I have an 81 GSL that has the motor from an 83 GSL, still 12A, with a rebuilt (by my dad and I, so probably still not perfect) nikki carb. When we try to start, cold, it takes it a minute, you can hear and feel it getting faster and faster(like its winding up) until it finally hits and starts. Our method of starting is turn the switch on for a few, three pumps of the gas, and pull out the choke, at the moment that's the best way we've found. It takes 5 -10 minutes to warm up and idle about 900-1100 rpm. after it gets to idle, if you ease the gas it goes up fine, but if you stomp it there is a pretty noticable hesitation. Just installed new NGK plugs today and it does the same thing. If you try to start it hot, you can hear it getting faster, and when you think you got it, it drops back down and then you just have to wait for it to cool off. other than messing with the timing some more, i'm at a loss. thanks.

 

Do a compression test on the engine. The procedure to do this is in the archive section.

 

Did the test, number one was around 30psi, two was around 60psi. Granted, the engine was sitting for 4-5 years before the transplant, and we've only had it running the past two weeks. We did the seafoam treatment to it. Also, we removed the rats nest, and I'm quite certain that there are hoses that aren't in the right place, or things not plugged. are there any other diagnoses for the hard to start problem. If we set the idle higher, the hesitation seems to go away some.

 

30 is a very weak #, 60 isn't much better. 80 is generally consdered time for a rebuild. Pour a capful of motor oil down each barrel of the carb and see if starting improves. If it does, then it's more than likely time for a rebuild.

Are your #s cumulative, i.e., you didn't release the schrader valve and the 30/60 psi is the highest reading you can get from each rotor? If that's the case, then either your seals a sticking badly or the engine is worn out.