FLAMEOUT and the '08 EFI

[Coffee]

I have had my TE310 for a couple of months now and I figured I would throw in my 2 cents worth on the flameout issue and I apologize in advance that this is long. The powerup kit was installed at the dealer and they set it up on the computer and it has ran great from day one. The first time I got the bike in a tight gnarly section I had a couple of flameouts but I attributed that to getting familiar with the bike and it not being broken in. I was also coming off a YZ250F that was basically stock. Since the 310 had so much more torque and a more linear powerband I often found myself in way too high of a gear and would end up stalling. In more open situations the bike ran perfectly with occasional popping on deceleration. I turned up the idle a bit and as I got used to the bike the stalling issues seemed to go away.

So I do the first oil change and head out to work on my clubs enduro. All very slow speed stuff, arrowing, clearing branches, etc. Stop and go all day long in hot and very humid conditions. Well, I had flameouts galore and often times the bike proved very difficult to re-start. At one point the fuel pump would not prime and I turned off the key for a few moments and then was able to re-start after that. This bike was running great before today, what changed? The only thing I did was change the oil.

Later at home I went to check the oil level in the sight glass and realized that I had overfilled it with oil. Not sure by how much but the level was somewhere above the sight glass. Not sure how that happened but there might have been some beer involved Anyway, decided to change the oil again and got the level set correctly between the two marks.

Headed out the following weekend to work on the enduro again. Same slow speed stuff. Same hot and humid conditions. I had noticeably less flameouts on this day. An occasional stall maybe but not nearly as many issues as I had the previous weekend. The bike was starting easier also.

Now I am wondering if the way the head vent tube runs into the intake tube is possibly a contributor to some of these issues. The way I figure is when the oil is extremely hot there will be more hot vapor going straight into the EFI. My, um, experiment with excess oil in the crankcase seems to confirm this as the flameouts were worse when the oil was overfilled. I saw this at Rick Ramsey’s website http://www.rickramsey.net/TE310mods.htm#headvent and I am thinking that I may give it a try to vent the vapor out rather than back into the intake. Anyone have an opinion on this? Do you think it is worth trying? What would be the best way to plug the hole?

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.

 

[LRPct]

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..

 

[jlk_250]

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.

 

[MOTORHEAD]

Now I am wondering if the way the head vent tube runs into the intake tube is possibly a contributor to some of these issues. The way I figure is when the oil is extremely hot there will be more hot vapor going straight into the EFI.

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.

 

[seymore]

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.