Time for rebuild??

[motosportz mike]

Your loose battery cable could have been the cause of the poor running you were experiencing.

 

[Wade n NC]

50 mile ride today. No misfires. Pulled air filter. Oil has collected in intake plenum again but not enough to drip from airbox yet. Loose battery connection most likely culprit in misfires? I felt up where the breather hose comes into the plenum. No oil up there. I don't think that's the source of the oil.

 

[Xcuvator]

Just a thought, but you could put breather filter on the hose and get it out of the airbox. That way you could eliminate it as a source.

 

[Wade n NC]

Something picked up from an auto parts store?

 

[J.R.]

Yup, mini K&N style filters about 1-2" tall.

But what I wonder, does the line coming from the valve cover ever have any negative pressure to suck back in? If its purely positive venting pressure, could you run the line straight up/towards the top of the frame and put the mini filter there?

 

[Wade n NC]

Good question. I think due to a certain amount of combustion gas blowby always being present, there would be positive pressure on the crankcase in all situations.

I'm still trying to figure out how oil would go the opposite way past the rings and end up travelling against incoming air flow to end up in my intake plenum.

Baffled in NC.

 

[Slowpoke]

The oil in your air boot is most definitely getting there via the breather hose.

The blowby gases vaporize a small amount of oil from the cylinder wall and then carry it up the cam chain gallery and/or various oil drain galleries under positive pressure, across the cylinder head to the outlet for the breather hose, then down the breather hose to the air boot. Some of the vaporized oil then condenses on the sides of the air boot because it's a lot cooler in there. Also, some of the vaporized oil is sucked thru the intake and burned in the combustion chamber. The oil that condenses on the airboot sides will gradually run down and collect in the low spot at the bottom of the boot.

Sometimes when these Huskies are dropped on their right side, a few table spoonfuls of raw oil will get into the breather hose and run down into the boot when the bike is picked up.

Looks like your next course could be to do a full leakdown test to see what kind of shape those rings are in, or a teardown.

 

[Dirtdame]

Sometimes when these Huskies are dropped on their right side, a few table spoonfuls of raw oil will get into the breather hose and run down into the boot when the bike is picked up.

I've dropped my bike so that the top end of the machine was pointing downhill and it took a while to get it back on it's tires. This has happened a couple of times. Each time, the bike lost nearly a pint of oil and was very difficult to start, plus it it smoked like an incinerator and misfired for about five minutes trying to digest all the oil that got in the airbox, through the element and into the intake boot. Oil ran all over the shock and down the swingarm. What a mess. Husqvarna should incorporate some sort of reed valve system in the venting like some of the Japanese bikes have.

 

[Wade n NC]

Do you think a 1/2 teaspoonful, maybe more, would collect in a 50 mile ride?

I suppose thought that if the loose battery connection was causing the misfires, and the oil collects slow enough that I won't see any dripping from the airbox for a while, that I have nothing else to complain about. All that remains is to do is check the condition of my motor to see if a rebuild is warranted.

 

[Planepower]

Just a bit off-topic.....
where do you find a 530 kit?

 

[Wade n NC]

I think Motosportz sells one.

 

[Planepower]

I think Motosportz sells one.

Thanks - ill be sure to contact them when my time comes.

 

[Slowpoke]

I've dropped my bike so that the top end of the machine was pointing downhill and it took a while to get it back on it's tires. This has happened a couple of times. Each time, the bike lost nearly a pint of oil and was very difficult to start, plus it it smoked like an incinerator and misfired for about five minutes trying to digest all the oil that got in the airbox, through the element and into the intake boot. Oil ran all over the shock and down the swingarm. What a mess. Husqvarna should incorporate some sort of reed valve system in the venting like some of the Japanese bikes have.

Been there, also.......

 

[pvduke]

positive crankcase pressure is a result of a couple things. oil in the boot is normal. harder ya rip, the more it condenses there as there is no seperator/collector/return line (like a DR-Z 400 etc. has).

i dont like road-drafting the breather, it's nice to keep negative pressure in cases. k/n mini-filters clogg. this causes pressure on rings. open tubes let water/dirt in.

if you have excessive blow-by yer bike will smoke and use oil. just keep an eye on it and swab it when ya do the filter or change the oil. you might be able to fab an inline catch-can to collect same.

pull yer tank and header. take a peek at the guides, down the plug hole and check things out. if stuff is dry etc, then it's your call on the teardown. stuff does wear out over time, incl the bottom end!

 

[J.R.]

So would it be a better idea to fab up a setup like the drz? Then run the drain line back into the cases somewhere? Would that keep the negative pressure? Or am I off track here?