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FYI: RK TEK "DROP IN" PISTON AND HEAD KIT FOR PRO 800'S

gmustangt

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Kelsey

Will you offering a turbo specific head to go with the pistons at some point?
Hope you can get it in a turbo this season for some testing.
 
V

v8lover

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Oct 14, 2008
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cannon falls, minnesota
True RKT I was just wondering, but I am very impressed with the custom pistons, and head from what I read really good things on the doo talk forum tonight about the drop in kit, and I bet the same for the pro 800's. I had one other question about the 858 kit, does someone send you the jugs to get done? thank you.
 

Mentzel

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Interested in a kit for 09' CFI-4. Who is manufacturing the pistons? Wiseco?

Anything will be better than the stock piston/head combo. Along with piston clearance issues the stock head is junk. It is clearly shaped wrong and I noticed bad porosity in the castings. I'm surprised the engines don't eat/leak antifreeze.

This RK tech kit looks pretty nice... How hard is it to find the custom pistons when they eventually fail? What piston clearance is used in this kit? What squish clearance is required for pump gas? Maybe I'll just order 2 sets of pistons. They will need replaced eventually...
 

Mentzel

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Also will it work with a SLP full exhaust? Dang I just installed it... SLP offers a head but no fix for piston issues.

RK Tech offers no pipe (yet) for the piston/head kit. All three need to work together for best performance.
 
K

Kestrel2126

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Nov 17, 2009
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Grand Jct, CO
I am also VERY interested in this kit going on my turbo Pro. I called and left you a message friday. Is Compression ratio the same or close? If this kit will work well with a turbo, and you can assure me it will, I'm in!
I've always had great luck with the RKT SkiDoo 860's, definitely willing to give this a shot if you say it's good to go!
 
R

RKT

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Jul 19, 2001
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Kelsey i too would be interested in a turbo head and piston set up. I also have 2 other friends that would be on board as well. Keep us in the loop on the turbo threads


Since I do have some turbo experience ..I was riding turbos in the late 90's.. before most of there turbo companies were even in business.. OVS, set up all my turbos and were ONE of the innnovators in the turbo world. Brad Story and Steve Packer were the other innovators all three of those guys know turbos!!!.. Well,'nuff on that... lol

Point being.. have some good experience with turbos.. In fact, withour patented TURBO SPECIFIC head design you can,usually, run 2-3 PSI MORE boost on the same octane.. Been doing turbo specific heads for a LONG TIME. nothing new for us.

As for these pistons in a turbo.. I see no reason why they would not work well since they add airflow and airflow is what turbos are all about.

Having said all that, I do not ride a Pro turbo so I have no direct experience usingt his kit on the Pro turbo. BUT, I am very confident that it would be a great match.

NOTE: We do have turbo specific heads, THAT HAVE BEEN TESTED, for stock pistons.. They are working very well.. Just no test data on the Turbo and the drop in piston kit.
 
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RKT

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Interested in a kit for 09' CFI-4. Who is manufacturing the pistons? Wiseco?

Anything will be better than the stock piston/head combo. Along with piston clearance issues the stock head is junk. It is clearly shaped wrong and I noticed bad porosity in the castings. I'm surprised the engines don't eat/leak antifreeze.

This RK tech kit looks pretty nice... How hard is it to find the custom pistons when they eventually fail? What piston clearance is used in this kit? What squish clearance is required for pump gas? Maybe I'll just order 2 sets of pistons. They will need replaced eventually...

We are doing no testing on the CFI-4 platform.. While thes pistons will install just fine in the CFI-4, we will not be doing any testing on this platform
 

mountainhorse

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stock works

Also will it work with a SLP full exhaust? Dang I just installed it... SLP offers a head but no fix for piston issues.

RK Tech offers no pipe (yet) for the piston/head kit. All three need to work together for best performance.

I talked with RK Tek about this very topic and here is what I learned.

I agree with you ... all three DO need to work together... his kit "works together", according to him, with the stock pipe and silencer the best

RK Tek did not seen any performance gains with any aftermarket pipe or can with the RK Tek drop in kit on the PRO-RMK platform..
The stock pipe and silencer simply work best with the drop in kit.

This was one of the coolest things to me about his drop in kits that I ran on my REV summit... I didn't have to invest in other things to get the results that I did with his kit.










.
 
V

Vfrtrader

Well-known member
Aug 25, 2009
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Cache Valley, UT
Why would the cfi-2 need this kit (power increase I can see). The cfi-4 motor, yes I can see; however, does the Pro have issues that this kit can fix?
 
X

xc6rider

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Jan 12, 2009
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Why would the cfi-2 need this kit (power increase I can see). The cfi-4 motor, yes I can see; however, does the Pro have issues that this kit can fix?

Looking like their very well could be.... Several popping up with piston and or ring problems it appears. Sounds like mostly '11 Pro models with 1000+ miles. Not exactly sure about any '12 Pro's, but still haven't seen or heard any truth to anything changing internally for the '12 Pro.

Now, if it's a piston or ring problem to begin with, would be hard to prove. But either way, this kit should be an improvement in terms of quality even if the stock stuff is good. Seems to me, the days of just re-ringing to freshen up a topend is getting foolish, and pistons should be done as well.

I'm definitly gonna be interested and keep my eye on these for when the time comes!!
 
T

treedocker

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Sep 1, 2010
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i have rkt drop in kit in my pro and love it, its more snappy than a stock sled it revs quicker and i am pulling 63.5 gram weights at 8300 to 8350 on long pulls and this is at 8k to 10k feet. I am really happy with this kit i now have 600 miles on the sled and 400 on this kit.
i would recommend this kit to anyone out there, it definitely has more power than a stock pro and even a single piped pro with power commander and its cheaper than putting a pipe on your sled, and you gain more performance and reliability.
 

Mentzel

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Now I'm leaning toward an slp head and Wiseco pistons.. I can get those in 2 days if I eat one. And the head and porting are matched up to a pipe. I just need some pistons that are the right size and I'm good to go.
 

Mentzel

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We are doing no testing on the CFI-4 platform.. While thes pistons will install just fine in the CFI-4, we will not be doing any testing on this platform

Stupid...
These are the engines that need work. A guy can buy a new 2010 CFI-4 powered sled cheap now! Very Cheap! With a new top-end a guy could be on a sled for half the price of a pro chassis. Probably even add a turbo and be money ahead of a stock "Pro" chassis. Lots of kits could be sold. Will be tough selling parts for a sled that is not yet broke and has an up front cost of 13k.
 
A

aebsledder

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Jan 16, 2008
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Stupid...
These are the engines that need work. A guy can buy a new 2010 CFI-4 powered sled cheap now! Very Cheap! With a new top-end a guy could be on a sled for half the price of a pro chassis. Probably even add a turbo and be money ahead of a stock "Pro" chassis. Lots of kits could be sold. Will be tough selling parts for a sled that is not yet broke and has an up front cost of 13k.

Or you could say, "Have you considered this". No need to call him stupid. If you read his posts, I would say he is anything but.
 

gmustangt

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Or you could say, "Have you considered this". No need to call him stupid. If you read his posts, I would say he is anything but.

X2 dont know or never met kelsey, but seems well respected and knows his Sh!t.

and for the not needing if its not brok comment.. look at the cost of a pipe($700)..

so for the same ballpark you could have performance gain and a healthier engine...

no brainer to me which i would take, and ill be looking in to this when its time for new top end in the t pro.
 

Dartos

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Stupid...
These are the engines that need work. A guy can buy a new 2010 CFI-4 powered sled cheap now! Very Cheap! With a new top-end a guy could be on a sled for half the price of a pro chassis. Probably even add a turbo and be money ahead of a stock "Pro" chassis. Lots of kits could be sold. Will be tough selling parts for a sled that is not yet broke and has an up front cost of 13k.

Hello Mensa member,

With my normal human brain a thought came to me that there is a chance that Kelsey made a calculated business decision not to perform tests on a discontinued engine configuration.

For those not worthy of your obvious mental prowess I included a link to explain Mensa.

Sincerely,
Dartos
 
A

aja636

Member
Mar 6, 2009
156
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New Jersey
Kelsey, I am a flatlander, I ride around 1500' above sea level. A few years back I had a Fusion 900. I put one of your heads on and it lost HP and performance. Had to remove weight from clutch to get the same RPM. Put the stock head back on and had to add weight back. Tried it with a dyno port pipe as well, and same thing. The pipe itself worked good, 2-3 grams of weight added for the pipe, but the same thing with your head and stock. Although there wasn't a piston upgrade as this kit is, what would have caused that? Or was it that wonderful 900 motor that polaris gave us???

I am very interested in your "kit" for my 2012 800. But fear that these "kits" won't benefit me riding so low in alt. Or if these modded heads are just snake oil, at least in terms of performance. From your last head I used I did notice cooler running temps at least. I am sure your claims and results are true, just would like some honest feedback if its worth it or not. I am running a Bikeman pipe right now with a power commander 5, and that showed good gains, had to add 4 grams to each arm.

I too know that dyno's are just a tool, and anyone can show anything they want on one. Just want to make sure my money is going to make my sled perform better and just as reliable as it has been. If you want to PM me or email me a response that is fine as well.
aj636@mac.com

Thanks
AJ
 
A

aja636

Member
Mar 6, 2009
156
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New Jersey
Everyone else got responses when everyone is praising a product they get all the support. One real question about something gets ignored.
All I asked for is a real answer, not the "It works, go try it"
Thanks, I know my money won't go with this "KIT"
 
R

RKT

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Jul 19, 2001
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Rode last weekend with 3 drop in kits on 2012 Pros.

ALL 3 were set up VERY different in terms of clutching ,exhaust, even heads.. ALL 3 ran very well.. Absolutely no comparision to a good running stocker (yes, they were they in the group as well).

This kit continues to impress all that see it and ride it.. Also fixes some internal engine issues.. Very happy with it..
 
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