YZF 750R Problem

[MarktheMuffin]

Hi All

Have just got my YZF back on the road (three/four weeks ago) but now have a prob that just cannot be found or pin pointed to one spot. I have been told by the guy that did the MOT that it could be a number of things that add up to one, both electrical, but would take him a while to find the right fault. This is what happens when riding the bike.

Around Town - When in this situation all can be ok but then all of a sudden the engine would just die at a junction and be a bitch to start or I can be just going along at a steady 30mph and then have no power but would pick up again like it had kangeroo juice in the tank, more noticed in higher gears as i would have to drop down to third or fourth all the time, second/third in a 20mph area even with clear road.

Out of Town/Open Road - I have a lot of dual bypass where I live and know what the bike can do on it but not now, this is where it is more noticed when riding, 60mph plodding along and then nothing, again no power, revs die down, ease back on throttle and then it will start to pick up again so long as I very slowly start to open throttle again, gone is the time where I could drop it down a gear or two and then hit the throttle to over take to hit the next clear bit of open road. Sometimes it would just do it and then, yes you guessed it!, lack of revs, loss of power and speed, this is not good fun when I have just over taken something also doing 60mph and then have to think about whats coming up my rear while the bike has a hippy fit, it's like there is no electrical power being returned to the bike, no heart beat to keep the stroke going when feeding the blood of life. The bike has started to back fire since being back on the road, but only now and then, or when over reved. Idle speed differs from 800 to 1500, then back to 800 and so on all the time, was set to 1100 dead and was set like this up untill November last year 2012, new MOT in June 2013.

Usual bits and bobs done for the MOT, no probs, tyres,oil,filters,brakes,plugs. All done passed. When I picked the bike up I was told that thay didnt have the right plugs for my bike but had fitted other plugs that had the same specs which fitted. Since these knew plugs have been fitted i smell the engine flooding when trying to start it, very strong smell of petrol, it never was before. What advise can you give me here?, forget it or fit recommended.

As for the main prob, my first thought was that the Exup valve might be on its way out or sticking as it did start giving me the signs of this, but eliminated this by hitting the bypass with a 100mph and the only time that it has done it since, with the prob i have now I am lucky to get to 90mph. It feels like an electrical prob to me but i dont know what to look at first with the amount of time on my hands at the moment (limited)

Have you had these probs, if so please help

Thanks

Mark