That timing doesn't sound right. I'm thinking you do not have vacuum advance. What is the idle speed? If it has vacuum advance the timing should be about 20 degrees are more at idle, so the vacuum diaphram may be shot or most likely 10inches is not enogh vacuum to advance it, you can test it by hooking a vacuum pump (like the ones used to bleed brakes) to the diaphram and apply about 20 or so inches of vacuum. The Idle should increase significantly. If you can handle a timing light at the same time or have a friend check the timing you should see it increase. If you do not have aa vacuum diaphram consider lighter springs to bring the advance in sooner. I have 10degrees set in to ease starting and a total of 34 degrees all in by 1.5k. But each engine is different. Then you can start tinkering with thw carb, as already been said you may be running on the transition circuit of the carb.