Gunson Colortune Always Yellow

[siteunseen]

Well you said it ran better all the way up so that explains the yellow part. I would make sure the nozzles are completely up. That flat bar Mark spoke of can get out of shape and keep them from reaching their height and lessening the fuel. 

Have you a way to meter the air flow, balance that? These are great and fairly cheap.

Well after googling it there not so cheap anymore?

https://www.amazon.com/Latest-Rage-5385730856-Carburetor-Airflow/dp/B00CMC57R0/ref=pd_aw_fbt_img_2/140-4982961-2615742?pd_rd_w=Xlzjj&pf_rd_p=76328f70-5fff-49b7-869a-94bfdaa768fc&pf_rd_r=JECHWPJ6RGT64TVVHVNZ&pd_rd_r=42368007-404a-49b9-87a3-cbbfc73c54b5&pd_rd_wg=n1J8w&pd_rd_i=B00CMC57R0&psc=1

I agree with Steve and Zed, a good tune 1st. When I got mine the best running ever I had my timing full advance  at 17 at idle then the dial back set on 34. At 2,500 rpm it sits at 0 on my light. BUT! I have a ZX electronic distributor. Love the old car but the simplicity was increased with the newer ZX dizzy. 

[siteunseen]

2 minutes ago, SteveJ said:

That's what @240260280 taught me to do.

Me too!

[HappyZ]

Thanks to all.  Based on all of the advice here's my plan:

• Install electric points and new coil
• Rebuild carbs.  I don't know the current status of the carbs, so rebuild is in order.
• Wrap my headers to reduce temps - I don't have space for a heat shield between the header and the intake manifold.
• Adjust the valves
• Set the timing
• Adjust the carbs - to include balance and Colortune 
• Take her for a spin

I will definitely read the '72 FSM and use as my guide.

[siteunseen]

Thanks to our buddy Hoover here's a good read. Once you wrap your head around this it all falls in place. The "ah ha" for me.

 

[Zed Head]

"Electronic ignition" is what you mean by "electric points".  The points are already electric.  What type will you be installing?  there are many.

Interesting that people suggested 1, 2, 3, 4 and you said okay my plan is 3, 2, 4, 5.  Nothing wrong with doing your own thing, just interesting.  Good luck.

[HappyZ]

@Zed Head I truly appreciate your observation, and I do try to follow the recommendations.  I'm waiting on the carb rebuild kit, so can't do that yet.  I added my rationale (in bold) to each of my points below:

• Install electric points and new coil - I received this the other day, so thought I'd install it.
• Rebuild carbs.  I don't know the current status of the carbs, so rebuild is in order. - I really do think the carbs are part of the problem, so thought it would be good to know it's done right.  I'm not sure when the kit will arrive.
• Wrap my headers to reduce temps - I don't have space for a heat shield between the header and the intake manifold, so I'm concerned that the heat from the header could be an issue.  I don't have any real knowledge in this area it's just a hunch.
• Based on what you guys have recommended, I believe the next three steps are in the correct order...
• Adjust the valves
• Set the timing
• Adjust the carbs - to include balance (with airflow meter) and Colortune.  The pic is a little device I rigged during my MGB days.  The end that contacts the carbs bends to accommodate tight spaces.
• Take her for a spin and adjust as needed.

Edited February 18, 2022 by HappyZ

[Zpenman]

I know you have the choke cables disconnected, but just make sure they aren't sticking closed. Had this happen on my '71, and it drove me crazy.

[240dkw]

What kind of gas are you using? I thought I read somewhere that the colortune does not work with ethanol gas.

[Yarb]

This post is over 2 years old.

[Zpenman]

Thanks, Yarb. I saw the Feb date but not the year. lol