re-load the page since post 14 before I asked in post 19.

I've also seen some posts where 'drop in' kits were confused with 'replacement piston' kits that don't have a new head and dont run a fuel box.

I'm looking for information just like others out there. As a mod...I like to be clear that we are communicating well and doing an "apples to apples" comparison.

These are the reasons I like to be clear.

I have some seat time on the RKT version-1 drop in with the BD fuel controller and Head... I ran the team rooster weights and stock exhaust... gearing was changed to 20-44 on a 155 track running at 7000 - 9500'. This is a good friends sled that lets me borrow his ride (I help him wrench on it from time to time... especially when he finds a tree!! (Sorry Chuck)

Next to the stock 800 155, with the exception of clutching and gearing on this "stocker", .... the RKT had considerably better power. I'm considering a Version 2 soon for a custom build PROJECT-PRO that I may pick up this weekend.

VOHK's results with this kit are what is peaking my interest as I really respect his work and product choices. A top notch local rider, Kris, that rides for Boondockers videos... has the Version-2 in his sled and has done very well side by side with some of the big bore PRO's he rides with.... He is not a 'tuner' and has it pretty dialed in... It was a VOHK install on a new sled.






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[pus1100]

rktek drop in kit

Anyone who knows what the correct shift rpm is on 2013 with rev2 kit?

 

[geo]

That's what the OP wanted to know. If it was noticeable.

There are going to be a lot of "old" Pro's out there in top condition chassis wise because they are well built from my experience. Especially if there is a face lift in '16.
Adding HP to the "others" level and durability will be a no-brainer for some. We all just want to know "is it the truth" lol.
More posts make it more likely.

Kudos to RKT to continue to work towards that end.

 

[edavis0202]

I ran a Drop In kit on my 2013 from zero miles on it. I used a SLP Stage 4 mapping as a base and had to actually add fuel to almost RPM range. I could easily walk a stock PRO and any other stock snowmobile. I ran against a stage 4 SLP and beat it 2 out of the 3 times. I think the Drop In kit is by far the best mod for the money on these PROs. There isn’t a pipe or head combo that will get close to what it does. Loved it so much I did RKT 858 this year and love it even more.

Said all that, I think people expect too much out of their simple bolt on mods (pipes, heads, pistons). 10hp isn’t going to give you night and day results. What I see a lot of times is people not doing the entire setup correctly or going cheap on other parts. If you want to run this kit, talk to a shop like Supreme Power sports or Vohk, that has fueling and clutching figured out. They test everything as a package and know what works.

My $0.02

 

[geo]

Sounds like you noticed "night and day" difference e0202. And MH. And Rev 2 runs with big bores.

So,, do these kits really need 8400 to perform? Is there still more power if you screw up and clutch closer to 8100 too?

MH. what was the shift rpm during you seat time?

 

[gman086]

Anyone running the drop-in kit with Carl's clutching? Curious as to how it does with that helix. I'm guessing it should work great as long as you're weighted to get 8400 rpm (and yes, with Kelsey's kits (with his head) you need to spin high rpm's from reading 8 years worth of posts about them).

Have FUN!

G MAN

 

[edavis0202]

Sounds like you noticed "night and day" difference e0202. And MH. And Rev 2 runs with big bores.

So,, do these kits really need 8400 to perform? Is there still more power if you screw up and clutch closer to 8100 too?

MH. what was the shift rpm during you seat time?

To me running a turbo is night and day difference. And YES, there is power left on the table at 8100rpm

 

[boots1031]

Im currently running rktek drop in kit, with carls helix, and epi bellybusters at 68grams on my 13 pro 800 at low elevation. feels a lot more snappier than it did stock. I ran it stock with just the helix at first sled felt a little more snappier on bottom end.. then went and put the rktek drop in kit and now has a lot more bottom and mid range.

 

[bryceraisanen]

Sounds like you noticed "night and day" difference e0202. And MH. And Rev 2 runs with big bores.

So,, do these kits really need 8400 to perform? Is there still more power if you screw up and clutch closer to 8100 too?

MH. what was the shift rpm during you seat time?

I ran mine 8400-8550. Lots of climbs holding right at 8500 steady. Not afraid to wind er up tight lol. Anyway, ran ski to ski on multiple looong uphill pulls with a 2007 summit 860 running high compression and a SPI pipe among other things. This 860 was set up by a "professional" shop who manufactures the components of the 860. This has been the sled to beat in my group for four years, and I'm gonna absolutely destroy it next week with my 858 if I can get er clutched.

Sent from my SGH-M919 using Tapatalk

 

[geo]

Good info.
Yes I've read about the higher rpm in the past but with more out this season I was WONDERING if some ( especially the average Joe) had tried lower rpm and felt the improvement too.
You know like some feel best at 8000 stock and some feel best at 8300.

Seems to work best at recommended rpm. I can't put my head around spinning a twin at that rpm lol so I'll do something different during this summers tear down.

 

[rmscustom]

Me and a bud got up higher than usual one day plus the snow was deep and heavy. I was pulling around 8150 with the DI kit and he was pulling around 8000 with a stock 14 other than Kurts gear down kit. We switched sleds a few times throughout the day and both agreed the DI kit was noticeably stronger than the stock motor. But at that rpm you are leaving some power left on the table with it.

 

[mrkimbell]

i feel mine runs strong at 8200 up to 8400 (ive never clutched down to 8100 with this kit) then i feel it tips over rather quickly if u run any more rpm and ive verified this running side by side with another sled not just my butt dyno are you leaving some on the table at 8200? maybe but it sure doesnt seem that way to me and i am in the camp of 8400 seems like an awful lot for an 800 for me this kit made this sled perform like an 800 should

 

[bryceraisanen]

Just wondering guys... is there something specific that makes u not want to run higher rpm? I know generally speaking most 800 stockers for the last decade run in the 79-82 rpm range, but is there some unwritten rule as to max rpm? Some motors run double that... of course you dont want to be overreving outta the powerband... I usually clutch toward the top of a given powerband as best as I can, cause when out riding for real, you stay in the power longer when climbing etc.

Sent from my SGH-M919 using Tapatalk

 

[IAMNOWHERE]

Sounds like you noticed "night and day" difference e0202. And MH. And Rev 2 runs with big bores.

So,, do these kits really need 8400 to perform? Is there still more power if you screw up and clutch closer to 8100 too?

MH. what was the shift rpm during you seat time?

There is a noticeable difference when clutching. I have the Drop in Kit with the Team Rooster Adjustable weights. I have been messing with them shifting weight around. I am always looking to find just a little more. I find the sled pulls the hardest when its running 8300 to 8500. I had a little too much weight and was only getting around 8050. It still ran good belt felt more like a stocker. I pulled a little out of the belly and a little off the tip and it was pulling like a freight train again.

 

[tatorsalad]

Rkt drop in kit

How are they running thinking about putting one in my 2015

 

[Reddragon800]

Don't waste your time...... Get the Fix kit from MTNTK performance. Or get there head and fix kit combo.

 

[mountainhorse]

Merged the threads to this existing one on the same topic.

If you are new to this topic... benefit from reading the entire thread above (2 pages) ... add to it where/if you can in a meaningful way... and come to your own conclusions.

I've had good luck with the RKT replacement pistons and the Drop in kit with the head.

I've also helped a couple of people this season that had run-ability issues with their kits that boiled down to 1 leaking base gasket and both needing tuning (controller and improper clutching setups).

There are a few kits out there to choose from now... most with quality setups... I've found that the common denominator of weather or not the sled ran well is if it was installed correctly, tuned properly AND with no pre existing clutching / fuel /ignition issues... some memebers I've chatted with through PM's/emails have had issues with the different kits and it boiled down to the fact that the sled ran poorly before the kit was installed... a out of tolerance cylinder, faulty injector, plugged fuel filter, worn-thru spark plug wire, bad reeds etc... If your sled is not in good general health... then none of the kits will help out (I of course exclude worn out pistons or cylinder issues that should be addressed with the installation of the kit)


Good luck... and rock on!!

Pray for snow... most of us need it.






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[NDFARMER95]

I feel the RKT drop in is worth it. Installed it on my 13 standard from brand new. Turned the oiler to 32:1. 14.1 comp head, slp pipe and can, PCV, Rooster adjustables, SPS clutching, F-bomb track mod, and ez-ryde. Flat out rips in the trees. 66.8g pulling 8350-8450 at about 8000 feet last trip in West Yellowstone.

 

[trey4x4]

150 miles on drop in kit, '11 Rush PR. Took a couple tries to get clutch dialed in. Jumps to 8500 and holds steady around 83-8400. Checked top speed recall, 109 on flat road with couple inches of fresh powder. Pulls hard on the hard pack and holds good rpm in the powder. Stock pistons had 1100 miles and looked ok other than how loose they fit in the cylinders. Very happy with the kit and looking forward to what RK Tek is coming up with for the 600.

 

[rmscustom]

I feel the RKT drop in is worth it. Installed it on my 13 standard from brand new. Turned the oiler to 32:1. 14.1 comp head, slp pipe and can, PCV, Rooster adjustables, SPS clutching, F-bomb track mod, and ez-ryde. Flat out rips in the trees. 66.8g pulling 8350-8450 at about 8000 feet last trip in West Yellowstone.

That's a lot of weight to pull... What length track? How do you have the roosters loaded? What gearing?