Breather tube hose?? By 250cc (Read 3,236 times)

[250cc]

My scooter started to make a strange noise under the seat so I took off the cover (where you adjust the valves on a Honda 250cc clone) and saw that the rubber hose had burned in two and was making a strange noise. It doesn't seem to hurt speed or performace any just makes the noise. It is 5/16 id fuel hose that is on it now. Is these something that is heat resistant that I can put on it?

[Cruiser]

I do have a good picture of that area from the CVT side of the scoot. I don't even see any hoses here:



I believe most hoses in this area could be emissions related although I know that some vacuum hoses are up there and if they were burnt there would be a definite performance hit. A picture of the damage would be a big help.

[250cc]

This will better show what and where my problem is. I am using 5/16' ID fuel line but it is burning in two right where the steel fitting ends.
I have tried differing lengths of hose but it doesn't help. Is there a heat proof hose?

[scootaway]

It looks like the crank breather hose. It comes from the crank has a union with another breather coming out from the tapet cover then go down to the airbox.

[250cc]

What he said. The fitting comes out of what I guess is the valve cover? (It's where I adjusted the valves.) I bought the scooter with 742 miles on it and the hose was bad it looked like it was cut but now I see that it was burned through. I replaced it with 5/16 fuel line hose but it didn't last long. I don't know what type of hose to put on there to keep it from burning through.

[scootaway]

Try a spacer of sort and place it between the hot engine surface and the pipe.

[250cc]

It's not touching the engine. It doesn't burn through on the bottom it burns through on the top. Fuel line is rated 212 degrees
I see that some hydraulic hose is rated at 350 degrees I may try that but I have no idea how hot the air coming out of the engine is.

[250cc]

I got a foot of hydraulic hose to try and Ive ordered some silicone hose that is supposed to withstand 400degree F temperatures. I'll try anything once, well maybe twice since I'm on my second chinese scooter.

[250cc]

UPDATE!!
The hydraulic hose didn't work it burned through just like the fuel line hose. I have put on a piece of blue silicone vacuum hose that is supposed to be good up to 350 degrees. We'll see how that works. ;D ;D

[damin69]

Now that is really weird. What is going through that line that is so hot? I would think all of us with the Honda Clone would be haveing the same issue. something has got to be wrong with where the line hooks up to the motor. I have been so busy trying to trouble shoot my Elec issue I had forgot to take a real close look at this area on my bike when I had all the plastic off this last weekend.

If all is normal you almost need to go look for some metal hose like this stuff.
www.hosexpress.com/metal/316stainless.htm

[250cc]

It is a valve cover vent like where a PCV valve is on your car. It is not a threaded fitting it is a hose fitting, the attached hose tees off and one runs into the air filter box and the other goes back into the engine somewhere near the exhaust. I added the brass fittings hoping to disapate some of the heat and to prevent burn through.

[zugzug]

Why dont ya reroute it so its not going straight accross the valve cover? I can check my 250 this weekend and see how its set up if ya want. It should be a simular type of setup.
-Zug

[250cc]

No way to reroute as the tube is fixed. Mine looked like yours and the hose was burned before it got to the tee. I rode about 25 miles this evening and so far the silicone hose is working. The hydraulic hose lasted no more than 6 miles.

[Alleyoop]

If you can't turn the Brass Nipple on the Valve Cover just put on a longer hose and have it curve away from the Valve cover.
Alleyoop

[250cc]

That is what I did when I fabricated the brass fitting and hose manifold, but the hose still burned through. The hose didn't burn on the bottom next to the valve cover it burned through on top. But I think the silicone hose is going to do the trick.