M38a1 running problem...brown smoke? With video

linx310 · Post by **linx310** » Tue Apr 15, 2014 9:05 am

After cleaning up my carb and attempting to get the float setting correct on my M38a1 I managed to get it to idle decently but when I blip the throttle it hesitates and then spits out a cloud of what looks like brown smoke.

http://www.youtube.com/watch?v=2G9kpU9h2GU

Now it could just be my eyes and the cloud is actually black but I am not sure.

BullRun · Post by **BullRun** » Wed Apr 16, 2014 10:52 am

It does look brown! I am thinking it is rust from your exhaust system.

Post by **wesk** » Wed Apr 16, 2014 2:04 pm

Generally the hesitation will be one of two causes.

1-Accelerator pump diaphragm bad or housing leaking.

2-Centrifugal (governor) advance stuck in distributor.

3-In some cases a too lean idle mixture will mimic the accelerator pump problem.