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M8 Low End Bog

B
Jan 15, 2008
121
18
18
Covington, WA
I have a stock 2009 M8 SP. Only mod has been 2 Cool vents and secondary slick shift bearing. It has a relatively slight bog right off of idle- nearly all the time. Doesn't seem to matter in deep or not. Check the plugs, they are fiercely carboned up. Had it in to the dealer before the last two rides of last season. They turned down the oil pump verrry slightly for fear of chocking off too much oil. Still have the bog and still have the massive carbon issue to the plugs. Has anyone else had this issue? What did ya do about it. I am not going through this again this season if I can help it.

Thanks for a reply.
 

Griff

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Nov 26, 2007
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Have you checked belt deflection & proper clutch calibration to eliminate those as possible causes?
 

RickM

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May 25, 2006
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Central Wyoming
Bently

I have the same sled, I had to turn down the oil pump, after each days ride i would refill and measure the oil ratio, this took me about a half dozen times checking and rechecking, then i started to lengthen the rod out. I was as 24 to 1 ratio, now at 45 to 1 ratio, plugs are great, and engine is lots crisper.
and ive loged over 1000 miles and no problems. When new it was pig rich on oil. hope this helps you. You can remove the rod from the top, not too hard,
if you need more help let me know.
 

backcountryislife

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Nov 26, 2007
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Have you checked belt deflection & proper clutch calibration to eliminate those as possible causes?

THat would be my first guess.

EVERY stock M8 I've seen is heavily carboned & the high oil ratio is the norm, not the other way around.

With the non linear way the oiler works I would be WAY sketched out about a 45-1 ratio with that sled. Oil makes power, most don't understand this, but testing shows it to be true (and I don't mean on a computer or in a book)
None of the big boys I ride with run more than 32-1, most run higher (we're on premix) I won't trust that mechanical non-linear oiler do do what I want it to on my sled.
 

WyoBoy1000

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Nov 27, 2007
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Red Lodge MT to North, CO
45:1 with the oiler sticking and you could be running lean. If its a 09 the oiler will stick, I deleted mine and you can feel it stick when holding the oiler in your hand. In the 09 sleds they changed the oiler to oil the engine when in reverse and caused a problem. after the delete I run 40:1 premix and the sled runs crisp has seems to have tons of torque. also could be belt deflection
 

montanasledder

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Dec 19, 2001
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I got the delete for mine and still undecided if im gonna do it or not. Still got the jitters about all the bad stuff ya hear.
 
B
Jan 15, 2008
121
18
18
Covington, WA
Belt deflection is right on- and I am also aware that oil increases HP contrary to what most might think. This muther goes through an a**load of oil, so I think I will try RickM's suggestion to do a ride and return to the shed to figure out my overall oil ratio used. Thanks for all the advice, I appreciate it. Hope you guys have a great winter. Watch for Avys!
 

skidooboy

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Nov 26, 2007
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central lower michigan
has anyone added an extra return spring to get the oil pump to close all the way each time the throttle is closed?

would be great for someone to do a pictorial write up on how to adjust the pump, or add an extra wrap to the oil pump return spring.

rickm seems to be the man in the know about this. i just bought 2 09 m8 153 (first cats) want to try to get the jump on a few of the "quirks".

ski
 
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