I have the Australian restricted model MT07. I reflashed the ECU and have Akra snail pipe and DNA filter and the throttle rotation restrictor was removed, but the dyno run revealed sill only 54rear wheel HP.
Now the reflash was to Euro spec so the only difference should be the 655ccrelarive to 688cc and the resulting .5 integer decrease in compression ratio. As far as i can make out the has been no cam or valve changes.
Getting hold of the dyno run graph of hp/revs and AFR/revs and comparing them to the published curves for various products on the net I discovered that up to 5000rpm they are all pretty much the same as mine BUT after that the AFR gets richer and richer and the power starts to flatten out.
First thought was gas flow restricton. Either exhaust ( used a fair bit in the 70's and 80's) or an airbox restriction. Crude but reasonably effective in cutting the balls off the power.
SOOOOO... I first went and watched alll the videos on the introduction of the Aussie model and in one , and one only, the reviewer mentioned an airbox restrictor. Time for some mining.
WARNING!!!! Do not do this if you any in any way inexperienced. There are a whole heap of connections that are brittle and easily broken and MUCH finesse is needed to accomplish the following.
Taking off the airbox on the MT is a complete pain in the butt.
First remove the tank. Remove the filter cover and filter.
You actually have to remove all of the connections to the throttle bodies both mechanical and electronic and air tubes and the fuel line. Undo the rubber manifold allen bolts on both sides of each of the throttle bodies. Undo the airbox hoses and airbox bolts. Undo the anti knock sensor connector ( I think that is what it is) . The throttle bodies have to move down to get them out and the wires are in the way.
THEN lever the throttle bodies towards the back of the bike and slip out the front manifolds between the engine and the throttle bodies . The bolts have to be very loose.to come off the throttle bodies and the engine.
Move the throttle bodies towards the front of the bike and downwards past the knock sensor. You have to turn them a bit.
The airbox will come out without forcing with very careful alignment as you move it forward and down.
OK the revelation. The airbox internal stacks have a very crude double right angled ledge completely around the inside of the entrance to the throttle bodies butting against them. the throttle body inlet is 41mm. The restrictor is 30mm. That restricts the flow to about 53% ( actually less because of the shape of the restriction..
The Stacks are that rubber usually used for motorcycle stacks and is easily worked on. I used a dremel and a grit cylinder bit. and opened the hole out to match the throttle body.
BTW the manifold matching at the engine/throttle body is a little rough as well so I matched it at the same time . On this area the aluminium of the head actually has to be matched not the rubber.
Now the reflash was to Euro spec so the only difference should be the 655ccrelarive to 688cc and the resulting .5 integer decrease in compression ratio. As far as i can make out the has been no cam or valve changes.
Getting hold of the dyno run graph of hp/revs and AFR/revs and comparing them to the published curves for various products on the net I discovered that up to 5000rpm they are all pretty much the same as mine BUT after that the AFR gets richer and richer and the power starts to flatten out.
First thought was gas flow restricton. Either exhaust ( used a fair bit in the 70's and 80's) or an airbox restriction. Crude but reasonably effective in cutting the balls off the power.
SOOOOO... I first went and watched alll the videos on the introduction of the Aussie model and in one , and one only, the reviewer mentioned an airbox restrictor. Time for some mining.
WARNING!!!! Do not do this if you any in any way inexperienced. There are a whole heap of connections that are brittle and easily broken and MUCH finesse is needed to accomplish the following.
Taking off the airbox on the MT is a complete pain in the butt.
First remove the tank. Remove the filter cover and filter.
You actually have to remove all of the connections to the throttle bodies both mechanical and electronic and air tubes and the fuel line. Undo the rubber manifold allen bolts on both sides of each of the throttle bodies. Undo the airbox hoses and airbox bolts. Undo the anti knock sensor connector ( I think that is what it is) . The throttle bodies have to move down to get them out and the wires are in the way.
THEN lever the throttle bodies towards the back of the bike and slip out the front manifolds between the engine and the throttle bodies . The bolts have to be very loose.to come off the throttle bodies and the engine.
Move the throttle bodies towards the front of the bike and downwards past the knock sensor. You have to turn them a bit.
The airbox will come out without forcing with very careful alignment as you move it forward and down.
OK the revelation. The airbox internal stacks have a very crude double right angled ledge completely around the inside of the entrance to the throttle bodies butting against them. the throttle body inlet is 41mm. The restrictor is 30mm. That restricts the flow to about 53% ( actually less because of the shape of the restriction..
The Stacks are that rubber usually used for motorcycle stacks and is easily worked on. I used a dremel and a grit cylinder bit. and opened the hole out to match the throttle body.
BTW the manifold matching at the engine/throttle body is a little rough as well so I matched it at the same time . On this area the aluminium of the head actually has to be matched not the rubber.
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