M8 needs advice.

DustNU · Feb 5, 2013

I have an '07 M8. The last time out it started to develop a low end bog. When I would hit the throttle some times it would about throw me over the bars. If I let off it would usually take right back off just fine and run great. As the day went on it seemed to get worse. My first thoughts were maybe TSS switch but at certain times if I held the throttle in the right place it would continue to bogg or run like Blaaaaaw for as long as I held it in that position. I thought if it was a TSS switch it would die. I never could get it to die. I have also noticed this season after coming down a long steep hill it seems to load up a little. Could it be a broken reed maybe. It seems to idle fine. Deflection, rollers and clutches seem good. Thanks for any input.

m8magicandmystery · Feb 5, 2013

spark plugs..??

fasta76 · Feb 6, 2013

Fuel Pressure??

DustNU · Feb 8, 2013

Installed new plugs(old plugs looked a little rough had a lot of carbon build up on the) throttle cable is adjusted right. Fuel pressure is at 47.4 PSI lets hope it's just needed new spark plugs. Any other suggestions?

m7john · Feb 8, 2013

I would think clutching.

mbcat · Feb 8, 2013

Sticking apv, chipped reeds or belt ware-deflection. Could also be cracked spider weight shifted over or pooched spring. Check for sticky power valves first!

DustNU · Feb 10, 2013

Sled ran great!! It had a slight bogg two or three times at the beginning of the day but that was it. Rode in about 2 feet of new powder and it didn't big the rest of the day. Must of been the new plugs or maybe moving the tube on the ECU that helped. Thanks for all of your help and input!!

DustNU · Feb 24, 2013

Well bogg is still there and seems like it is getting worse. While going down the trail on the way back I could almost make it bogg every time.
If I let off the throttle for a sec then pin it it will bogg. Rpms are between 3800 and 4100. When it Boggs I can hold the throttle in one place and it will just sit there and bogg for 2-10 seconds. If I let off and then pin it again it takes right off and runs great. I have changed plugs. Checked fuel pressure(47 psi), checked clutches, belt, checked power valve adjustments (35mm) did find slight fray in cable where clip on servo had rubbed it. Both valves seem to open and close just fine. Tail light seems to be working fine even when the bogg occurs. Any other suggestions? Thanks!!

RobertTrivanovic · Feb 24, 2013

DustNU said:
Well bogg is still there and seems like it is getting worse. While going down the trail on the way back I could almost make it bogg every time.
If I let off the throttle for a sec then pin it it will bogg. Rpms are between 3800 and 4100. When it Boggs I can hold the throttle in one place and it will just sit there and bogg for 2-10 seconds. If I let off and then pin it again it takes right off and runs great. I have changed plugs. Checked fuel pressure(47 psi), checked clutches, belt, checked power valve adjustments (35mm) did find slight fray in cable where clip on servo had rubbed it. Both valves seem to open and close just fine. Tail light seems to be working fine even when the bogg occurs. Any other suggestions? Thanks!!

So you made sure the belt wasnt sitting to low in the secondary due to ware? And you cleaned the powervales? Just cause they open fine doesnt mean they wont stick. The taillight working or not has nothing to do with it, if there was a short in your taillight it would likly blow the fuse up front, and possibly go into limp mode, I dont think thats your issue. Is the sled modded? If so what mods. Are you running a fuel control box? If so you could be running to rich and that RPM and the fuel builds up and causes a bog. Is the snow deep? Or even just fine? You could be sucking snow in your intake. You say you checked your clutches what did you check? Make sure your springs are still in spec? There not actualy cracked or broke up front. Weights arent sticking? How long have you rode your clutch? Even if you adjust it as it wears it could still cause an issue if its really warn out.

RobertTrivanovic · Feb 24, 2013

Has the max RPM your reaching changed? If so how much?

m8magicandmystery · Feb 24, 2013

check for wiring issues that may be happening on the harness strapped on your fuel rail

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M8 needs advice.

DustNU

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m8magicandmystery

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fasta76

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DustNU

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m7john

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mbcat

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DustNU

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DustNU

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RobertTrivanovic

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RobertTrivanovic

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m8magicandmystery

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