If you are trying a 3 minute experiment to see if there is a causal relationship between an over filled crank case with vent tube connected normal from the factory vs disconnected and with a filter on it then almost anything would work to plug the hole in the airbox, even plastic grocery with rubber band and duct tape. This is the first post I've read suggesting the may be a relationship. My wild guess would be there is something else going on when the oil level is too high.
Since you brought it up.... I've said on here many times I've never experienced flameouts with my big ole FI 610, even in tight NE woods. I too routed that breather hose as R.R. has shown. Just covered the hole with some duct tape that I always check when I clean my filter. This is my first four stroke also and my first bike in about 15years or so, so it's not like I'm used to lugging a four stroke in the woods either. guess I'm just one of the lucky ones or maybe George blessed it for me when he did my first service for me.. I truely feel for those that have these problems though..The "no muss no fuss" is one of the reasons I went with the FI Husky..
I have a FI-related question for other 510 owners. How low in the RPM range can you lug it and not have it buck? My bike tends to like the RPM >4000 before it's completely smooth and with work on the PCIII I've got it pretty smooth down to 3000 RPM or so. Is that good or should it pull right from idle (which I have at about 1800 RPM)? I'm not talking about pulling hard, just pulling at all. FI may be a PITA in some ways but so are carbs, especially on multi-cylinder engines.
I've had mine plugged and a filter on the hose since the beginning. But, you are right, there's a lot of oil that comes out of there, even when the level is correct to low. Five miles at > 5 grand will get you drool out the vent. Tip over to the right while it's running and you get a lot.
I was talking to the service manager at Moto Tech about TE 08 flame-out issues and he told about a customer with Husaberg that had the same issues. After going through all the EFI diagnostic and finding nothing, a call to the factory informed them the likely cause was low octane fuel. They recommended fuel greater than 95 octane. The customer used a octane booster to get 96 and called back 2 weeks later to say he hadn't anymore flame-out stalls. I would be interested in have someone that experiences flame-outs often to try using 96 octane fuel to see what influence it has on the problem.
