Stuck Valve

jbcruisin

Active Member
Oct 10, 2008
1,118
6
38
Lebanon, Pa.
My 51 Pacemaker has a brand new engine in it. I started it back in the spring when I put the engine in and did not start it all summer. I tried to start it last week and it would not start. I realized it had no compression. I took the tappet cover off and the exhaust valve was stuck open no. I did not want to disturb the head so I just got a needle nose pliers and played around with it and it popped down and the bike started right up. I must ride my bikes more.
 
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indian22

Well-Known Member
Dec 31, 2014
4,205
5,961
113
Oklahoma
My 51 Pacemaker has a brand new engine in it. I started it back in the spring when I put the engine in and did not start it all summer. I tried to start it last week and it would not start. I realized it had no compression. I took the tappet cover off and the exhaust valve was stuck open no. I did not want to disturb the head so I just got a needle nose pliers and played around with it and it popped down and the bike started right up. I must ride my bikes more.
These motors are so interesting. Is the engine you're reporting on an original Whizzer or a latter Asian clone?

Rick C.
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
201
63
Colonial Coast USA.
Bad fuel is a culprit on stuck valves. As the fuel degrades it forms varnishes which collect on the valve stems. Engine may run ok on the fuel but when it’s shut off the varnish glues the valve open if the cam is in the right position as the engine cools. I first became aware of this when working at a Volvo used parts business. We used an old flat head fork lift to move the cars around. Was running fine one day next wouldn’t start had no compression on two cylinders. Had stuck valves. Turns out one of the guys put old drained fuel from a car in it. After draining the fuel, replacing it with fresh and freeing the valves there were no more issues.