RK Tek 858 Big Bore Kit

[polarisblue]

858 rkt

Im still having problems with my 14 858 , on long pulls at 8000-8200 the motor acts like its taking timing but no det light. It will go from 8000-8200 down to 6600 (wide open throttle) but no light? On the bottom end it pulls like a freight train. I have 91 mixed with 112 race gas. If I hold it long enough through its (little fit) it will go back up to 8000 again.If I let off instantly it seems fine right back up to 8000 again .I have checked the TPS and its spot on. I am running a pcv not a boondocker so I have been pretty much on my own.I am at 1800ft , I have made many different maps and still no luck. I have heavy weights and a big helix to lug it down like Kelsey says ,so I don't think that's the problem. If anyone has a map for a pcv let me know . This is driving me crazy!!!

 

[RusseauRestore]

Hello Polaris Blue

That is basically the same thing mine is doing.

I have worked a Power Commander and now a Boon Docker as that is what Kelsey said to run...I am also working with another member of Snow West (Powerage) and he has been helping me a great deal with Map's and clutching etc. Look for a post called "RKT 858 Fuel Numbers"

If I find out anything that works...I will let you know.

-Scott

 

[geo]

Coolant temp #'s??

 

[lucasMX358]

Prolly not the case here, but my boondocker did the same thing. the capture button was stuck in nitrous mode and was adding crazy fuel at 5000 rpm. Hope this helps.

 

[wellfed777]

polarisblue
hows your clutching ? just wondering if its strugling to back shift ?

 

[polarisblue]

858 rkt

The engine temps are 125 - 131 all day long. When my sled goes into its little fit it is on top end , definitly motor. I am going on the dyno this week to build a map to find out what is going on. I also have two pipes to try plus the stock one.

 

[danby]

Polarisblue I have seen this on 2 other sleds both are pro rmk 800's it progressively gets worse. It turned out to be the exhaust sensor. This was on stock sleds but sounds the exact same

 

[geo]

That will be very interesting data. Please include it all and thanx ahead of time.

 

[polarisblue]

858 rkt

Danby did it throw any code or det light?

 

[danby]

For the first little while it did not then the check engine light started to come on as it started to cut out more often. We checked the exhaust sensor with a bolt meter and it was showing open . Changed the sensor with one from another sled and cleared the problem right up

 

[polarisblue]

858 rkt

I think I finally got this sled figured out! Jkinzer at SPS has been really helpful, he really knows how to clutch these 858s, the maping is still a work in progress but Im headed in the right direction. The sled pulls 8250-8300 with no det issues. Kelsey and Jkinzer both are right these motors like to be loaded hard. THANKS FOR THE HELP!!!

 

[Vi-PEC Powersports]

Hello Polaris Blue

That is basically the same thing mine is doing.

I have worked a Power Commander and now a Boon Docker as that is what Kelsey said to run...I am also working with another member of Snow West (Powerage) and he has been helping me a great deal with Map's and clutching etc. Look for a post called "RKT 858 Fuel Numbers"

If I find out anything that works...I will let you know.

-Scott

Wee can definately help you all guys, Pm us if interested.

Vi-pec Powersports

 

[Jkinzer]

as Kelly stated almost every one of these that hasn't been running right have been clutching not so much fueling, every one i've talked so far as needed more primary weight especially in the heel and a few ended up with full helix,springs and rooster weight clutch kits. if yours isn't running right add more primary weight, you will be amazed

 

[brycter]

We have a couple vipecs 858 on the snow. They are working very well. I can tell you it is not all clutching. You need to be able to adjust timing and fuel through some trim tables. This will get you spot on.

Give us a call. Sooner or later the capabilities of a stand alone will not be over looked.

 

[polarisblue]

858 rkt

Had a great weekend on the 858 . The motor pulls very hard from start to stop. It revs 8300-8350 with 78 grams of weight Im waiting for some tungsten washers to add more weight to the heel. Jkinzer is right on track with loading these motors, I would like to think I could get away with 80 grams. I have also made a pcv map that works very well, it has been a rough road but with lots trial and error I have a map that works at sea level. Kelsey builds a great product, the 858 is a different animal!!!

 

[rmscustom]

Vi-pec,
What weights or clutching are your non bandaid motors pulling? Or maybe a side by side comparison would help to justify the $1600+ upgrade...

 

[3beans]

The reason a standalone is overlooked is the outrageous price! Having to spend $2k on a programmer is hard to swallow when the builder doesn't recommend it with the kit.

 

[Lookin for info]

Wrong page!