Short Answer: Try a different outlet. Our new instructions will read 85 gram capacity, just to make sure we are under-promising a little. The fact is all units we test roast 90-100 grams of standard size and weight washed coffee. (You have to make adjustments for some other processes and varieties of green coffee though! They don't all spin the same.) The most important thing is to weight every batch, and make sure the coffee is turning in the roast chamber from the start of the roast. See this video example. Some people have older homes that don't truly rate 120v at the outlet. Others have another load on the same line drawing power, or more obvious issues, like roasting with an extension cord .(Don't!). If you cannot test your line voltage (and the voltage drop that occurs when you use the roaster) then try to find an outlet closest to your electric fuse panel and test the machine there. Or try the machine at a friends house, especially if yours is older construction or has modified or converted electric service. Popper is 1200 watts and needs a good electric supply to work at it's best. Another issue here might be in the interpretation of what a good initial rotation of the coffee should look like. If the coffee is moving slowly for the first 30 seconds and gains speed, that is normal. You definitely want to weigh EVERY batch and be consistent, and use a batch size that does result in increased motion of the coffee over the first 30 seconds, If your coffee isn't spinning at all after 30 seconds, you should stop the roast and remove some! But slower initial rotation is totally fine. Check out our video on this! In any case, we haven't seen a roaster that is said to roast only 80% of its capacity that is an actual machine defect - so far they have all been something with the environment they are used in.