858 big bore dropping a cylinder?

[kooter353]

Thanks. Much appreciated.

 

[shop quad]

I have my 858 put back together with about 20 miles on it. 3/4 throttle and it does the same thing, cuts out, let off and hit it again, cuts out. I can't even slowly take it up to wide open. There must be a fix as there are quite a few sleds that are doing this. 2014 pro, 12.5 domes, 858, boondocker box, 1200' elevation, 50/50 av gas and premium. Previous owner said it ran great up on revy

 

[cnelson6]

Found this on snowest for your elevation.


Here is my fuel numbers running 91 NON ETH pump gas at 1200FT. I have 9 grams heel 5.6 mid and 3.5 tip on rooster weights. Total weight of 74.1 grams. Running a 150-340 (bright green) primary spring. Secondary is Team tied with a 140-200 spring (red/blue) and a 73-61 .46 helix. Gearing is at 19 top and 45 bottom. This setup is working very very good. I am hitting the rev limit every once in a while. I think i am going to add .5 gram more to the tip and see how it works. Snow is very light and it's cold here. Warm day in heavy snow i don't think it would need the extra weight. Hope this helps some of the lower elevation guys out.

EDIT** Clutches are very very cool with this setup also.


2500: 00 00 00 00 00 00
4000: 02 02 02 03 03 03
5000: 03 03 03 04 04 04
5500: 04 04 04 05 05 06
6000: 07 07 08 09 09 09
6500: 08 08 10 11 11 11
6750: 08 08 10 11 11 11
7000: 10 12 12 13 14 14
7250: 09 11 12 15 15 15
7500: 09 11 12 16 16 16
7750: 08 10 11 17 17 17
8000: 10 12 12 18 18 18
8500: 11 13 14 18 18 18




Sent from my iPhone using Tapatalk

 

[cnelson6]

Here's his updated info.

Did 120 miles yesterday and tuned most of the way. It is running very very good at these #'s. Rode 800-1500 feet. Below 1000 i was still hitting rev limiter with 74 grams in. Even a couple times above 1000. Gonna try add some more weight yet i guess. The more i drive this engine the more power it seems to make!! I still think these numbers are a little rich on the top end. Next ride i am going to pull a couple more numbers out from 7500 and up. Right now it's running 11.4-11.7 AFR above 7500. The rev limiter needs to be disabled with this engine below 2500 ft i think. It just revs so fast and high that it trips it a lot unless the engine is very loaded. A couple minor inssues that never really bothered me during the 120 mile ride yesterday. About 300 miles on it now.


2500: 00 00 00 00 00 00
4000: 03 03 03 03 03 03
5000: 04 04 04 04 04 04
5500: 04 04 04 04 04 04
6000: 10 10 10 10 10 10
6500: 10 10 10 11 11 11
6750: 08 08 10 13 13 13
7000: 10 12 12 13 13 14
7250: 09 11 12 13 14 14
7500: 09 11 12 14 14 14
7750: 08 10 11 13 13 13
8000: 10 12 12 16 15 15
8500: 11 13 14 17 17 17


Sent from my iPhone using Tapatalk

 

[Timber_12]

Any update? Get it fixed? I have a Carl's cycle doing the same thing but we don't have any snow to even try to figure it out now.

 

[shop quad]

Well my testing ended with a total loss of the sled, burnt to the ground. Had a couple burp/backfires and poof, burst into flames.

 

[snowcannon]

Well my testing ended with a total loss of the sled, burnt to the ground. Had a couple burp/backfires and poof, burst into flames.

I hope you've got insurance?

 

[shop quad]

Got insurance, just hope they cover the accessories that were on it

 

[shop quad]

So did anyone find a solution? I can't help with testing as my sled is gone. I would like to know a fix so if it happens in the future with my sled or others I could lend a hand to make things run.

 

[knocksum]

Too much secondary spring and helix. You are slipping in the primary at full throttle hitting the rev limiter. Lets see some pictures of your primary clutch faces.