Mark...
Forum Master
Geely JT50QT-18, '86 yama razz, '84 Honda Spree
Posts: 109
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Post by Mark... on Aug 23, 2006 9:06:03 GMT
Yea, that was uncalled for Ill check on it and see if I can help you figure it out
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Mark...
Forum Master
Geely JT50QT-18, '86 yama razz, '84 Honda Spree
Posts: 109
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Post by Mark... on Aug 29, 2006 19:02:55 GMT
Okay, the crankcase breathes through the camcover and through the oil passages(large opening where chain passes through) on the 4-stroke engine. The only other breather I can figure you are talking about may be the gearbox vent.??
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Post by civvy on Aug 30, 2006 9:44:26 GMT
For performance, Crankcase and Camcase would have a vacuum either by a pump to a catch can/ the elements or a tap into the exhaust. Manufacturers use the intake as a vacuum at the cost of hot oily sludgy air going into the combustion cycle - not good. but they do it because the engine produces less emissions from recycling the sludgy oil.
R.e using the pipe as an expansion chamber won't do its job as an oil/water seperater and once the blow by has passed the rings, where is its relief?
I would prefer to leave both breathers open to the elements when considering how small these engines are.
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mii
Forum Master
Posts: 65
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Post by mii on Aug 31, 2006 9:47:22 GMT
Hmm..they do reroute the excessive oil (and what water? If there is water in there, you can say bye bye to your bearings and soon after that, crankshaft too!) back to the carb for extra lubrication. It has nothing to do with emissions, at least on bigger engines (and even smaller ones too, check how r/c 4strokes work and WHY they recycle the breather back to the carb. It's LUBRICATION, not emission related, no matter how much you wish to believe otherwise).
If the breather is open, it will let water in and oil out. No point letting the engine do that, that's why I'm still going to keep my "breather" closed. STILL I'm saying, IF it did go back to the carb, I might let it be open..don't even know if my scooter has one, but I will as soon as my parts arrive.
I proposed the pipe is acting like expansionchamber..that's not because of the excessive oil or what you believe is water, but because of the pressure. Every time piston comes down, the crankcase will have highpressure (that's why 4strokes have a crankcasebreather, engine might blow because of the pressure build-up if there wasn't one), when piston goes up, the pressure goes down. That's why it needs either breather or expansionchamber, metall does not expand that well, as we all know.
But, the last part of this post is just guessing. Hopefully I get my parts soon, can't really bare to wait to hear her run again.
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Mark...
Forum Master
Geely JT50QT-18, '86 yama razz, '84 Honda Spree
Posts: 109
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Post by Mark... on Aug 31, 2006 10:39:20 GMT
they do not "route" engine oil into the carburetor on any gas engines at all. The only oil going into the carb is on two strokers and that is only specificly 2stroke oil!!!!!!!!!!!
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Mark...
Forum Master
Geely JT50QT-18, '86 yama razz, '84 Honda Spree
Posts: 109
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Post by Mark... on Aug 31, 2006 10:42:28 GMT
also, gas engines that have the crankcase breather connected to the air cleaner have a small filter to keep the oil out of the carb. Theres no guessing.
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mii
Forum Master
Posts: 65
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Post by mii on Aug 31, 2006 11:09:42 GMT
also, gas engines that have the crankcase breather connected to the air cleaner have a small filter to keep the oil out of the carb. Theres no guessing. They indeed do have a filter, but not to filter the oil out. I'm guessing, since I don't know how THIS 50cc engine was engineered. By the way you post, you don't know either, so how 'bout you go and grow some pubic hair and come back, when you can talk like adults do? Looking you ego tripping, might take a while
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mii
Forum Master
Posts: 65
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Post by mii on Aug 31, 2006 11:19:35 GMT
www.polog40.co.uk/maintenance/oilbreather.htmlYou are right about the way it works. Unfortunately, so am I: www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXLHT4&P=0Different desing? Not quite. Both are 4 strokes, the enduser is quite different. My knowledge comes mostly from glowengines, so it's obvious I might make mistakes. Still, you acting up like GOD itself, bitching up to people who don't know things, like those people are STUPID and eventually "giving up"..could you please SHOW ME the breather from your scooter? Does it actually have one?
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Post by civvy on Aug 31, 2006 12:03:22 GMT
Thats right, the connection from the crankcase to the carb or inlet maniflod has a filter and is usually called the PCV filter - Positive crancase ventilation. Breathing systems are designed to let parts of the engine Breathe like a vent. If you had oil coming from there you would be having serious issues. By not removing the bung you are not letting the crankcase breathe!
- John
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Post by Scootin on Aug 31, 2006 12:46:01 GMT
OK Mark & Mii
You BOTH need to be civil. Regardless of who cast the first stone, This space is meant for intelligent discussion of technical matters. ANY further shots at each other & I will lock this thread.
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mii
Forum Master
Posts: 65
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Post by mii on Aug 31, 2006 13:24:38 GMT
dear scootin, I couldn't agree more. I've just seen too many of these forum psychos, following people from thread to another making no sense at all, harrassing and making each others life miserable. Pardon me for being one for a moment, if you will Mark, we shall continue where we were before this little incident?
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mii
Forum Master
Posts: 65
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Post by mii on Aug 31, 2006 13:34:21 GMT
Thats right, the connection from the crankcase to the carb or inlet maniflod has a filter and is usually called the PCV filter - Positive crancase ventilation. Breathing systems are designed to let parts of the engine Breathe like a vent. If you had oil coming from there you would be having serious issues. By not removing the bung you are not letting the crankcase breathe! - John But that's the problem. If it's open, It's letting water in and oil out, since there is no filtering. That's why I've been keen to see it connected to the carb or just about anything that can filter the air in and out. If it's not connected to anywhere, I wouldn't cut it open..causes more problems than it solves.
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Post by Scootin on Aug 31, 2006 14:01:51 GMT
Thats the spirit, Hopefully someone has THE right answer to the restrictor question.
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Post by civvy on Aug 31, 2006 15:57:49 GMT
Ok, If you would care to learn more about Positive crankcase ventilation - aswell as a filter there's also a valve called the PCV Valve! This is a one way valve like the ones found on fish tank pumps and the vacuum from the intake opens the valve and draws hot, oily air from the crankcase into the cylinder. - not good. and again its for emmision reasons.
The reason we have a water seperater on an engine is because when the engine is switched off moisture forms condensation particurly in the rocker cover.
It would be unlikley water would be able to enter the breather pipe because air is coming out when the engine is under load and there's blow-by the rings.
It would be even more unlikely to get oil from the pipe and as i've said its a performance modification to have a vacuum to the PCV circuit.
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Post by Macrofeet on Aug 31, 2006 16:00:34 GMT
okay not sure which bung this is all about
There are 2 possilbe bungs i can picture
1st a bung which is not a bung but is infact a pipe joiner
2nd bung which is what i am assuming this is about
located sticking out of pipe connecting to crankcase
This does nothing there is a link to a guide of how to seal this better which hyper posted about 8 months ago
the crankcase on the 125's dont have same set up just a small fat pipe with filter so wouldent worry about it on the 50cc its not going to be worth while you'd be better off taking the side stand off to try and get extra speed
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mii
Forum Master
Posts: 65
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Post by mii on Aug 31, 2006 16:37:06 GMT
It would be unlikley water would be able to enter the breather pipe because air is coming out when the engine is under load and there's blow-by the rings. It would be even more unlikely to get oil from the pipe and as i've said its a performance modification to have a vacuum to the PCV circuit. Yeah, but then again, I'm quite sure you won't find pcv valve out there, why would it be shut if there was one? To make the crankcase explode under the pressure? Does not sound reasonable to me - if there was indeed enough pressure to build-up, the CLOSED PIPE itself would have exploded away the first day you got it, don't you think? Nope, I'm just not buying this, sorry
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Post by daddyeby on Sept 12, 2006 3:15:28 GMT
YOu both are right and wrong but if you block that line the blow by around the rings goes to the crank case then up the cam chain passage and out the valve cover vent if it is blocked totally and there happens to be no other way out it will blow a seal or gasket somewhere. On older cars the was a just a small filter to catch any splashing oil in the valve cover before venting then later car the fumes whent though a pvc valve then was sent to the breather to a small filter that was replace at reg. intervals then into the carb to be burned to reduce pollution. when the pcv valve was bad it did cause idel problems I have not seen the bung that is shown in the picture in person so I can not tell if it is a small pcv valve but I would not under any circumstance block that vent line what little oil that would normally blow out that line would not be a harm seeing how it is from the top of the valve cover now if it was blocked it could build up if blocked then be released but that vent on my scooter is routed to my intake with out a pcv valve. that is my thoughts and what I know take it for what it worth or not.
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Post by therapistofanal on Sept 13, 2006 15:03:46 GMT
this engine was engineered at 80's. You guys will never find restriction on this one.
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