**Fuel Injector Overfueling** - .: XT660.com

RickM · # 1 24-08-10, 16:14

Just had my first "major" issue with my 09 Ten and thought I'd better share it in case there is a common problem (my dealer has asked for photo's so he can inform Yamaha).

Whilst returning home from Birmingham last Thursday I ran out of petrol prematurely after only 59 miles on reserve instead of the usual 80-90 miles.
I normally ride at half to three quarters throttle hence 60-65mpg. As reserve is 6.3 litres, 59 miles equates to about only 42.5mpg!! Even allowing for thrashing the bike, the lowest I've had previously was approx 55mpg.
After a little top-up the bike wouldn't start but stunk badly of petrol.

Spent most of the weekend checking all the usual culprits to eliminate them. On the one occasion that I did manage to briefly start the engine a considerable amount of unburnt petrol was ejected from the silencers - not the usual misfiring situation I've experienced before with previous bikes!

Whilst checking the injector (I assumed it had stuck open somehow) I noticed signs of corrosion around the FI lead and frame.

The FI lead exits the wiring loom between the loom and the frame. As such the paint had rubbed off the frame and the red/black wire of the FI lead (to ECU) had chafed to the bare wire and so was shorting against the frame!! My first thought was "that's a clever bit assembly-NOT" (or words to that effect!)

Needless to say, bike runs fine now that I've patched it all up.

Being a courier I do alot of miles - over 51,000 since end of March 09 - but regardless of more than average wear and tear this struck me as a breakdown waiting to happen.

Might be worth Tenere owners checking their wiring loom just in case.......especially if they experience misfires/bad running with excessive amounts of unburnt fuel.

And put some foam between the loom and the frame

Hope this is of use.

Cheers,
Rick

PS. Do the X's & R's share a similar wiring loom???

Skunkmoto · # 2 24-08-10, 17:06

When I put a powercommander on I noticed the very same thing, and put a bit of foam tween the wires and frame.

Thought I'd posted something on this see here http://www.xt660.com/showthread.php?...highlight=loom

RickM · # 3 24-08-10, 20:22

Well b*gger me!

I obviously missed that one. Just shows how sensible you were!!

Kev · # 4 24-08-10, 23:25

Nice find that would explain the extra fuel.

The injector works off a Pulsed Width Modulated signal with the ECU controlling the earth side of the injector, if you earth that wire out the injectors duty cycle will up to a 100% depending on how good the wire was to ground.

RickM · # 5 25-08-10, 01:33

Thanks alot for confirming that Kev.
When I tried to explain the situation to my dealer (I was worried about the petrol in the oil and any subsequent warranty issues) the young mechanic got all text book like about switched earths unlikely to be from the ECU. I was starting to wonder if the FI lead was just a coincidence to my problem. 100% duty would explain the amount of petrol in the engine oil!!

I guess the FI lead is potentially just another addition to the list of known issues???

Anyways, the Tenere is still a great bike - at least it was at last years price!!

Kev · # 6 25-08-10, 02:07

Thanks for this info, it is one to watch out for, I am sure all the XTZ boys will check their looms as soon as possible, I know i would be checking mine if I owned a XTZ.

This have given me an idea to make a section in the XTZ mod index of K now Faults & Fixes to a XT660Z, now loacted at the end of the XTZ mod index. I will get all the other know faults & add it to the subject soon.

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

RickM · # 7 25-08-10, 11:51

Glad my day of lost earnings and weekend in the garage hasn't been in vain!

buzzlightyear · # 8 08-09-10, 21:37

Rick, were those photos taken with the tank off, on the rhs frame?

offroadtoad · # 9 08-09-10, 21:48

I was going to ask a similar question – can I get at the area in question to check the wiring without removing the tank??

The images are great at showing the point where the cables rub the frame, but I can't figure out where on the bike I need to actually look for this

With over 5000 on by Ten now I think it's about time I took a look

Oh… and just out of interest, have you encountered many other problems during those 51,000 miles?? Makes my 5000 look a little weedy

RickM · # 10 08-09-10, 22:50

Yes buzzlightyear - RHS side of frame under the tank.

Offroadtoad - You do need to remove the tank but it's not that difficult if it's empty(ish). Just be careful when disconnecting the fuel hose from the pump not to snap the plastic pipe off!! - the connector can be stiff. In the absence of any other pics at the mo, hopefully the attached one make's it a bit clearer where to look under the tank. (Airbox to left of pic, engine/valve inspection cover to the right with the throttle assembly & FI w/lead in the middle).

As for any problems/issues I've encountered over my current 53,000 miles, they've pretty much already been discussed (cush drive rubbers, seat). Rear disc will probably need replacing soon.
The high mileage is due to me being a courier and fortunately mostly due to prolonged steady/smooth riding (err - mostly) up the A3 to London from Guildford with the occasional distance work. Would be interesting to compare my engine sound/vibes with a low mileage Tenere to see if things are starting to get too loose now though. (Single cylinder paranoia setting in).

There is one particular issue that has become ever more prevalent though - the lack of any alternative bike that suits me! Being used to a trail bike with a consistent 60-65 mpg regardless of riding environment (within reason) kinda limits the choice!!
Until Suzuki wake up and smell the roses!! Fuel injected DR650/750/800????!!!

BTW, all's well so far since sorting my FI lead. Managed 240 miles before F-trip came on once last week!

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