Cylinder 3 running rich

[thurley94]

Well, it may come as a surprise to y'all, but the valves on 3&4 were tight... Once my shim tool comes in I'll be getting in touch with the shim club! Thanks for the help in troubleshooting!

[LAB3]

A shim tool is good, many people use the "zip tie method" Here's a link that'll give you the basics on how it works. The only thing I would add to what's shown is that zip tie tool is "made" by crimping it with a pair of pliers and once you have the pressure off the shim you can use a magnetized screwdriver to very easily remove the shim. Some would say this also magnetizes the shim and could make it hold metal filings in place, I'll leave that for the Bill Nye fans to debate.

https://youtu.be/DhmGBkje-dY

[Brendan W]

Spark test was good for cylinder 3!

Sparking in the open is one thing. Doing it under pressure is another. You could swap lead #2 and #3 and see if the colour moves with the lead.

[thurley94]

Good tip- I'll try that as well once I get the new shims in!

[superawesome]

Quick check: Does your choke plunger retract all the way? Try to gently push it in with a screwdriver and see if it moves.

I had unstable idle because plunger #3 stayed open a few mm and made the mix way too rich. Did not even fire most of the time.

https://www.thegsresources.com/_forum/showthread.php?254877-that-*-amp-!-choke-plunger&highlight=

EDIT: just saw it is a 1983, and probably has CV carbs (mine has VM). Not sure how it works on those (but I am sure choke can get stuck there as well )...