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Author Topic:   no compression
Dirt Roller

Total posts: 15
posted July 11, 2005 09:29 PM  
i ran a compression check on my motor and found number 8 had 0.aired up the cylinder and air came out the carb with both valves closed what does this mean?the motor only has 4 nights on it.

Dirt Maniac

Total posts: 176
posted July 11, 2005 10:32 PM  
Bad valve and/or valve seat. Gunna have to pull the head off.

Dirt Forum Champ
Total posts: 570
posted July 12, 2005 03:51 PM  
The valve seals against the head so I would guess you burned a valve. I would look at the fuel coming in, do you have big enough jets in the carb? better to be running rich than lean. you can adjust rich, lean means tear down.

Dirt Roller

Total posts: 15
posted July 12, 2005 09:54 PM  
the plugs showed it was running plenty rich. lol we pulled the head and found a bent valve.what would cause that? there was a line in the piston but not to was an intake valve and it was bent down towards the piston

sc1 racing
Dirt Freak

Total posts: 419
posted July 12, 2005 10:13 PM  
you want to check your rod bearings. you may have had a bearing problem and caused piston to contact valves, and if piston hit you really want to check bearings..exspecially if they are stock soft bearings..

Dirt Roller

Total posts: 15
posted July 12, 2005 10:16 PM  
thanks everybody.

Dirt Full Roller

Total posts: 30
posted July 12, 2005 10:22 PM  
Sounds to me like you floated the valves. Stiffer valvesprings are in order!!


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