Screw the programmer, make sure that you get the FI adjustemnt tool first
The yamaha Power Tuner will not help a tiniest bit with starting problems,
the FI tool is your idle mixture screw of old. What good is optimized power delivery, when
you get left in the dust by all the others the first time you stall you bike?
Buddy of mine had to work quite some time on his 450EXC until he got it to start perfectly.
He claimed even 1/8th of a turn of the mixturce screw makes a day and night difference
with regard to starting, especially when in gear.
But we EFI bike riders don't have such mixture screw, we are invited to shell out money to but it.
Everyone was pointing out one should richen the mixture by going to +8 on the CO setting.
So did I, and it was an embarrasment to ride in the woods with my buddies. Everything, even the
stock WR250F of another friend was firing up better than my '12 WR450F. I developed a demonstrable
technique of needing three(!) attempts to "most probably" get it going when stalled.
Sometimes I even had to get it in neutral.
The preowner supplied me with the hint that when warm "she starts much better when you
gently lift the cold-start knob to just before it notches". Sounded like a very strange advice to me,
especially as this meant he'd put his left hand onto the knob, hence he couldn't have stated her in gear when hot
Back home in my third week of EFI WR ownership I hooked up the CO adjustment tool (actually the
FI tool in CO adjustment mode) and kept lowering the idle speed to as low as 1400 and while checking
the rich end of the CO setting where the engine would die and the lean end, aiming for the middle in between.
I ended up with a CO setting of -4 (or -6, I forgot) what would normally be called "very lean" an idle
and now the very same bike fires up great in gear! (Of course I increased idle speed to a sensible level afterwards)
Just today in the cold (~60°F) basement parking garage I dared not to pull the "choke" but to be
even more hideous by putting her deliberately in gear (rocking fore and aft to free the clutch)
and she fired right up! Of course she didn't idle for long, being cold like that. So while still in gear
I simply hit the button a second time cracking throttle open a hair after she fired up and she idled nicely!
When you dial in the CO value correctly (ignore the number, go for the behaviour)
a WR, that was hard to start even when waremd up, let alone in gear,
WILL turn into a perfectly starting bike!
The fact that it did start up cold w/o pulling the cold-start button normally would indicate too rich an idle
mixture on a carbed bike. The EFI however, appears to "know" the engine and air temps and adds
cold start fuel by itself IF and only IF there is enough air to burn it. Seeing the throttle to be fully closed
and sensing via MAP sensor that one didn't pull to cold-start button it can only inject so much, which
is not enough to keep running.
Either the pulled cold-start button (MAP sensor) or the very slightly opened throttle (TPS) tell the EFI system
that it may add the amount of fuel it deems necessary for the cold engine.
I'm pretty sure that the cold-start button technically is unnecessary, except for folks who are too throttle happy
to just slightly open and hold the throttle when starting OR those ex.- two-smoke riders who have internalized
the habit of blipping the throttle while kicking.
So with the CO mixture set correctly you should be able to start in gear and even cold start (provided you manage
to open the throttle only a tiny bit and hold it there) w/o having to put her in neutral or reach for the hot/cold-start button.
Mine is a '12, Im the second owner, I'm pretty sure no one did change starter brushes and I've no idea how old
the battery is. When the CO is right the yamaha e-start setup is absolutely sufficient.
I'm running a YZ'06 exhaust cam, but I do not think that YZ timing had any positive contribution to e-starting.
Literature claims, that the smaller LSA (lobe speratation angle) of YZ timing tendentially would "lower idle quality"
In my case that effect definitely was cancelled out by the correctly set idle mixture.
Edited by WRF-Rowdy, June 14, 2015 - 11:31 PM.