and to

I understand your frustration, but while we are here to help people like you we need you to understand, we are not Yamaha, we don't sell these bikes, and we have no responsibility with individuals's problem.

What we are is an owner's community where many of us work as a team to try to address a problem first and then with the help of our mechanic experts member we try to identify the fault and suggest ways to correct them, based on our previous experience in relation to common faults and problems related to these bikes. Hence we are a "forum of discussions" striclty dedicated to the Yamaha X660X/R/Z bikes.

Once we've got that clear we can have a look at how we can help you.

It is safe to assume you have bought a 2nd hand bike from 2006, which is round about the time when Yamaha issued a recall on the TPS (Throttle Position Sensor) which was found to be faulty. It is likely that the previous owner might have sold the bike before the official recall letter from Yamaha had been sent to him and therefore the TPS has not been replaced, or the official letter was ignored from owner to owner in case of more previous owners.

In cases such as these you can go to any Yamaha official dealers and have them check the frame number on their database, by which they'll be able to tell you if this TPS swap has been done on your bike or not.

Now problem no. 2 from 2004 until late 2007 there has been a number of bikes which also had a faulty ECU engine control unit, which is the chip that is preprogrammed to run your fuelling, your air flow ratio, your rev limiter etc etc...

There are a few threads on these issues in this forum which you can find here:

http://www.xt660.com/showthread.php?t=8546

http://www.xt660.com/showthread.php?t=519

Bear in mind that Yamaha has changed ECU's to clients only provided their tests showed these to be faulty however an official recall was never issued for these, which is why I suggest you read through the 2nd link I have provided you because it gives you some further insight info.

Finally you need to also be made aware that these motors being a single cylinder are slightly restricted in terms of air inlet, infact our experts have found these bikes to benefit from as much air inlet as possible, which is why Kev for example has deviced a mod that help fixing the problem and companies like DynoJet have a specific Power Commander with maps suited to make this bike work to the best of its capacity.

Please take your time to read as much info as you can and you will find that 99% of the time we will have a fix or a solution for your problem, we really are a friendly bunch, and we will enjoy see you getting sorted and happy as larry.

Cheers mate and good luck.

Fran