Silber Pro running on only 1 cylinder..HELP

TurboMatt · Jan 5, 2012

We are out in Cooke City riding. Sled has run good for 3 days straight now. Ran good most of the day today, towards the end of the day my buddy took the sled for a rip, ran fine, I fired it back up to head in: now the sled is only running on 1 cylinder. Couple strange things: when I 1st started it up after my buddy rode it there was a wierd metal rattling sound and wasn't running right.(there was a chunk of stick in the by the primary clutch, I thought this was the issue, but wasn't) I shut it down and started it up and the rattling went away eventually, but its only running on 1 cyl. We changed the plugs, no change. We towed the sled in.
what we have done:
-We have tested spark, it has good spark on both cylinders. The MAG side isn't running though. We pulled plug wires to test, the sled runs when we pull the mag side(terrible still obviously), when we pull the PTO side the sled won't start. that's how we came to the conclusion the mag side isn't running. The MAG side piston is also wet like its not running.
We did a compression test, both cylinders are at exactly 90psi,that seems low, but we are also sitting at 7600ft elevation too. But they are both the same.
-We looked at the pistons and rings through the spark plug hole and VES openings and they look normal.
-The sled barely runs, it doesn't clear out if I try revving it up. It won't rev over 5500rpms.
No check engine light.
Sorry for the long post.
Any ideas?

Boston Racing · Jan 5, 2012

What lights are displayed on the control box?

tyler@aerocharger · Jan 5, 2012

check you box lights

You can check you fuel box when you first start it up. if you have green and blue lights on at the same time at idle the box is sensing boost to soon and adding fuel, causeing a rich condition.

mt.sledder · Jan 5, 2012

when it's running at an idle does the green and blue light both come on at the same time? Sounds like it's running real rich and maybe loaded up to the point the one side won't fire. Try lowering the green setting down to 1 or 2 just to see if it will start firing on both cylinders. Do not drive it unless you bump the green back up to normal.

dmkhnr · Jan 5, 2012

Check the reeds.

yamazoom · Jan 5, 2012

For what it's worth, my 2012 makes 115 PSI at 5,000 feet. It could just be the gauge your using. Good luck and keep us posted.

Liv4snow · Jan 5, 2012

Sounds like you might have a bad control box. Mine did the same thing last week. I dont think these dobeck boxes like water very much at all we are going to start putting ours in a pelican case.

Liv4snow · Jan 5, 2012

We also are going to set ours up with deutsh connectors so we can unplug the and change them easily.

MrMagoo · Jan 5, 2012

Matt I'm in Cooke now too staying at elkhorn. Mine is sort of doing the same thing. At idle though I have the green blue light on and can't find what's making it.... Pm me maybe we can trouble shoot them both??

EZmoney · Jan 5, 2012

MrMagoo said:
Matt I'm in Cooke now too staying at elkhorn. Mine is sort of doing the same thing. At idle though I have the green blue light on and can't find what's making it.... Pm me maybe we can trouble shoot them both??

You box may be damp try drying it out with a heater of some sort. I had the faint blue light on after a ride when i got it home after heavy rain and being on the deck. I put a heater on it through out the night and it was gone in the am. since then i siliconed the box and use a pelican case. Although i should add when i started the sled when the blue light was on on the far right before i dried it the sled idled fine.

brycter · Jan 5, 2012

almost sounds like the woodruff key broke on the stator. and now the timing is off. that is the sound of metal bouncing around.

since 2008 most of the new sleds show 90 - 110 cranking compression. engine needs to be cc'd to do corrcet math. The manual doen't even show a cranking compression number any more.

i would unhook the box and see if you can get it to run stock.

Sunvang · Jan 6, 2012

Same problem I had? http://www.snowestonline.com/forum/showthread.php?t=292976

Sled was running rich, lowered green then it would start fine.

Try taking the MAG spark plug out, tun ignition off, pull a couple times to empty the cylinder, reinsert new plug and try again.

TurboMatt · Jan 6, 2012

Upon further inspection I think the motor is toast. I found 5-6 1/4" chunks of cast aluminum(thats just what I found on a quick inspection) along with a bunch of tiny chunks as well in the belly pan.
I can't see any holes, but I also can't see the bottom side of the motor decent. I think its safe to assume the chucks came from the bottom of the motor?
Piston skirt broke off maybe?
God damn, that thing was running so good too. Good a/f's, 50/50 race/premium mix for gas, only running 8-9psi and I was completely happy with the power it was putting out. I even had my oiler turned up to try to prevent this kind of failure, I hand calculated it was at 40:1. Motor has about 1100 miles on it.

I'll keep everone informed of my findings when I get home and get to tear into it.

2XM3 · Jan 6, 2012

ah crap....feel your pain, its either piston skirt or more that likely the damn cyliner skirt broken off...this is the first one in a pro i've heard of, very interested to see what you have found !! Kind of hoping its a busted piston and not the skirt problem surfacing in the pro motors. :face-icon-small-sad

Could also be the pto bearing takin acrap and a hole in ur case...

POLZIN · Jan 6, 2012

sorry to read that ! THAT SUCKS! how many miles where boosted?

stocksucks!! · Jan 6, 2012

my sled did the same thing this week.. ran strong all day then around 3:00pm one cylinder.. checked plugs found pto side loose.. took it out cleanded it off and reinstalled.. ran ok after that but not the same as ealier in the day. then 15 min later real boggy and at full throttle i was 14.5 on the af so back to the box start bumping up some fuel and would not go away.. so re set back to default and same thing but not i am on one cylinder again. take both plugs out clean out the holes and re install.. sled runs good my thoughts now is i wish it was stock. but as i am headed out i get into 4-5 psi boost and boogy. again. so stay off boost and limp her out well that was only good for a bit then 1 cylinder again.. 1/8th of the way down the trail plull plugs clean out holes re install runs fricken sweet all the way to the truck even boosted.. any ideas cause 3 hr drive to the mountains for a test and tune sucks. oh ya i have the iridum plugs silber said to use and i am running 7 psi with 102 octane fuel.. make matters worse my buddy turboed his the same time same sled same milage same fuel same clutching and his was awesome all day. it seemed like my control box didnt do any thing when i adjusted it.. as far as a/f goes. and no green blue at idle please help.

stocksucks!! · Jan 6, 2012

i forgot why at idle do my a/f show 20-22 at 1500-1600 rpm a little burp of the throttle it bogs but then idles at 2000-2350 and af at 15??

MotoXTurbo9 · Jan 6, 2012

If you can verify the broken bottom of the case, check your reeds or look for anything foreign object related..

TurboMatt · Jan 6, 2012

dannyc1225 said:
If you can verify the broken bottom of the case, check your reeds or look for anything foreign object related..

I'll check everything when I get home and report back

POLZINHUNTER said:
sorry to read that ! THAT SUCKS! how many miles where boosted?

about 200

gmustangt · Jan 6, 2012

stocksucks!! said:
i forgot why at idle do my a/f show 20-22 at 1500-1600 rpm a little burp of the throttle it bogs but then idles at 2000-2350 and af at 15??

I assume this happens after u stop for a break, it's hot air in the pipe... Assign as u move the sled it goes back to normal.

Silber Pro running on only 1 cylinder..HELP

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