Urgent: In the middle of travel, unstable throttle

[ddartt]

Hi guys,

Not sure which is the best section of form for this, but would really appreciate some advise asap, as I'm stuck in the middle of Pyrenees in some small town.

Basically, the throttle all of a sudden started to play really weird - acceleration and likewise engine braking is not stable as if there is a problem with fuel supply, the bike is dragging back and forward. I can ride it further but its a nightmare. The last petrol place in France looked a bit dodgy so it might be bad fuel (I've refueled it since), going to check fuel hoses as well, where else should I look? It seems like a problem with mixture. But idle is totally fine and stable.

Any advise? Bike is fz6 06, done servicing recently, about 3k miles ago.

Thanks a lot!

 

[TownsendsFJR1300]

If fuel (and it sounds like it) is the issue, find someplace with some basic tools to pull off the fuel tank.


You actually may have enough in your stock Yamaha tool bag to do it.

Pull the tank, flip it upside down and dump it in a container. You'll see very easily if you have water in the fuel. Get as much out as you can. Even pump some fresh fuel in there and dump again (flush it).

Re-assemble, you know the rest..

Please post how it works out for you and good luck...

(You didn't mention any error codes, I'm assuming there aren't any)

 

[Motogiro]

:welcome:to the forum!

It could very well be bad fuel. The symptoms are also in line with a Throttle Position Sensor (TPS) problem. I'm thinking at idle it's okay but when you open the throttle, that part of the TPS wiper has gone bad. There is a way to check the TPS from your instrument readout by putting it in diagnostic mode.

Here's a link with instruction on how to test the TPS. http://www.600riders.com/forum/fz6-...r-idle-mileage-stalls.html?highlight=throttle

You should see the numbers change smoothly as you rotate the throttle very slowly. I would do this test 1st to eliminate it.

 

[ddartt]

Thanks! Quick question before I go ahead - will I do any damage to the bike if I just ride it dry and fill up with fresh fuel, rather than dumping the old one?

 

[Motogiro]

Thanks! Quick question before I go ahead - will I do any damage to the bike if I just ride it dry and fill up with fresh fuel, rather than dumping the old one?

If you got bad fuel it would be better to dump it to keep you fuel system freer of contaminants especially if you don't know what's in there.
Check your TPS first because it may not be bad fuel...

 

[ddartt]

TPS seems to be fine, 16 when throttle closed and 100 whopened. Going to do the fuel exercise now, first will dump some to bottle to see if I can see the water. Its not too easy to find a place to dump fuel around in an environmentally friendly way...

 

[FinalImpact]

If your sucking water which is the most common fuel issue, low speed and off idle will be the worst conditions as a straight does of water will not burn and can stall the engine. At higher RPMs it can deal with more water.

- keep it sloshed and mixed
- get a gas dryer in there

Add a fuel dryer to mix and extract the moisture. It can't hurt. If stuck in town and you must be at idle, remember that water is heavier than gas. If not being agitated the water will go to the bottom and be picked up. << Save this for cruising speed. While at low speed slosh the tank to keep the heavy water separated and off the tanks bottom.

^^ assuming dumping is not an option.

 

[ddartt]

Thanks, guys! Its getting late here and the small fuel station doesn't stock dry gas. Will try my luck in the auto shop tomorrow, I guess I just have to carry on, no bike shops around anyway. Will make sure to shake the tank in the morning. )) But will be checking the forum in case there are other advises as well.

Thanks so much everyone for your help!

 

[TownsendsFJR1300]

If you can find some K100 (not likely): Fuel Treatment, Fuel and Gas Additive | K-100 HOME it works EXTREMLY well.

It keeps the water mixed with the fuel and you literally burn it off as you ride. Been using it in the boat for 2.5 years, 5o gallon built in tank, 1996 boat, NEVER HAD the tank out.

Not knowing what you pumped in there, maybe a real gas station has a clean container you can dump it in and see what comes out. It'll be very obvious, separating blobs of water, cloudyness, etc if its water. Flush until its clean.

Hopefully that's all it is.

I wouldn't ride anymore than you have to at this point as IF there is crap itself, you don't want to suck that into the fuel filter..

 

[ddartt]

Just reporting back on this one. One thing I didn't mention thinking its a pure coincidence but looks like I should have. The problems have started on a mountain pass. Today it started fine, but as I got up to 2km altitude, the engine began to misbehave, stalling on idle (with smell of unburned fuel off the exhaust). Not sure of the cause (as I understand the FI bikes should compensate for the alt), but bumped the idle throttle (was a but low), refueled the bike and it seems fine now.

 

[Motogiro]

Just reporting back on this one. One thing I didn't mention thinking its a pure coincidence but looks like I should have. The problems have started on a mountain pass. Today it started fine, but as I got up to 2km altitude, the engine began to misbehave, stalling on idle (with smell of unburned fuel off the exhaust). Not sure of the cause (as I understand the FI bikes should compensate for the alt), but bumped the idle throttle (was a but low), refueled the bike and it seems fine now.

Could also be the intake air pressure sensor.
Read here... http://www.600riders.com/forum/fz6-technical/45265-fault-code-14-a.html

 

[yamihoe]

I would have just pulled off the line from the pump and put a piece of 5/16 hose on the end and turned the ignition on and let the fuel pump out into a bottle or something...
but get a pic of you holding the tank upsidown up high,,,, we can call it the gas dance Blah

 

[Motogiro]

I would have just pulled off the line from the pump and put a piece of 5/16 hose on the end and turned the ignition on and let the fuel pump out into a bottle or something...
but get a pic of you holding the tank upsidown up high,,,, we can call it the gas dance Blah

If you have a large amount of debris/contaminate it's better to dump the tank as apposed to possibly bogging the internal pump filter.

 

[TownsendsFJR1300]

I would have just pulled off the line from the pump and put a piece of 5/16 hose on the end and turned the ignition on and let the fuel pump out into a bottle or something...
but get a pic of you holding the tank upsidown up high,,,, we can call it the gas dance Blah

Done the gas dance a couple of times, quite messy and definitly not fun.

Besides not wanting to suck any crap thru the filter, thay valve at the bottom of the tank is "closed" when the factory line isn't hooked up and won't flow.

Even if it did, I don't think the pump will keep running wth no oil pressure(engine not running)