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Another possible reason for my rich running

Posted: Sun May 20, 2012 9:43 am
by spandit
Haven't posted on here a while as have had other stuff going on, but did some more work on the Pinz today. It's still running very rough at idle - I can't really get it to run below about 1700rpm. Timing is fine (it's solid state but I checked it with a gun anyway) and I've fitted a potentiometer so I can adjust the timing up and down on the fly. This will help me tune it on the road (I can plug a laptop in and log everything, including marker points).

I digress.

Some of you may recall I had a problem with my idle mixture screws - they were all broken, so I replaced them. Had a look inside the carb barrel today and noticed that it looks like the sidewall has been broken where the screws have been driven in too far (possibly by me, possibly not):

Image

If this isn't the normal state, which I'm guessing it isn't, would this mean that the opening the screws are supposed to seal when screwed in is permanently open and thus letting more fuel through than required, leading to the rich running at idle? At increased RPM the engine sounds quite sweet

Re: Another possible reason for my rich running

Posted: Tue May 22, 2012 11:13 am
by Haf-e
That doesn't look good... most certainly the problem. Surprised it happened with the material of that part of the carb.

So what is the ignition system you are using? Sounds pretty sweet.

Re: Another possible reason for my rich running

Posted: Tue May 22, 2012 11:19 am
by spandit
Megajolt Light Junior - it's a great system & adds vacuum advance to the mechanical advance of the Pinz so gives 3D advance correction. Has a rev limiter built in & can also react according to engine temperature etc.

Re: Another possible reason for my rich running

Posted: Tue May 22, 2012 7:52 pm
by audiocontr
Are they still available anywhere? How much?

Re: Another possible reason for my rich running

Posted: Tue May 22, 2012 11:19 pm
by spandit