Flooding and Fouled Plugs-Anyone Else Experience This?

[jaquima]

[NOTE TO NEW OWNERS: The OP has a 2011-2013 Gen1 bike and many of those year bikes had a condition called "hard start." His description of the problem and cure are a good summary for the 46+ page thread about it elsewhere.
Yamaha addressed it in the Gen2 2014+ bikes and while there may've been a couple of people to experience a hard start, the problem is largely a Gen1 issue.
CW - mod]

For the second time since I have owned my ST (bought it in August 2011), I was not not able to start it due to fouled plugs. After checking everything I could think of, and everything described by the service manual, I deferred to my local mechanic (one man shop). He discovered that every time I turn the key to the run position, the bike's injectors also turn on making it mandatory for me to start the bike to clear the gas. Turns out, the two times the bike would not start with fouled plugs was the result of me turning the key to record the mileage (after oil changes) but not starting it. When I tried starting the bike after each of those two instances, the plugs were extremely fouled and the bike would not start.

Since that time, I have learned to:
1. Use the kill switch to turn off the motor instead of the key.
2. Start the engine by turning the key to the run position before switching the kill switch back to the run position as well. Evidently, turning the key to the run position with the kill switch in the off position prevents the bike's injectors from working before the start button is pressed.

Just wondering if anyone else has had this happen and if so, maybe try using this start sequence to prevent any future non-starts.

 

[tomatocity]

Thank you for that information. Did not know the injector issue and I do check my mileage as you did. Note to self...

 

[Don in Lodi]

You're describing the infamous "Hard Start".

 

[2daMax]

I always put the the Kill Switch to OFF before starting, or when I remember, after key off, I will put the Kill switch to off. Read about this somewhere on the Hard Start issues.

I am not sure if shutting off the bike via the kill switch or Key Off makes any difference; i have not found any difference.

Slightly off topic, using iridiums Denso IU24 makes starting a tad harder. The engine is slow to catch on and sometimes miss a beat.

 

[AVGeek]

On my Gen 1 bike, I swapped out the start switch cluster to the 2013 FJR style, which made it's way onto the Gen 2 bikes. I got into the habit of only using the kill switch to shut off the motor, and never experienced the hard start issue, even when cycling the key multiple times as I worked on electrical projects.

 

[RED CAT]

Never had any of these problems but then I don't turn the key on except to start the bike.

 

[Tenman]

I've had 3 hardstarts in 4 years and 35000 miles. After the last one. I got home and turned my key on and off a bunch of times trying to flood it. Nothing happened. She fired right up.

 

[ST-venture]

Since that time, I have learned to:
1. Use the kill switch to turn off the motor instead of the key.
2. Start the engine by turning the key to the run position before switching the kill switch back to the run position as well. Evidently, turning the key to the run position with the kill switch in the off position prevents the bike's injectors from working before the start button is pressed.

Just wondering if anyone else has had this happen and if so, maybe try using this start sequence to prevent any future non-starts.

I had been using this routine for over a year and for the most part it helped with the hard start / flooding issue I had with my 2012. But last fall after experiencing several near starting problems while on a trip to TX, I had the battery replaced. The shop said the battery tested at about 75% of capacity and it was technically still good. But after replacing the battery I have not had ANY starting issues. Even when not using the kill switch routine.
The older bikes seem to be very sensitive to battery voltage.

 

[WJBertrand]

Seems like running some fuel injection cleaner through the system regularly might help this. Even though the fuel pump is activated when the key and kill switches are in their ON positions, the injectors should not leak. Perhaps as miles accumulate the injectors can get a bit dirty and not close completely?

 

[AVGeek]

Seems like running some fuel injection cleaner through the system regularly might help this. Even though the fuel pump is activated when the key and kill switches are in their ON positions, the injectors should not leak. Perhaps as miles accumulate the injectors can get a bit dirty and not close completely?

My 2012 got an almost exclusive diet of Chevron fuel. I know the cleaning agents seem to be a lot of marketing hype, but I never experienced the hard start issue, even when the stock battery died on me, and I was push starting the bike. As an aside, I also found that I could disable the ABS when trying to push start and use 2nd gear...