RK TEk 858 big bore problems, need help.

[rockhead00]

installed the 858 rev 2 big bore on my 2013 pro rmk.

first ride out hit DET 7 code, shut off sled and restarted. ran ok but kept cutting out around the 7700 to 7900 rpm mark and would drop down to 6900 rpm. also could only pull around 7900 rpm with clutching set up recommended to me.

Asked RK tek and was told i just have to figure it out. adjusted clutch set up and went out second time and reached 8100 rpm consistently but still had problems at the 7700 to 7900 rpm. checked plugs and found exhaust side had a bit of carbon build up so changed the plugs

third time out, adjusted clutching again and hit 8300 on some pulls but still cut out around that 7700 to 7900 rpm when i would get into that range. checked plugs again and they looked a lot better, exhaust still had what looked like a bit of oil on it but clutch side looked perfect

sled would not stay idling when started up and would have to hold throttle a bit until it warmed up and then would stay idling for a bit. took sled in to have idle checked out and bore scope and compression test to make sure the DET 7 code and cutting out didn't do any damage. they said my TPS was only at 4 watts so they zero'd it and reset it to recommended 9 watts so that also might help with some of the issues i've been having with the cutting 7700 to 7900 rpm. Bore scope looked ok and compression was 120 and 130.

Sled still idled rough and went out for 1st ride after TPS adjustment made it about a km and sled died, shut it off and restarted got another km and self died and would not restart. checked plugs and they looked a bit white/lean so towed sled back to truck and stopped in at sled shop in golden and bore scope show scuffing on cylinders.

Talked to boon docker today and he said that adjustment of the TPS should not affect the mapping of the control box.

So i'm scratching my head and don't know what to do??? could i really of toasted my cylinders in 2 kms on the trail heading in? wasn't holding it full throttle or anything..

leaning towards just putting it back to stock.

any suggestions or experience with this?

Cheers.

 

[mountainhorse]

I would really contact Jeremy Kinzer on the forums here... He really has these 858's at your altitudes.






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[escape6875]

RK TEk 858 big bore problems

I was thinking of buying one of these kits this week.
Sorry to hear about your misfortune, hope you figure this out.
Out of curiosity...
What domes do you have?
What elevation are they for?
What elevation were you at when is it stuck?
What was the temp out?

 

[rockhead00]

I was thinking of buying one of these kits this week.
Sorry to hear about your misfortune, hope you figure this out.
Out of curiosity...
What domes do you have?
What elevation are they for?
What elevation were you at when is it stuck?
What was the temp out?

domes 13.5
elevation 5000 plus
any elevation it seems to cut out
-5 degrees celsius to -10

 

[RHODESIE]

boonie

when you fire up and the fuel box first comes on what software does it have in it, 132a or 133c?

 

[rockhead00]

when you fire up and the fuel box first comes on what software does it have in it, 132a or 133c?

I would tell you if the sled would fire up lol.. I will check tomorrow with the battery connector and let you know.

What difference does the software make?

Thanks

 

[escape6875]

RK TEk 858 big bore problems

The cutting out is fairly isolated (7700-7900) sounds like a fuel setting.
As for the seize were you at the low end of your elevation and temp?

 

[rockhead00]

The cutting out is fairly isolated (7700-7900) sounds like a fuel setting.
As for the seize were you at the low end of your elevation and temp?

just starting in at about 3500 feet and temp was around 115 degrees to start and when it started to sit down second time i think the temp was at 135.

Motor would still turn over when pulling but seemed like there was no compression, i thought it was a electrical connection at first.

 

[RHODESIE]

I would tell you if the sled would fire up lol.. I will check tomorrow with the battery connector and let you know.

What difference does the software make?

Thanks

I would just like to know. the big bore itself should not be causing any issues. all it cares about is fuel, air and spark. remove the fuel box and plug the injectors back in like factory and see if it will light. don't ride it like that but it won't hurt to see if it will fire up.

 

[rockhead00]

I would just like to know. the big bore itself should not be causing any issues. all it cares about is fuel, air and spark. remove the fuel box and plug the injectors back in like factory and see if it will light. don't ride it like that but it won't hurt to see if it will fire up.

ok i'l give it a shot and let you know

thanks

 

[m8magicandmystery]

Talked to boon docker today and he said that adjustment of the TPS should not affect the mapping of the control box.

Cheers.

I don't understand this..^^

don't you identify the min and max tps then divide the difference by 6 and then that value you add to the minimum and then add that value again to the new total on the first step and repeat six times and that's your tps setting for your box if your not on the duty cycle option.

so in my mind if you change your tps your values you programmed in the box will not be accurate.

Is there any chance your box is set on duty cycle and not tps setting ??

Is your acceleration mode activated and set right or is it not activated..??..

im just going by my new boondocker box for my CAT..so if the info I give here is not relevant in any way ..my apologies...but I thought they operate similar between the two brands..

 

[rockhead00]

I don't understand this..^^

don't you identify the min and max tps then divide the difference by 6 and then that value you add to the minimum and then add that value again to the new total on the first step and repeat six times and that's your tps setting for your box if your not on the duty cycle option.

so in my mind if you change your tps your values you programmed in the box will not be accurate.

Is there any chance your box is set on duty cycle and not tps setting ??

Is your acceleration mode activated and set right or is it not activated..??..

im just going by my new boondocker box for my CAT..so if the info I give here is not relevant in any way ..my apologies...but I thought they operate similar between the two brands..

my problem is i don't know anything about the function of the control box in relation to stock ECU, and i was wondering after my sled died if the adjustment to the TPS did something to the mapping. from what boondocker explained to me was the TPS adjustment is not made on the control box but made through stock ECU on the polaris.

my other question is if the TPS was only reading 4 watts is that because of the control box. do they make the TPS adjustment while the sled is off or running? maybe it would of read normal if sled was running and control box was on?

any ideas?

 

[gmustangt]

What are you running for fuel?

 

[rockhead00]

What are you running for fuel?

AV gas

 

[rmscustom]

No need for AV gas with them heads at 5000'+.

 

[m8magicandmystery]

my problem is i don't know anything about the function of the control box in relation to stock ECU, and i was wondering after my sled died if the adjustment to the TPS did something to the mapping. from what boondocker explained to me was the TPS adjustment is not made on the control box but made through stock ECU on the polaris.

my other question is if the TPS was only reading 4 watts is that because of the control box. do they make the TPS adjustment while the sled is off or running? maybe it would of read normal if sled was running and control box was on?

any ideas?

on the old boxes a wire had to be run from the tps to the box so the box could get a tps reading..on the new boxes that DO NOT have the injector plugs but plug into the ECU the box reads the tps variations without the need to run the extra wire...In my case to originally set boondocker direction say to put sled on stand with the box in the tps reading and read the tps at idle and at wot for 3-5 seconds...my low was 56 and the high was 166..then the difference between the two was divided by 6 = 18.33...So next step was to go into the controller tps setting..set the first at 56...second at 74 third at 92 forth at 108
fifth at 126 and the sixth at 142..

These settings are what determine your load demands in each of your different rpm settings in each rpm range...(13 on the new box)..

so if you changed your tps on your sled it has to affect your controller in my opinion.

Are you sure boondocker did not say "that the TPS READINGS are sent to the controller through the ECU"...not adjustment

The control box will not adjust tps readings..it reads the tps readings to have your control box respond to the tps readings through the setting described above,

so if you play with your tps on your sled it will throw the six reading setting out because your low and high tps would have changed.

that's my take on it..

 

[rmscustom]

I would think M8magic is right. BD box on a 13 pro works the same as he described.

 

[m8magicandmystery]

.

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Talked to boon docker today and he said that adjustment of the TPS should not affect the mapping of the control box.



Cheers.

you know..i think what they were saying is that if you adjusted your tps it would not affect the mapping of the control box....BUT they are expecting that you would for sure still do the high /low reading and six adjustments after the change which in effect is not affecting the mapping because you still retain the ability to do the mapping...whoa what a mouthful..but I hope you get what I mean...but once mapped and then if tps is changed then your tps map is not right...your rpm map won't change but the tps definitely did..

Your fuel map in the controller changes the ECU duty cycle...but the tps info in the controller is only READING the ecu

 

[Newby2sleds]

.....they said my TPS was only at 4 watts so they zero'd it and reset it to recommended 9 watts so that also might help with some of the issues i've been having with the cutting 7700 to 7900 rpm. Bore scope looked ok and compression was 120 and 130.

Sled still idled rough and went out for 1st ride after TPS adjustment made

The TPS is adjusted by volts. what do yo mean by 4 watts?

The TPS needs to have the base setting done either at the dealer ship or with a good multimeter. After that is done then you set up the Load points in the boondocker box like M8magic.. says

 

[everytime5.9]

What method did you use to break it in? Any heat cycling etc?
Was the scuffing located towards exhaust/intake or all over?
Just running RKT's numbers? Did you have any gauges?

We had an 858 that would foul a plug every ride from excessive blow by. Had intake side scoring that made the pistons sloppy and they started rocking in the cylinder causing the dreaded crack (Cylinders were probably already hurt 2011 Pro). Less than 100 miles. Putting this one back to stock for the rest of the season because the 858 pistons were back ordered until mid April.

Post some pics of the damage when you get the chance.