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Discussion Starter #1
ok about 2 yrs ago i bought a old go cart from a friend in nj , i tested it and the motor ran and we test drove it ect , well i tore it down to rebuild it (it wasn't completed , no brakes and needed paint ect ) . the motor is either a 3 hp or 3.5 hp briggs . i found a crane racing cam for go carts and a ported cylinder head on ebay , so i bought and installed them well the motor has sat in my shop for almost 2 yrs and i wanted to see how it would run , well after a few pulls i decided to check compression and i had hardly any maybe 5 lbs , i used a new head gasket , i think the cam and head were for 5hp briggs but they both fit on the 3.5hp motor fine , what could be causeing the motor to not get any compression ? i was thinking valve springs , i have a set that are supposed to go w/ this cam , but haven't installed them yet , any suggestions are appreciated , thanks
 

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Check and make sure the valves are actually closing when the piston comes up for its compression stroke...
 

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Discussion Starter #3
thanks bugman ,
i was thinking lastnight after posting this that maybe the lobes on the cam are not letting the valves close completely , if this is the case i guess i would grind the valve stems down right ? also bugman what is the best way to check for proper valve clearance ?
 

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check the valves first, maybe the spring is bad, then grind the stem... and b4 grinding the stem try to use the valves that came with the cam =) good luck
 
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