Something wierd is happening with my sporty. I am having oil coming up and out of my aircleaner. Very disconcerting. Also, when it is cold, I can get the damn thing up over 60. Nice weather, no problem, goes like a bat out of hell. Yesterday I was out and riding it for about 30 minutes at 65-70, that is when it was blowing oil all over the right side of the bike. I did notice a little flap controlled by a servo inside the aircleaner box. It is not functioning right. It appears to be related to allowing air inside. After screwing around I figured out that if I pressed the servo up after I energized the electrical system and turned the kill switch to "run", the flap would stay open. This all smacks of emissions control. I want to get rid of it because I think this is the stem of my problems. As for the oil all over the place...could it be related to the oil filter? I read in American Iron a month or so ago that the twin cam filter cures blowby. Anyone heard of that? Either way, this crap has to stop. I want to strip all of the emmisions crap off and I have to stop the blowby. HELP!
The problem has to do with the flapper valve in the heads, pressure is building up and oil is coming out of the breather valve connected through the air cleaner, but thats just my guess, It has to do with the "breather gear" timing, its a plastic piece in your engine the always fails. there is also a "catch can you can install as a fix. you may want to PM FASTSPORTY, he seens to know a thing or two about sportsters.
I read that in American Iron sometime. I'll be pissed if I have to pop the heads. I am hoping fastsporty will see this and hook me up with some advice.
It's a pretty common problem with a lot of newer harleys. Most of the harley boards have a few threads about it. Here's a thread about sportys. There's a couple of links to possible fixes in there.
This is a common problem (accurance) when you have made mods to the jetting size, or carb. If your motor is stock, then I would look toward the flapper valve and see the explanation of preasure build up. Go to www.sportster.org and they have a tech page that explains it all in very complete detail. I have a big jet kit on my evo, and it spurts out some oil when run hard. Not a problem unless you are talking about major amounts of oil.
Gee, I guess my ears were burning, as far as the oil blowby is concerned, on late models. I would first replace the umbrella vavles, yours are 15 years old and that rubber is pretty thin.If the bike sat for any length of time the can dry out and curl. its not that hard to replace just need a torque wrench and about 2 hrs. plus a new set of vavle cover gaskets. Also make sure your oil tank is not over filled. Riding style also makes a difference,riding full throtlle and slamming the throttle to idle pos. will create instant blow by, (but we all do it) my soloution is get some 90 degree breathers and go up towards the tank connect them with a 'T' and run a tube to a small catch can to the back of the bike. don't seal it tight your heads still need to breath, but it keeps the oil off of your tires. As far as emmisions go, the only thing you need to keep is your VOES switch. The other stuff is secondary. Abe- only big twins have that plastic primary breather gear. FS If you have any more Q's just PM me
The TwinCam filter just filters better and the bypass is a better design(less prone to sticking for no reason). put the Screamin Beagle filter assembly on it and that takes care of the emissions BS. You can get the cross over tube and run a line out to the bottom of the bike, you'll never notice it again. The reason could be that your umbrella valve is deteriorated and a new one can fix that. Just take the top off the rocker box and it's a black cicle of rubber up in the corner nearest the carb pull out and replace(this is about the cheapest thing to check first). You can pull the gearcase cover and breather timing and endplay but thats probably not the problem. -Jesse
[ QUOTE ] the only thing you need to keep is your VOES switch [/ QUOTE ] Is that the little fucker that opens the vent into the airbox from behind?
VOES (vacuum operated electronic switch) mounted under the tank has a vacuum line to the carb and a couple wires out the back. It basicly helps to adjust the timing per the amount of vacuum created out of the carb. your bike isn't fuel injected is it? then you would have a MAPP sensor instead of a voes switch. I don't work too much on late model stuff with smog shit. my recomendation is to get a manual, they are indespencible (sp) for shit like this. FS
A VOES turns on the advane or turns it off, it does this based on the vacum of the engine. I know that on big twins it plugs into the manifold itself but is just up under the tank on XL's. -Jesse
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