Last weekend I did a 95 build with a 203 cam; I have a start problem that has plagued this bike even before I opened up the engine.

90% of the time it starts before the bike hits it's second revolution but sometimes it fails to start right up...engine is turning over but no fire; at this point I've learned to roll the throttle about 75% and then it starts.

Battery is not weak has lots of cranking power.

Could the start cycle be too lean for start? Maybe need to enrichen the MAP for the sart cycle?

Bike is a fuel injected 2006 SG with a power commander...DYNO tune is scheduled for June.

 

What's your compression? Anything 10:1 and over should have compression releases. Another option is change out the battery cables to something good like a set of Yooper cables. Thirdly how's your starter?

 

Dawg,

The starter is strong...the battery seems to push the starter without laboring.

My compression is just shy of 10:1

Strange that i have to give a fuel injected engine some throttle to start sometimes?

PCIII causing this? MAP too lean for start?

 

That sounds like the PCIII 'issue' that lots of people have starting on 06.

Without the PCIII it started on half a revolution. With the PCIII it takes 1.5-3 revs to start.
I don't think that hitting the throttle has anything to do with it, but I could be wrong.

If you take your seat off, you will see that when you hit the start button, the PCIII reboots.
Try not waiting for the engine light to turn off before starting. I bet it starts faster.

So turn on ignition, then the kill switch and start immediately.

There is an option to add fuel at startup but that is generally for big builds.

 

I have hadsome of thesame trouble with my build. I had to rethink whats going on during starting cycle. I did a little studying too. That helps. The old days you did what you did cause thats what you did but now you gotta think about it.
I use a SERT, which gives me the ability toRECORD things from the ECM.

When you hit the start button, for an instant the MAP, (related to vacuum), reads 80-100 MAP or so (or atmosphere , I'm at sea level). RPM's are below 750 or so. You can see this plainly if it doesn't start, but it'll record that though.

If it starts, instantly RPM's are 1200 or so and MAP is maybe 30-40.

SO---For my build I want the spark timing at 60-100 MAP and 750-1000 RPM to beBELOW 5 degrees advanced. I don't want to fight the start and kick it back or make it hard to catch.MAYBE in the 2-3 degree range. I put mine in this range, actually at 1-2 degree.
This is INITIAL startarea to address, on the front and rear spark tables.
I think this, if anybody knows better open for all suggestions and or help. I have give up trying to know very much.

AFTER START--- the engine is running about 1000 RPM, trying to get to steady idle. MAP has droped to 30-50. You want that spark to be higher, in the 15 or soDegree range.
At the 1250 RPM range you can give all a little more across the board, below 50 MAP maybe 18, above 60 MAP maybe 6-8 degree.

The engine is running so start is over.

There are also cranking fuel tables to look at. Book says hard starting mostly not enough,,, BUT if you smell fuel they are settoo much. That is sorta a range I guess.

Now these are just my observations but I have put my START TIMING in these areas andmy engine starts instantly. NOW it does.

Maybe your PC has a starting area you can set more approiately. Lower the timing a little at starting?? Let us know