How do you change valve seals on carbed 305? j/w ...need to be changed its leaking .....

 

you have to pull the heads and take them to the machine shop to have them rebuilt./

 

You can do it with compressed air to hold the valves up, or a piece of rope stuffed into the cyl. It is not necessary to pull the heads.

Use the "umbrella" type seals. The "positive" type are even better if you can find some for stock outer diameter valve guides.

Rotate the engine to #1 firing; take the #1 rockers off; put the compressed air to the cyl, or stuff it full of rope; compress one of the springs with the spring compressor; remove the keepers, then the retainer and spring; install the seal on the valve stem over the guide; put the spring, retainer, & keepers back on. Do the other spring the same way. Put the rockers back on; tighten their nut until the push rod has no clearance between the lifter and the rocker, then ¾ more. Do both rockers that way. Rotate the engine exactly 90°, which would be #8 firing; lather, rinse, repeat.