Honda Express compression

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   Hi Lads, I have a 82 NU50 which i have replaced the rings, base gasket and head gasket but have almost no compression. Has only 900 miles on the clock . (but who knows). The piston and cylinder are in perfect shape. I found that while kicking it over there are air pulses coming out of the carb. Any suggestions as to a cause?. Could this be a reed valve problem and if so how do i check the valve. Thanks much for any and all assistance. This is a great site. 

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lamont Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: January/14/2010 Status: Offline Points: 7	Post Options Post Reply Quote lamont Thanks(0) Quote Reply Topic: Honda Express compression Posted: November/27/2011 at 8:26pm
	Hi Lads, I have a 82 NU50 which i have replaced the rings, base gasket and head gasket but have almost no compression. Has only 900 miles on the clock . (but who knows). The piston and cylinder are in perfect shape. I found that while kicking it over there are air pulses coming out of the carb. Any suggestions as to a cause?. Could this be a reed valve problem and if so how do i check the valve. Thanks much for any and all assistance. This is a great site.
	jomama

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donp Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Master Regional Rider Joined: October/27/2003 Status: Offline Points: 8502	Post Options Post Reply Quote donp Thanks(0) Quote Reply Posted: November/27/2011 at 10:33pm
	sounds like a reed. most reeds are just a thin flat piece of metal or some kind of carbon fiber that seals against a rubber base. they are usually located under the intake pipe where it mounts to the engine block. on most 2 strokes if the carb is mounted to the cylinder there will not be a reed. but if the intake passage dumps below the piston skirt, and the intake is mounted to the cylinder, then there will definetly be a reed valve to maintain crankcase pressure on the compression stroke. pull the reed apart and look for any cracks or chips in the rubber base where it seals against the reed. if your engine is a 4 stroke, you have an intake valve that is not sealing. this is usually caused by either crud in the valve seat, a worn seat, or the push rod clearance is too tight. a 2 stroke needs 120 lbs of compression or higher to run correctly. a 4 stroke only needs 75 lbs.
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lamont Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: January/14/2010 Status: Offline Points: 7	Post Options Post Reply Quote lamont Thanks(0) Quote Reply Posted: November/29/2011 at 8:35am
	Donp, Well i removed the carb and the reed. Found a snall piece of crud under a reed and removed it. Cleaned everything up and reinstalled them but still no comp. . New rings, base and head gaskets and cleaned the reed. I give up . I think its going to go down the road before i waste any more money on it.
	jomama

donp Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Master Regional Rider Joined: October/27/2003 Status: Offline Points: 8502	Post Options Post Reply Quote donp Thanks(0) Quote Reply Posted: November/30/2011 at 6:36am
	when you installed the rings, did you by any chance measure the rings end gap in the bore? if you put standard size rings in a .010" over size bore then you will lose compression. doesn't this honda have a compression release valve too? if there is a second brake lever on either side, or some type of extra lever, then it does have a compression release valve that is usually located on the top of the head. this valve may be stuck, or have some crud in it's seat.
	need a manual for your moped? look here; http://www.myspace.com/228297811