My RKT 858 experience
- Thread starter IQRIDR
- Start date
And this would be exactly the reason (excessive cylinder bore distortion) Struther's has chucked the 800 CFI Monoblocks in the trash and uses custom built cylinder's for his 860 (CFI-4) and 900 (CFI-2) Big bore kits.
Yes it does, many things can cause it..slightly too tight of a bore to begin with(on the cfi4 motors polaris kept adding piston/bore clearence to try and alleviate this issue, problem is the looser the clearence..the more the piston beats the skirts to death.., to thin of a cylinder sleve(thin to begin with and now its been over bored right?), too lean of a fuel mixture, too fast of a heat up(jumping on cold and railing the throttle), can heat and swell a piston faster then the cylinders causing it to squeak, rings located to far down from the dome(can make the dome hold to much heat causing the piston to swell more)since the rings are there to seal the piston to the bore, but also to transfer heat from the piston to the bore wall where the coolant can take it out of the motor,ignition timing can cause it as can too small of a pipe outlet..tons of things can..as can any combo of the above....
I would be pulling the head and having a good look myself...
which is why if I was doing a big bore on a cfi I would be doing carl's kit...they have already been thru it before....
T
TurboMatt
Well-known member
ya, I don't get that either.
hm...if im swallowing a test series laxative i would expect the possible unintentional messy discharge
P
pura vida
Well-known member
really? he didn't bash it, just gave his experience with it. as I understand it, it was presented as a field tested and proven setup that just needed some low elevation tuning/mapping to dial it in so it could be sent out to customers. and Kelsey, those were your supplied cylinders and pistons, not something bought off the shelf or selected at random. so if this situation is not unexpected why send it out? or were you using this as a testing platform to see what would happen? no one, in any way, is all out bashing RKT or kelsey directly. in fact it was stated that it has good potential and showed great promise but clearly still has some issues to work out. who knows, its possible this is an isolated incident and there is some sort of tolerance issue with this specific setup. no one is stating this is an issue with every 858 kit but rather stated the experience with this specific one. don't shoot the messenger simply b/c you don't like or want to hear what he is saying.
pv
K
knifedge
Well-known member
--IQRDR mentions in the second to last paragraph that this was a "one-off kit". With a "one-off kit", I would think by receiving those parts and installing them on your sled, you would be taking a higher risk than normal when it came to reliability and tuning. Apparently, he knowingly installed expermimental equipment on his sled.
--Also, the part where it was previously mentioned the kit was a "prototype" has been edited out.
--Quote--
Normally I would have continued to keep all this to myself but I feel morally obligated to the industry and my shop's reputation to put the facts out there and let them speak for themselves. This kit DID RUN GREAT but it does have problems that need to be addressed and to be honest I am sure RKT will address them and have a good running, cost effective bang-for-the-buck kit. This was a one-off kit.
--Also, the part where it was previously mentioned the kit was a "prototype" has been edited out.
--Quote--
Normally I would have continued to keep all this to myself but I feel morally obligated to the industry and my shop's reputation to put the facts out there and let them speak for themselves. This kit DID RUN GREAT but it does have problems that need to be addressed and to be honest I am sure RKT will address them and have a good running, cost effective bang-for-the-buck kit. This was a one-off kit.
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K
knifedge
Well-known member
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First off, I want to make it clear- I am not bashing a product here. I am posting my objective experience with a product. Lots of people are asking and contacting me regarding how the kit ran and I, as a long time member here on Snowest and a shop owner I feel obligated to set the drama aside and simply post the facts.
When the 858 motor first got out on the snow, it ran great once the fueling was dialed in. Pulled massive track speed, motor sounded very healthy, everything was good. Then, I lost a rod bearing after about 50-60 miles. Crank was done. At this point, the sled needed a new piston on the mag side (mag rod bearing scored it up) but already had some scuffing on the PTO piston as well. This concerned me but I was assured that it could be run again once it was cleaned up a little with a scotch brite pad.
The cylinder also had some interesting scoring...I have my opinion about it, RKT has theirs, I suppose the cylinder plating company would have one also. I will let you form your own.
I then rebuilt the motor with a new crank and 1 new piston. It ran great, again, for about 5 rides or so, then started losing power and compression slowly. I dissembled the motor to find 2 heavily scuffed pistons and the cylinder looking and feeling worse than before.
I believe that there are some problems with this kit that can most definitely be solved, but it has been brought to my attention that people are being informed that the sled ran great for a lot of miles and is still running. The 858 kit got a total of just under 350 miles on my sled the 2 times it was installed. I have since reinstalled a stock cylinder and pistons with my previous head and pipe setup. I do not want people to be misled or under the impression that the kit had no problems. I will be sending the pistons back to RKT for inspection.
Normally I would have continued to keep all this to myself but I feel morally obligated to the industry and my shop's reputation to put the facts out there and let them speak for themselves. This kit DID RUN GREAT but it does have problems that need to be addressed and to be honest I am sure RKT will address them and have a good running, cost effective bang-for-the-buck kit. This was a one-off kit.
I want to make it clear that there is nothing wrong with the sled as far as snow ingestion, belt dust ingestion, oiling, etc...a picture of my stock piston with 2438 miles on it will attest to that..no significant scuffing or wear, in fact they looked pretty decent and still made perfect compression.
Stock piston, intake side (STOCK 2011 PISTONS, THESE ARE NOT THE 858 PISTONS)
Stock piston, exhaust side
RKT 858 cylinder
Inevitably there will be people bashing me or disagreeing with my choice to post this here...but I got into this business for a few reasons with a set of specific principles and morals and I do not want to be responsible for people being misled or misinformed. Flame away.
How about not bashing these guys and look at the source POLARIS . If they could build a dependable engine we would not be having this disscussion. I for one was asking for more info on this kit because I knew Carl's changed to cylinders instead of the mono block but was hoping since it was a 860 instead of a 900 the price would be affordable .
How did it get this far did Kelsey know Chad was having issue??
How did it get this far did Kelsey know Chad was having issue??
R
RKT
Well-known member
You know it is funny how everybody gets caught up in the “drama” on public forums.
Whenever there is a “positive” thread about a product it gets little notice or response.. BUT.. the instant something “unfavorable” arises.. WOW… different story.. Tons of responses and NOW all the “Assumptions” and “Speculations” and “Hear-Say” etc. etc. etc. start to surface .
Then many take it to the next level and start injecting comments like “why would he do that” and “What a bad product” etc. etc. It just goes on and on..
You know the old saying where you tell 1 person a story and then you have that person, immediately, tell 10 other people the SAME story they were just told ?
Then you ask the 10th person for the story… and, guess what, the story has things added and missing and usually has a totally different meaning all together..
Well.. this obviously rings true with public forums and this thread is a great example of that…
So, all this speculation on what happened and what did NOT happen is just thatà speculation .
So, I suspect all the speculation and assumption and what not will surely continue and, yes, I will check in to view it..
If I were to start a thread staing that my neighbor just saw Big Foot.. that does not mean that he actually just saw Big Foot.. It just means that I “Heard” he saw Big Foot… and the thread would grow and grow about other Big Foot sightings and Big Foot killings and mutilations and so on and so on.. And pretty soon Big Foot would be seen everywhere raping and pillaging. And the real point of the thread would be long gone with all the hear-say that was introduced.
So, keep in mind, things are not always what they seem and like all public forums, you need to take it (any information) all with a grain of salt. Otherwise you will be taken in by all the BS! In the end, the real story usually comes out!
Whenever there is a “positive” thread about a product it gets little notice or response.. BUT.. the instant something “unfavorable” arises.. WOW… different story.. Tons of responses and NOW all the “Assumptions” and “Speculations” and “Hear-Say” etc. etc. etc. start to surface .
Then many take it to the next level and start injecting comments like “why would he do that” and “What a bad product” etc. etc. It just goes on and on..
You know the old saying where you tell 1 person a story and then you have that person, immediately, tell 10 other people the SAME story they were just told ?
Then you ask the 10th person for the story… and, guess what, the story has things added and missing and usually has a totally different meaning all together..
Well.. this obviously rings true with public forums and this thread is a great example of that…
So, all this speculation on what happened and what did NOT happen is just thatà speculation .
So, I suspect all the speculation and assumption and what not will surely continue and, yes, I will check in to view it..
If I were to start a thread staing that my neighbor just saw Big Foot.. that does not mean that he actually just saw Big Foot.. It just means that I “Heard” he saw Big Foot… and the thread would grow and grow about other Big Foot sightings and Big Foot killings and mutilations and so on and so on.. And pretty soon Big Foot would be seen everywhere raping and pillaging. And the real point of the thread would be long gone with all the hear-say that was introduced.
So, keep in mind, things are not always what they seem and like all public forums, you need to take it (any information) all with a grain of salt. Otherwise you will be taken in by all the BS! In the end, the real story usually comes out!
RKT:
In what way did this "prototype 858 kit" differ from the 858 Kit that you are offering to the General Public? Chad mentions its a prototype and one off kit, could you please expand on this?
In what way did this "prototype 858 kit" differ from the 858 Kit that you are offering to the General Public? Chad mentions its a prototype and one off kit, could you please expand on this?
Kelsey, maybe to help clear the air you can comment on what you found to have gone wrong with this particular install? was it an install/tune failure or was this particular kit set up slightly different by you to test something, or maybe setup to what you have working at higher elevations and at these lower elevations it needs a slight tweek to work?..I am looking to do a kit on mine and want to see everybodies stuff..good,bad, and ugly before I decide what to buy...
R
RKT
Well-known member
So, AK, you are condsidering an 858 kit??
While, by your own admission, you are not considering this kit.. (I have no problem with that) I will still answer your question. But, please induldge me by answering a few of mine first...since you are apparently engine savvy, sound fair?
1) By the looks of those cylinder pics posted, do you see any aluminum transfer?
2) Any signs of massive engine failure?
3) Thoughts, based on the cylinders pics, of what happened?
4) Still looking to find out where the "mis informed" part came from.. WHO was informing WHO that the AK 858 kit was still running? You got any intel on this? Because I KNOW nobody at my shop was talking to anybody except beamslayer (please chime in if you wish) about the AK 858 kit.
I will tell you that OUR 858 complete sled (sold over a month ago)with now over 1000 miles on the 858 kit is still running and running well..And was put through torturous testing while in our possession (all season)
I look forward to your answers and will promptly respond..
Ean..Feel free to call me on Monday if you want to discuss anything about the 858...Always a pleasure to talk with you.. I refuse to get dragged into ANY sort of thread decline and public forum BS.. (please see my earlier post) but have no problem engageing in civil and RELEVANT discussion.
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I am considering all kits out there kelsey, but I do admit the long rod kits have my attention...but carls 900 kit is the same as yours(stock rod) and that one interest me as well....as for what I see..yes I noticed no aluminum transfer..which means it wasnt a tight seize...makes me think maybe a thou tight on bore clearence, and possible that the ring end gaps were tight and touched...but chad said nothing about it breaking a ring either..as for my knowledge of it..chad can verify, I knew chad had installed it, knew he lost a rod bearing right afterwards..other then that, I knew nothing about it until it was posted up here..I too thought it was still on the snow running....As for me buying your kit..or anyones kit for that matter..it will take proof that they have the skirt loading issue figured out, that the motor is reliable, will perform as a 4 grand plus upgrade should and that they will stand behind thier product.., that it will work at my elevations, and at least comes with a complete list of everything in the kit and everything that will still be needed to make it work......thats fair isnt it?I am still waiting to see vids from all the BB kit makers showing their sled on the hill against both stock sleds(and I mean bone stock good running sleds) , pump gas turbo sleds, and other BB sleds...or trust worthy peeps that I know have a clue and will give an honest opinion of a sled they have rode..such as Eric(mountain Horse) or scott(Scott)...
IMHO AK you will be waiting a long time.
Who the hell cares what Polaris thinks or feels.
R
RKT
Well-known member
fair enough... First of all my kit is nowhere near 4K or even 3K...(just wanted to clear that up) we are known for putting out solid and powerful and reliable big bores.. Our history supports that.
I really should have taken video of our 858 against a stocker because it was a slaughter... my bad on that one.. but ours was "suddenly" sold so I do not have it anymore and the set up is much different on the sled by its new owner so there is no comparision to be had anymore.. shoulda coulda .. didn't... But those in this area who rode and witnessed the 858 in action are firm believers. but, again, a video would have been wise..
As for the side loading issue... I would like to ask you WHY you think there is a side loading or rod/ratio problem? what would lead you to this conclusion?
Ok., to answer your questions (as promised)
1) For there being no aluminum transfer on the cylinder.. how massive was this failure?? (Usually with MASSIVE failures, there is aluminum transfer)
Somebody stated how horrible the engine looked , yet, the cylinders show no signs of scoring.. this is interesting to me and surely to you as well? I do have some pics of the pistons though and they show lower shirt scoring front to back. BUT, the rings appear to be free and no aluminum transfer over them..
Short answer.. I do not know what happened BECAUSE I have not seen the cylinders or pistons.. How's that?? So, like everybody else on here... If I were to comment it would just be 100% speculation and guess at this point since I have not seen the parts in question..
I do have an idea of what happened but , I do not speculate (especially on public forums)
So, if and when the parts arrive at my shop, I will have a much better understanding of what may have happened.. Again, I have an idea...
I have tried for days to get in contact with Chad, but he has not, yet, returned any of my calls or emails (very odd, because I have never had any problems with contacting him before and he was always really good about talking to me and information exchange on the 858 testing... Nice guy to work with)..
Hopefully, he gets a hold of me soon..
So, there you have it... the cylinders show no signs of massive failure nor do the pistons (simply because the rings are free) and I have not seen the parts.
So, no prognosisis can be formed..
So, all this "speculation" that is prevalent in this thread is simply that...
It strikes me funny that the BONE STOCK engine can go down frequently and not much is said, but a new BB kit has an issue (yet to be determined) and it is big news!!
Kinda funny if you think about it!Kelsey
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