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Hi all

I am hoping I can get some help with a problem I am having with getting my five year old BG 86 Blower to kick over. It is an early model I believe with the L & H rev adjusters factory set and require some specialist tool I believe. Anyway, here is the issue. It was running but suddenly there was an almighty racket and I immediately stopped it. It turned out that one of the bolts behind the flywheel worked its way out breaking one of the fins and damaging the flywheel by scraping the alloy (pics attached). I removed the flywheel and cleaned away the sheered pieces of steel and replaced the flywheel and dis nothing else but from that point on I can't get it to kick over. I have:

1. checked the air gap between the magneto and the coil and reset it using business card thickness.
2. Grounded the spark plug to check that there is a spark - there is.
3. checked the coil by removing the wiring and still a spark.
4. Cleaned the carburettor and replaced the diaphragm
5. replaced the air filter
6. removed the manifold and checked that there was no hydro-locking or excess fuel
7. Checked the throttle wire
8. Put a bit of fuel into the spark plug opening to see if I could get it to kick over - has compression but will not fire up
9. Sprayed a little brake cleaner in the cylinder (old aircraft mechanics trick) to try and get it to fire, but nothing.

I am at a loss and not being a mechanic makes it worse, but I want to learn and fix this myself.

I did notice that the flywheel key inside the flywheel was sheered (see pic) and I am now wondering if this is somehow causing the problem. There is no movement on the flywheel when I tighten it up though. What does the key do? Is it a part that must be in play for the motor to kick over?

Anyway, appreciate any thoughts on where to go to from here. I recall being told that when there is a problem it is generally one of the following spark, gas or air - is it possible that the cylinder or piston has suffered damage? I cannot hear air when I rotate the flywheel and there seems to be compression.

Thanks in advance for any help.

I found an old BG 86 for parts and exchanged flywheels and finally it kicked over. So the culprit was a broken woodruff key - this "new" flywheel has two snapped fins though - is this an immediate problem? I am assuming that they are essentially for cooling, is that correct? Am I also right in believing that two snapped off fins won't be an immediate major issue?

It may vibrate a bit more.

I am curious if it may cause an off-balance in force in the flywheel and cause it to spin slower or faster than spec which may cause extra wear on particular parts. But just a theory. =)