okay guys..
ive just been wondering this. when i go start my car sometimes, it starts up, then as its settling down, it runs on one rotor, after about 5 seconds, the second rotor kicks in. since ive been premixing, ive had less trouble with this.
does this mean low compression for sure or could it be something less expensive?

 

How did you diagnose the low compression? Did you get a compression tester and check?

If you didnt, it might not be low comp. When I had the same problem on startup, I used a timing light to find that the rear rotor was not firing. So I checked the spark plugs on the rear. The leading plug had a cracked insulator. This allowed the engine only to run on 1 rotor until it heated up. It ran fine when warm. I changed the plug and the car was able to start.

You should check for spark, fuel, and compression. Dont assume that running on 1 rotor is a compression prob. Check 1st!