Air Blowing Through The Breather?

KentuckyDonkey · 05-05-2009, 06:51 PM

O-K, guys- while trying to track down why my new Vbike 300 "Monster" (Loncin motor) sounds "clunky" at idle (but great at higher revs), I noticed that there is no filter on the crankcase breather, and that air is continually blowing out of it in a steady pupupupupupupupupupupupup....

Any idears[sic] why this is so? The bike has under 20 miles on it! (And I assume that it was doing this since day one, since the motor has always sounded the same).

warrior91 · 05-05-2009, 10:27 PM

breather gets rid of excess crankcase pressure...normal...
pupupupup...kinda like the same pupupupup of the piston going up and down??? Funny how that is.
If air is blowing out consistently...why need a filter. dust is not going to go into your engine....it is being forced away from the end of the tube...

Some green freaks have a drip resovior so the 1 whole drop of oil residue can go someplace other than the ground ....

KentuckyDonkey · 05-05-2009, 10:34 PM

Ah! Thanks for the info. I kinda thought that the breather allowed air to go in, and that that is why most of them have a filter on the end. I know my other bike doesn't have the air blowing out the hose.....and usually on cars, the bnreather is hooked up to the air cleaner...I figured because it was sucking air in. Guess not.

Thanks.

warrior91 · 05-05-2009, 10:38 PM

no prob...I hope you have some luck diagnosing "clunky "engine....

Not valve clatter???

KentuckyDonkey · 05-05-2009, 10:55 PM

Hehe...the valves are a little noisey too- but I hear that that's normal for these engines (?) especially with a quiet exhaust...??

I should know this stuff- I've rebuilt my share of "real" engines....but these small engines have their differences.

Think what I'll do is take the carb off and do a thorough clean and adjust- as that helped my other bike immensley(even though it also is new and shouldn't have needed it); and I'll change out the Chinese spark plug....

warrior91 · 05-05-2009, 11:23 PM

Chinese plug...LOL

Mabey that is the noise...You could have a flint and steel inside your engine. (doubtfull though, a flint would have more spark than a chinese plug)

KentuckyDonkey · 05-05-2009, 11:45 PM

LOL! Bear in mind, that this is the bike that says "Japanese quality" on the Vbike site. Funny, the old <$1300 V4SW came with an NGK plug....but this $2K bike doesn't (nor did it have greasable zerks as pictured/promised)- for some reason, I think Tim at Vbike sent me all his old crap!

Weldangrind · 05-06-2009, 01:47 AM

I'm sceptical about the validity of NGK plugs in Chinese bikes. Sure, they say NGK, but alot of them are fake. Side by side comparos usually show machining quality and font lettering differences.

05-05-2009, 06:51 PM	#1
KentuckyDonkey Join Date: Feb 2009 Posts: 331	Air Blowing Through The Breather? O-K, guys- while trying to track down why my new Vbike 300 "Monster" (Loncin motor) sounds "clunky" at idle (but great at higher revs), I noticed that there is no filter on the crankcase breather, and that air is continually blowing out of it in a steady pupupupupupupupupupupupup.... Any idears[sic] why this is so? The bike has under 20 miles on it! (And I assume that it was doing this since day one, since the motor has always sounded the same).
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05-05-2009, 10:27 PM	#2
warrior91 Join Date: Nov 2007 Location: N.E. Saskatchewan, Canada Posts: 679	breather gets rid of excess crankcase pressure...normal... pupupupup...kinda like the same pupupupup of the piston going up and down??? Funny how that is. If air is blowing out consistently...why need a filter. dust is not going to go into your engine....it is being forced away from the end of the tube... Some green freaks have a drip resovior so the 1 whole drop of oil residue can go someplace other than the ground .... __________________ '91 Yamaha Warrior- stage 2 '83 Honda ATC 70 '08 Yongjiang 125cc mx (Loncin) '08 Yongjiang 150cc atv (Jinlong)
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05-05-2009, 10:38 PM	#4
warrior91 Join Date: Nov 2007 Location: N.E. Saskatchewan, Canada Posts: 679	no prob...I hope you have some luck diagnosing "clunky "engine.... Not valve clatter??? __________________ '91 Yamaha Warrior- stage 2 '83 Honda ATC 70 '08 Yongjiang 125cc mx (Loncin) '08 Yongjiang 150cc atv (Jinlong)
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05-05-2009, 11:23 PM	#6
warrior91 Join Date: Nov 2007 Location: N.E. Saskatchewan, Canada Posts: 679	Chinese plug...LOL Mabey that is the noise...You could have a flint and steel inside your engine. (doubtfull though, a flint would have more spark than a chinese plug) __________________ '91 Yamaha Warrior- stage 2 '83 Honda ATC 70 '08 Yongjiang 125cc mx (Loncin) '08 Yongjiang 150cc atv (Jinlong)
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05-06-2009, 01:47 AM	#8
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	I'm sceptical about the validity of NGK plugs in Chinese bikes. Sure, they say NGK, but alot of them are fake. Side by side comparos usually show machining quality and font lettering differences. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
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05-05-2009, 10:34 PM	#3
KentuckyDonkey Join Date: Feb 2009 Posts: 331	Ah! Thanks for the info. I kinda thought that the breather allowed air to go in, and that that is why most of them have a filter on the end. I know my other bike doesn't have the air blowing out the hose.....and usually on cars, the bnreather is hooked up to the air cleaner...I figured because it was sucking air in. Guess not. Thanks.
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05-05-2009, 10:55 PM	#5
KentuckyDonkey Join Date: Feb 2009 Posts: 331	Hehe...the valves are a little noisey too- but I hear that that's normal for these engines (?) especially with a quiet exhaust...?? I should know this stuff- I've rebuilt my share of "real" engines....but these small engines have their differences. Think what I'll do is take the carb off and do a thorough clean and adjust- as that helped my other bike immensley(even though it also is new and shouldn't have needed it); and I'll change out the Chinese spark plug....
	0

05-05-2009, 11:45 PM	#7
KentuckyDonkey Join Date: Feb 2009 Posts: 331	LOL! Bear in mind, that this is the bike that says "Japanese quality" on the Vbike site. Funny, the old <$1300 V4SW came with an NGK plug....but this $2K bike doesn't (nor did it have greasable zerks as pictured/promised)- for some reason, I think Tim at Vbike sent me all his old crap!
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