M8 low rpm studder

zeke

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Looking for some help with a 2011 m8. Sputters pops and farts on low rpm. Give it a couple burps and away it goes. Pulls hard and runs good wfo. After a climb on the way down it loads up and you have to burp it to clean out again. Changed plugs is about all we could do on the hill. Plugged the plug holes and had decent comp.
It will idle.

thanks
 

mountianguy

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Looking for some help with a 2011 m8. Sputters pops and farts on low rpm. Give it a couple burps and away it goes. Pulls hard and runs good wfo. After a climb on the way down it loads up and you have to burp it to clean out again. Changed plugs is about all we could do on the hill. Plugged the plug holes and had decent comp.
It will idle.

This is a common problem with those engines. Mine does the same thing, it is over fueling. I have uped my idle speed a little, 1800-2000 it helps but is not a cure. Reeds may help also but wont cure it. It is something I have learned to live with. What is happening is when you back off at the end of your climb the case is still loaded with fuel and the requirements are way less at an idle. The engine stills sends the remaining fuel up the transfer ports and you get the blubber when descending. A fuel controller may help but for $500.00 its an expensive experiment. These HO engines do have a history of failing reed valves, you may have a damaged or broken reed. The only way to tell is remove and inspect. Hope this helps good luck.
 
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