Pulled the carbs back of for a better cleaning and noticed this.



So not quite sure what I should do to attack this problem. I just cleand the airbox three weeks ago or so and this much stuff has allready worked its way up the tube. And is headed strait into the carbs. Im assuming its the same stuff all over the valves. Is there something that would cause this vent tube to belch out gunk. And is there something I can use to clean the valves to just break the stuff up and let the motor just ingest it. (I know this is not ideal but I really dont want to rebuild it yet.)

 

That hose is attached to the cylinder head cover and is used to vent vapors from the engine case. It's part of emissions. Unless you going to pull the cover to clean that, there is not much you can do about it. As for the valves, anything you spray down there to try to clean them is going to end up inside the cylinders. I don't know that I'd be terribly concerned about the intake valves. If it's strong enough to clean that stuff off the valve heads, it's certainly strong enough to wash the oil off the cylinders and piston rings. I think you could cause more damage than good.

If you really want to clean them off, try a rag on the end of a screwdriver with some solvent on it, or maybe a coat hanger. Anything that gets in there should be either vacuumed out or blown out with an air hose/compressor. I would not advise allowing it to get into the cylinders.

Have you adjusted the valves on the bike, or at least checked them ? If not, while you've got the carburetors off, now would be a good time. It will also give you the opportunity to clean the cylinder head cover (the source of the gunge). I don't know how many miles are on your bike so it's hard to say whats normal or not. It's possible that the PO didn't maintain the bike very well and there's extra "gunge" that wouldn't be there if proper maintenance had been done all along. The key to preventing that gunge is changing the oil at the recommended intervals, new oil filters and air filters.

I'm not sure if any of this is helpful, but these are my thoughts based on what I see.

 

did you end up doing anything about the build up on your intake valves? I was in the middle of a valve adjustment and ended up discovering that there is build up on one of my intake valves that is stopping it from closing properly. I'm wondering if pulling the head is the only option for getting the valves cleaned up?

 

I still have not had time to get to that. Right now im waiting on some shims. This has taken me longer than I had hoped. Just haven't had the time. I just re read what idodirt had written me when i posted this and im with him in thinking that if its strong enough of a solvent to eat that stuff and that it will get in the cylinders and possibly cause serious damage by removing oil. As far as a valve not closing because of this stuff I dont know what to tell you. (other than removing the head) Hopefully IDODIRT will read this and send some wisdom your way. As for me the new supermoto that is about to go in the shed might trump the ol f3 for a little but I still cant wait to get her going again.