[Fallen Hero]

Okay before i get burned i have been trolling this forum ever since i bought my r1 8 months and have had every question ive ever had answered here but i cant find anything that matches my current situation.

Bought a 2008 this last spring as my first liter bike. Its faster than my r6 (which it should be, obviously) and ive been riding it contently up until today.

I took my bike to a very well respected dyno tech to get my bike all dialed in.
The first run showed 140 rwhp. But thats all he could get out of it and i know it should be close to 160-165 with supporting mods from everything ive seen on the forum. The power curve wasn't really a curve. Doesn't look like any of the r1 dyno sheets ive seen. its a flat line that runs diagonally. at 10k it doesn't begin to spike or anything, just keeps chugging along like it not even in a powerband.

i just assumed the feeling of 140 hp was a liter bike as its the only one ive been on.

mods include:
PCV
K&N air filter
new Iridium spark plugs
-1 up front
A&R race baffles
M4 Y-pipe
exup still connected
02 disconnected
regular maintenance, no smoke out of the exhaust, oil leaks ect.., i ride it hard but not abusively.
* does get bad gas milage (thought the tune would fix it). gas light turns on around 100-110 miles.

it was running very rich but when he tried to lean it out the bike started acting terribly. Checked the airbox, and everything we could think to check but couldn't find anything. Seems like its a top end mechanical issue. Even he was baffled and couldn't figure it out.

we came to the conclusion the timing chain tensioner might be loose and a cam jumped a tooth. pulled my valve cover off and the cams are aligned but i havent checked the crank position yet. it might be a weak/floating valve issue but it doesnt seem like it. doesnt match the 07 ecu issue but i might be wrong.

im not sure where to start. anyone ever have this issue? Im at a total loss.

Also sorry if this makes no sense. Been up wrenching and forum creeping and its now 4am.

 

[Fallen Hero]

just checked a last minute thing. both my exup cables are snapped. could this be a symptom of the exup valve being stuck closed?

 

[pR1mal]

just checked a last minute thing. both my exup cables are snapped. could this be a symptom of the exup valve being stuck closed?

Definitely.

Remove the pulley cover from the exup valve, wire the valve open, and take the bike for a ride.

If you've been riding the entire time you've owned the bike with broken exup cables and you've grown accustomed to the way the bike runs you're in for a surprise, be prepared for the fuel tank to hit you in the chest as the front wheel leaves the ground! :biggrin:

/You do lose some bottom end torque when you remove or disable the exup valve. On the other hand, without the exup you actually get to hear the sweet sound of your engine's true exhaust note. The deep tones, the rumble, the bark.

And, removing the exup transforms the way the bike feels with respect to engine braking.

This video was filmed by an R1 forum member, I think it was Ozzian. It shows the proper operating cycle.

 

[Deer_killer]

Interesting video. I figured it would operate at a grater range than that.

So, if EXUP cables are snapped, is the valve stuck in the 10° open range all the time? That would explain a lot for sure

 

[pR1mal]

Interesting video. I figured it would operate at a grater range than that.

So, if EXUP cables are snapped, is the valve stuck in the 10° open range all the time? That would explain a lot for sure

The valve itself is spring loaded, but I can't remember which position it assumes under spring pressure alone. Might be closed, might be opened.

The valve shaft bushings have been known to gall and freeze in any position.