M8 Not reaching full RPM's and It's not the clutching!
- Thread starter offroadmatt
- Start date
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Kbakbmr
Active member
I'm having the same problem with my 08 m8, I've put a new spider in my primary, new yellow white spring, new 73g weights. In secondary I have replaced the rollers w/bdx rock rollers, new orange spring shift assist and even put new black plastic washers in the helix at the outside end of the spring. Replaced pv cables cleaned pv's. New plugs/wires So far I've gone from 7500 to 7910 but I can't get over that. I ride from 1-5000ft. When you figure it out let me know!!!!!
Shift assist will lower RPM around 200-300 try removing that! Also check mag side motor mount. That was my problem!
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What helix, check motor mounts.
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orange 1
Member
Suprised nobody has mentioned your exhaust canister!! Seen this several times with m8 and m1000 aftermarket cans, the perforated screen that keeps the packing in place will break and allow the packing to partially block the exhaust can outlet. At first a few hundred rpm lost and after a few more rides then complete exhaust blockage. Simple check remove can and shake... if it has a rattle junk it or if you have a mirror you can peer inside the canister outlet and inspect the inside. Had many people laugh at this but super easy to check and have had friends bring their machines to dealers who go through everything, change CCU's ECM's replaced stators and coils thousands of dollars all for a simple exhaust blockage!
I have checked this. Even though the oem suitcase was still on when the problem started and the aftermarket SLP has only been on 6 rides now. Also when I put the new exhaust on a replaced both the donuts. Had a little oil leak out of the bottom one at first. But has since sealed up nicely.
Working on getting a new secondary. Will report back with findings. Headed riding Friday see if what little I did find will bump me up at all.
Heard a lot about motor mounts. And have looked mine over several times. I'm I missing something. Do they break or tear? Mine are not broken or torn, but does that mean they are good?
Mine engine mounts were ripped and warranty put a whole new pto side plate on. I really don't think the secondary is going to solve your problem. I would try to swap a primary from another m. I don't remember if this was asked, but did you look the spider over good to make sure it was ok. Also do weights look like the rollers have been rolling or sliding? I had a bad roller that was hanging up from the factory.
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killerrf
Well-known member
you can go to a radioshack or place like that and pick a 5v voltage regulator. just use a 9v battery for supply and it regulates 5v output which is all the TPS has from the ecm. then you unplug stock connector and plug the regulated 5 volt wire to the tps and ground wire to ground on tps and then multimeter on output terminal on tps and then you can see voltage changes as you move throttle.
running it with no belt it should rev past that, but I can't say for sure. That leads me to believe its something other than clutching, still could be it but something seems off.
Did it always do this or after mods, if it did it after mods list all mods after the fact.
Did it always do this or after mods, if it did it after mods list all mods after the fact.
to clarify this, i spoke with Jeff at BDX on the phone today, he said they cannot rebuild the 2008 and earlier models, he is out of the bushings.
He can rebuild the 2009 to present models, they remove the bushing, machine the sheeve for true, and balance the unit for about 90.00. he said for about 10-15.00 more he can counter sink the back of the secondary, to accept cap screws to retain the helix v.s the breakomatics cat uses.
mine will be going in soon. Ski
I wouldn't rev that thing anymore without a belt on. Harmonics can and will
cause severe damage to crank bearings, etc. Get a jack. Easier and safer.
cause severe damage to crank bearings, etc. Get a jack. Easier and safer.
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Aftermarket head? I had aftermarket head on an M7 and it would do this...Higher compression causing lower exhaust temps and not working within pipes designed temp range...
I'm about ready to burn this thing to the ground!!!! I'm pulling my hair out!!!!
Went out today marked the clutches only using about 3/4 of the primary and only 7800 RPM in the powder. With 65 gram weights and 335 finish rate spring. So I tried a 360 Finish rate to see if I could get some RPM no luck still only using about 3/4 and only got about 7900 RPM. Trenching like a fat cow and not much track speed. Didn't get a chance to look at speed but I could tell it was way low.
Guess I'm going to order a secondary hell maybe even a primary and a alignment tool.
Oh yeah tried a new belt as well with no luck.
Went out today marked the clutches only using about 3/4 of the primary and only 7800 RPM in the powder. With 65 gram weights and 335 finish rate spring. So I tried a 360 Finish rate to see if I could get some RPM no luck still only using about 3/4 and only got about 7900 RPM. Trenching like a fat cow and not much track speed. Didn't get a chance to look at speed but I could tell it was way low.
Guess I'm going to order a secondary hell maybe even a primary and a alignment tool.
Oh yeah tried a new belt as well with no luck.
I was having a problem with it before the mods. But just figured it was a combination of the spring snow and lack of adjusting the clutching.
Figured the mods would at least get me some more power. But I've yet to see any gain from this kit.
What elevation are you riding? A 360 finish rate with 65 gram weights just doesn't sound right to me. Your finish rate is WAY to high (IMO) your weights cant overcome that spring. I would get your secondary fixed or replaced and drop that primary spring to a cat yellow white (285 finish) just to see if you can get more shift out.
It is way wrong. But what I was trying to do was get it to rev. I figured it wouldn't shift out all the way but it should have at least reved past 7900.
Anybody messed with or heard of the Ignition Timing Sensors going bad. I'm going to ohm mine out but thought I would ask. Can they go bad without having major problems.
Unplug all added electronics, make a quick wot pull, real quick, 3-4 seconds just to see if it hits rpm.
