I bought a Garelli Gran Sport and I was told that it only had one of the two piston rings in it. I tried to run it anyway and it would run, but only if it was on full throttle all the time. While it was running it would act like it's running rich (it would backfire a lot and could only run if there was nothing blocking the intake like an air filter or the air filter housing). I thought it was just running rich, but I did a compression test anyway and it only had around 73 psi. I will obviously be throwing in another piston ring to get the compression back up. Does it make sense for low compression to cause symptoms that seem like it's running rich?