RPMS still down..

Dumb question...did you wrap the helix the right direction? Stock secondary spring is pink. We switch all 5 Apex's in our riding group to white at 60 wrap. None of them have any issues hitting 10,800 to 11,000 rpm.
As others mentioned, make sure the track spins freely. Remove the belt and hike the back in the air and turn the track by hand. Should be easy to rotate but, is hard to move with the belt on it. If someone put a track in it they may not have assembled it correctly. Brake could be hanging up, parking brake could be hanging up. It is supposed to have two small aluminum spacers under it to line it up with the brake rotor. Something in the chain case may not have been assembled correctly. The shifting fork for reverse can be a little bit of a PIA to get assembled correctly. Chain tension too tight, should just set the adjuster bolt finger tight and back it off a little and lock it down.
You mentioned you replaced the plugs. Sure all the wires are in right coil packs?
Don't know about the fuel pumps as we never had one fail.
 
iahacker said:
Dumb question...did you wrap the helix the right direction? Stock secondary spring is pink. We switch all 5 Apex's in our riding group to white at 60 wrap. None of them have any issues hitting 10,800 to 11,000 rpm.
As others mentioned, make sure the track spins freely. Remove the belt and hike the back in the air and turn the track by hand. Should be easy to rotate but, is hard to move with the belt on it. If someone put a track in it they may not have assembled it correctly. Brake could be hanging up, parking brake could be hanging up. It is supposed to have two small aluminum spacers under it to line it up with the brake rotor. Something in the chain case may not have been assembled correctly. The shifting fork for reverse can be a little bit of a PIA to get assembled correctly. Chain tension too tight, should just set the adjuster bolt finger tight and back it off a little and lock it down.
You mentioned you replaced the plugs. Sure all the wires are in right coil packs?
Don't know about the fuel pumps as we never had one fail.
Click to expand...

Yea coil packs are reinstalled properly...secondary spring is white wrapped at 60 in the right direction. Tried wrapping it at 70 last night. Made the clutching a little more aggressive. Saw 10k rpms on the road for a second, but holding at wot throttle it wants to run 9k to 9500. The track spins freely and my belt deflection is perfect. I'm going to pull the stock weights and redo the rivets to stock. I'm wondering if the previous owner had engine mods and removed them but never put the clutching back to stock.
 
One other thought. Just because you have new plugs doesn't mean they are 100% good. New ones can be bad or work part time. May be worth a second look. They are small delicate little SOB's and a bit of a trick to get them in. Maybe the gap in one of them has been pushed closed. You mentioned flat rev response and back fire which isn't normal. My nephews 06 attak is a little flat on rev but never back fires. We have another 08 that revs clean as does my 11. Don't know what the difference is but all run clean under load. The fuel mapping is a little different from year to year. There is a parameter that you can access through the gauge pod to ad more fuel on low end to clean up the flat spot.
Check all the simple stuff first and eliminate one at a time and move on.
Stock weights I believe have the 17.2 rivets in all three holes if I remember correctly. Check the part number on the weight that are in it. Should have 8FP 00 on them. If someone tried to put 2011 or newer weight in it, the engine won't pull them as they are about 93 grams gross weight.
 
I'm on my second set of plugs just to rule the out of the equation..and yea they are a PITA! My back fire issue is a ton better than it originally was. I'll still get a small backfire every once in a while. I put a like new airbox on it to rule out any issues there. Went through all the ground blocks, dialectic greased all connectors etc..If I pull the belt, and hit the throttle it revs right up and hits the Rev limiter. So it only acts funky under load. The stock 8FP weights are installed, but I never checked the rivets. I think that's my next check point.
 
weigh the whole arm with rivits in it to get total weight in grams on like a cheap kitchen scale or sumptin
 
thats what we need to find out now !just to verify stock setup, im sure somone on here knows! mine has a dalton clutch kit in it , but i know my arms r 58 grams empty, 61 grams loaded, ( has only 1 tip rivit), from what iv herd 1 gram will change 100 rpm
 
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67.8 grams if they r 8fp 00
 
should have 3 4.5 gram rivits in it so i think you at 81 total weight is proper stock setup, if this problem u have under load was in a car i would be checking ignition timing, ir a jumped timing chain tooth, think the chains in apex r self adjusting , just throwin it out there!!!
 
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Yea I was just reading up on that too. Looks like the weight is 67.8 and the 17.2mm rivets are 4.5g a piece.

One other thing Ive noticed. While having the clutch apart sitting on the bench, the outside sheeve has resistance when sliding up and down. I know from experience on older yamahas that there was 0 resistance with those.
 
yes outside should just slip n slide!
 
I'm starting to think that is the overall issue. It was sticking before I had it rebuilt...which is why i replaced all bushings and even put a new spider assembly on. It still has a good amount friction after the rebuild. I also noticed a similar amount of friction with my 2012 vector, which has 800 miles on it.
 
srxr700 said:
I'm starting to think that is the overall issue. It was sticking before I had it rebuilt...which is why i replaced all bushings and even put a new spider assembly on. It still has a good amount friction after the rebuild. I also noticed a similar amount of friction with my 2012 vector, which has 800 miles on it.
Click to expand...
If the clutch is binding & not letting it shift out I would suspect the RPM's to be higher if anything. Does the rpm drop more on long lake pulls? If so, it could possibly be a tight valve. The more it heats up the more power you loose with a tight valve.
 
I put about 50 miles on it this weekend and overall it ran like a champ. Hit 105 on the dream meter on packed trails and had really nice mid range performance. There's no ice here safe enough in Michigan to run it on. On icy roads it would hit 9700/9800 rpms and drop and stay at around 9100.
 
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