Ecu
 

just want to check that yamaha dealers have to replace old ecu under warranty even if the bikes were bought second hand. I have a 2005 xt with the old ECU and the bike fluffs out when blipping the throttle going down gears .was this a recall ? Can my local dealer refuse to replace it ?

Have a look in the modification index under recalls.

http://www.xt660.com/showthread.php?t=630

Your problem sounds as it may be the TPS. Get back to me if Yamaha don't come to the party & we will see what we can do for you.

The TPS was sorted in a recall. Can you tell me , the faulty ECU does this breakdown and stop the bike running or was it just replaced to make the bike run smoother, i was out today and the bike is not to bad but i noticed the new plug i put in is a touch white so i think i"ll adjust the mixture seems a bit weak this might help with the popping from the pipes when i role off .

Be careful there was quite a few of us that had the TPS recall done & the dealer fitted the same faulty type of TPS back on to our bikes.

I worked this one out a few years ago on my 04 XTX, my bike started to cut out after the recall. Remove the TPS & give me the numbers on the back of it. A 45, 47 are no good & a 46 is good, look for these numbers.

Just wanted to check again, does the faulty ECU cause the bike to stop or was it replaced just to help with the surging

The ECU was changed for surging. The TPS was change for cutting out when pulling in the clutch, while slowing down & blipping the throttle.

This is my second xt and the surging on this one isn"t to bad ,the TPS is set at 16 and i have upped the co by 7 to 32 from 25 because the plug was white ,would this increase in the co be enough to richen the mixture ,i have also blocked off the AIS pipe as you recommended . Are there any other mods that might help smooth the bikes power delivery i"m not to worried about increasing the bhp.It had been fluffing out a bit when the throttle was blipped coming down the gears but only very occasionally and i have put this down to the weak mixture . I am hoping the new co setting will help this but haven"t had a chance to test it yet. Thanks for all the help

CO1 only adjusts the A/F ratio at part throttle which is 16 to 18 on the TPS, over that reading the bike runs on the fuel map & would need a fuelling device to correct the A/F ratio between 18 to 100 on the TPS.

So is there any other way to make the bike run richer thoughout the whole rev range

The only way is using a fuelling device. There are many out there have a look in the mod section for your choice.