08 860R Popping Plugs

Ekim

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I have recently installed a 860R BB from SHR and have popped a couple of plugs. Everything seems fine, when running, but it blows plugs and starts running rough. I change plugs and away she goes. Am I running too much oil for break in or ??? Any info appreciated.
 

boots

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It is just his kit mine does the same thing. You got ripped off buy his kit. And he won't stand behind his product or help you out.


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oler1234

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What we found was that it was more of a compression thing and gas. When just on the edge the deto sensor just wouldn't catch it and the engine would hammer them out. We eventually lost a cylinder not knowing that. Try jetting up 1 size or running higher octane fuel.
 

MtnMaster

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It is just his kit mine does the same thing. You got ripped off buy his kit. And he won't stand behind his product or help you out.


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You might be the first person in the history of S&M or Dootalk to say those words. If Big John isn't standing behind his product, there is an underlying issue that we're not hearing. Everytime I call him with a question or concern he is way more than willing to help out.

As for the plugs, definitely sounds like old fuel or not enough octane for what you're running. A very common mistake or misconception is; Engine builder asks what elevation do you ride at? Customer says "4,500 to 8,000 feet." Engine builder says "ok, you need 14.5:1," or whatever it may be.

Problem is, you unload at 1,500 or maybe 2,000 and ride a 25km trail in to get to that 4,500 feet. I'm not saying that is the issue, but its very common.
 

Ekim

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Thanks for the info guys. I run at 2000' and above. I installed the 13 to 1 comp head. I am running gauranteed 91 octane. Should I be running high than that? I will empty the tank and try 94 octane or mixed 110. Thanks. Still waiting for info from SHR, but I'm sure he will know. Thanks
 

MtnMaster

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Thanks for the info guys. I run at 2000' and above. I installed the 13 to 1 comp head. I am running gauranteed 91 octane. Should I be running high than that? I will empty the tank and try 94 octane or mixed 110. Thanks. Still waiting for info from SHR, but I'm sure he will know. Thanks

Don't email him, actually give him a call. He probably gets a hundred emails a day.
 

slededjr

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You should be fine with 13-1 @2000' and up with pump gas, as long as it's good. I run 13.5-1 no issues. Mine is a Jaws 860 with RK Tek head. Probably bad/old gas. I run the ultra 94 from P-Can this year now that it's available close to me. Ran 91 all last year.
 

Ekim

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What happens when the knock sensor trips? If it is detonation and the knock sensor trips, what happens.
 

slededjr

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first deto, knock sensor will retard timing 2 degrees, knock sensor keeps seeing deto, it will retard it another 2 degrees and engine light will turn on. So i am told anyways. Mine has never deto that bad before. a few guys are experiencing what some call microscopic deto, not enough deto to hear any abnormal noise, or retard timing and turn on engine light, but plugs have loosened off, and some have even seen head bolts loosen.
 
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Ekim

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What about oil pump adjustment? I set the new cable at the same distance as the old cable. Old cable had frayed. When WOT the oil pump cam is just about at the pin stopper. Is this right?
 

oler1234

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a few guys are experiencing what some call microscopic deto, not enough deto to hear any abnormal noise, or retard timing and turn on engine light, but plugs have loosened off, and some have even seen head bolts loosen.

Bingo, I run a 13.5 head with nitrous and run into this problem. But as they say, lowest octane you can run possible with highest compression head will give you optimal results. I had this problem last ride,. Word of advice, when you get to this point you can literally feel it in the bars, feels like the clutch going to come off.
 

Ekim

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Does not feel rough or sound rough. It just starts to bog (kind of) like a fouled plug. Added higher octane gas with less oil in the tank and am trying it again tomorrow.
 

Ekim

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Tried again todaY. Higher Octane and still fouling plugs. Adjusted the idle screw on the side of the carbs in half a turn and will try again. It seems to foul the plugs low in the rpm range. 3500 to 5000 rpm on the trail. Seems to be just the PTO side as well. Has anyone had too much oil and fouled plugs. Is this problem going to get better or worse with higher elevation? I am going riding next at 6000'.
 

pfi572

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What do you have carb needles set at? Check to make sure the hook over top of the needle is holding them down. If the hook isn't holding them down they can rise and cause this.
Something to check.

Tried again todaY. Higher Octane and still fouling plugs. Adjusted the idle screw on the side of the carbs in half a turn and will try again. It seems to foul the plugs low in the rpm range. 3500 to 5000 rpm on the trail. Seems to be just the PTO side as well. Has anyone had too much oil and fouled plugs. Is this problem going to get better or worse with higher elevation? I am going riding next at 6000'.
 

Ekim

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No egt's. This kind of work is guesstimate. I will remove a little oil.
 

rusty

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Needles would not have impact unless they are already shimmed. Mid range is a lean spot to begin with. Have you checked the rave valve to see if they are stuck open.
 
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