XT660X - restricted or just no oomph
 

picked up a 56 Xt660x in orange and black and it's basically bloody awful to ride. Around town the thing is lurching and hunting and doesn't settle down. Second gear the thing is racing ahead one minute, stuttering the next and third is like it's about to stall completely. Thought it might redeem itself out on the open road but it's lumbering up through the gears before topping out a little over 80. Is this typical for them or is it perhaps restricted and the dealer didn't know before selling it on? I know it's never going to match my fazer thou for sheer speed, top end etc but had reasonable expectations that a large 660 thumper would offer some thrills between 0 and 60 but this thing is souless and bloody hard work to ride. In the wet on diesel covered roundabouts in town it's verging on lethal.

any thoughts ideas?


***just read some of the threads n stickies on the rubbish fuelling but doesn't seem to explain the lack of get up and go the thing doesn't have***

:hello: and :welcome: to :660:

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

Hi and welcome 80 mph sounds restricted to me one of the lads whos bike is restricted gets about 85mph on the XTR http://www.xt660.com/images/icons/icon7.gif http://www.xt660.com/images/icons/icon14.gif

Sounds like your bikes been restricted as an unrestricted bike should be able to hit 100mph or so. Also you may want to turn the tick over up a little as this should stop the bike from lurching as much. also a set of filters like K&N or DNA and a kev fuel mod should reduce the lurching.

Wow guys what a wonderful welcome :YouRock:- thank you ever so much for the various bits of advice. Will take some time, read through and speak to my local dealer to see if I can get the old girl sorted out.

Not too sure where the restrictor is, but should be some where in the air intake, and should be easily removed.

The rest of the stuff is just taking your time and fiddling with this bit, take it for a ride, fiddle with that bit etc etc

Its like any bike its never going to be 100% what you want so you spend time messing with bits and bobs to get it right

If it is a restricted bike it would have an L shaped metal clip that is fitted to the throttle body where the throttle cable joins it, and that is there only to prevent the bike to be revved at top wack. It is easy to remove, but judging from the symthoms I am doubting this bike is restricted and I would most certainly suspect that we have a case of faulty TPS and or ECU.

Let's wait til he has it seen by a Yamaha official dealer.

Old thread
 

I guess this is a pretty old thread, but since I just moved from 2001 Fazer 600 to 2005-7 (00 ecu) XTX I guess I could comment on this.

From 0-50 the XTX can hold it's own surprisingly well, the torque does help. However, it absolutely cannot match the Fazer when it comes to straight road acceleration or engine smoothness. Fazer is smooth as silk, especially the carb versions are one of the smoothest bikes I've ever ridden.

Most likely you rode either restricted or somehow broken bike, and the experience was made worse because you compared the bike to Fazer (not to mention if you were comparing to 1000cc one)

My XTX does about 100, but I would not want to do that all the time, the vibrations get really bad. On a small country road the tide turns, on bad tarmac my XTX is way faster than my Fazer used to be and also more fun to ride. Finland is full of these roads, so for me the choice is easy (it's also the fact that if I get caught speeding on the Fazer near at it's fun point, I won't see my license for months and the fine alone is going to be about 1 month salary).