OC-3 IXB3 tune up help needed

[Harburmaster]

I live in Hebron Connecticut and need some help tuning up my OC-3 to get it running better.  The IXB3 has been recently rebuilt, but it's hard to start and doesn't have much power.  The compression on it is great.  I have a NOS magneto, new wires and plugs.  I cleaned the carburetor, but know little about it.
If you have the expertise that I need, please contact me as soon as possible.
Thanks

[Robert Barbour]

Check fuel supply, pluged line or dirt in tank, Is the timing right? How good a spark do you have? Even with a NOS mag, you could have a weak condenser and that would cause hard starting and poor power. Would need more information to make furthur suggestions!

[Harburmaster]

I have plenty of fuel and the line and filter are running well, although there may be a problem with the carb.
I don't know how to check the spark, but I have one.
The timing might be ok, but again I'm not sure.
This is why I was hoping for a local person to help me out.  I'm not positive about any part of the system so I can't narrow the search and find the problem.
Thanks for the response.
Dave

[Robert Barbour]

For checking spark, the old style flash tube type timing lights are good. They connect in series with the spark plug.  If you lack experience, put it on a good running engine to see how bright the flash should be then put it on your OC 3  and see if it produces a the same bright flash.  That will give you a starting point, if the spart is good then you will need to check the timing.