After I took off the heatsink and put it back on my Ofna Hyper 21,the pullstart became hard to pull. I loosened the glowplug and it's still hard to pull. What else can I ?do

were there any head shims that you forgot to put in?

Was it flooded? did you try taking the plug all the way out?

I took out the glowplug and it was still hard to pull. I did put back all the washers.

Try taking off the heatsink again, pull the pullstart and see if its easier that way, it's possible something got inside there, or something is not seating propely, there should be a pin that lines up the exhaust port with the crankcase, and the sleeve is not seated with the pin lined up.

I put it back the same way the logo was facing the first time and now the pullstart works fine. What was causing the pullstart to be hard to pull?

you got me. Doesn't quite make sense.

I've heard of this before, it's possible the machining was done to match only one way, glad to hear it works now!!!

???? As long as your bolt patter is symetrical theres nothing that would cause it to not seal no matter how it was machined. A circle is still a circle no matter what way the head faces. Do you have a button head or is the cooling head itself what seals the motor?

I'm not really sure what caused this, as I was making a suggestion but, on a waaaayyy older O.S .12 engine with a pullstart did this to me, and to what I remember the cooling head was what sealed the engine, but in cirec's case I'm not sure, I'ts possible that something was not lined up right the first time he put it back on, and it was just coinsidense that it happened that way.