Evaluate my spark plug color
 

292 with 2100 carb. 4400' elevation. #46 jets. Idle speed is 550. Mix screws are one turn out.
'62 F100 4WD 4spd with 9" rear end 3.89.
Distributor is set for 12° initial advance.
Dual advance:
..Vac starts to add advance at 600rpm.
..Mechanical starts to add advance at 1000rpm.
My advance curve is pretty smooth from 12° at idle to 51° at WOT, in the garage.

All pics are the same plug, after highway cruise at 50mph.

https://cimg1.ibsrv.net/gimg/www.for...31b30b2c97.jpg

https://cimg2.ibsrv.net/gimg/www.for...7f0285821b.jpg

https://cimg3.ibsrv.net/gimg/www.for...ece50895c2.jpg

https://cimg4.ibsrv.net/gimg/www.for...9c320e4e31.jpg


Thanks.

Here you decide. FBO Ignition - Home of the HRR688 - Spark Plug Reading

The way I was taught is that is lean. I was taught tan or chocolate brown color was a good all around burn

.Vac starts to add advance at 600rpm.
..Mechanical starts to add advance at 1000rpm.
My advance curve is pretty smooth from 12° at idle to 51° at WOT, in the garage.

Vacuum advance is a load sensing not RPM sensing it cannot be checked by just reving the engine other than to just confirm it's working. The only way to check it on the engine is with a handheld vacuum pump.
If you are getting 39 degrees of mechanical advance out of that distributer there is something seriously wrong with it.
The ONLY way to check the mechanical adv. on the engine is with a dial back timing light (vacuum disconnected) and increase the RPM in 500 PRM steps making notes, until it stops advancing. The distributer specifications in your shop manual will tell you what it is supposed to be.

Thanks skidoo. My daughter and I did some hwy cruise tests yesterday: cruise at 50, cut engine, pull over, check plug.
There's no need to operate on the lean side of things. I'm going to jet up.
Thanks.

It's hard to edit posts on this board.

I noticed something about America over the last 20 years: the azzholes and stupid people took over.
They've always been battling for prevalence, but lately, they finally won.

I remember posting on bulletin boards in the early 2000's. People were excited about the new ability to tap into knowledge and experience. For the first 5 years, there was no snark.

Then there was snark.

Then spray.

Then the smart people stopped posting, but the stupid people continued to post a lot because the internet gave them a voice where they never had one before.

I'm not just talking about this board. I'm talking about all boards, and SM, etc.

There are some smart people here, don't get me wrong, but there are a lot of stupid azzholes too.

So look dusty boy: I have vac gauges and timing lights and lots of other fun stuff, and I used them, and my truck is great, and I felt like asking a few questions, etc.
Sorry man.

As you get on with the rest of your asinine life, remember this: we will never come face to face, but if we did, your tone would be polite and courteous. I guarantee it.

Thanks everyone. Call your mother if she is still alive. Mine isn't.

Oh, and here's a tip for crop boy:

If you measure the distance from the TDC mark on the balancer wheel to the 10° mark with a caliper, it's 0.546".
Every .546" is ten degrees.
So just make five marks on the wheel with fingernail polish or a paint pen.

Then you can watch your mechanical advance curve, or your combined vac + mechanical advance curve. You can check it at any rpm.
Put a tee in the vac line from carb to dizzy and watch the vac curve too.

You can do this stuff with a 40 year old craftsman timing light and a 50 year old snap on vac gauge. That's what I used.
My timing light is Sears "Best". Not just "Better". I have the "Best" one.
I also had the "Better" version, in a black plastic body, but it quit working after 30 years.


Take it easy crop boy. Keep the BP down, otherwise you'll stroke out.
Find another hobby if you need to.

I don't have a problem. You are the one with the problem. That plug is showing at least 10 degrees too much advance. Keep going until you burn a hole in a piston.

It is not that hard to edit a post YOU posted as there is a "edit" button you click and then edit your post.
It is just that easy.

As for the issue it looks like you have with Crop duster I dont know why :confused:
All he was doing was telling you how the vacuum advance works on your truck in case you did not know.
He is also one of the people that helps the most to the less knowing.

To read plugs you need to do WOT and shut the motor off still at WOT, come to a stop and pull the plugs.
If you let off the throttle it will show it running rich because the throttle was closed and still trying to pull fuel thru carb.
BTW a AFR gauge is the best way to adjust the jets in a carb as it will tell you real world what it is doing.
Dave ----

How much total advance both vacuum and mechanical should a stock 292 distributor have? 64 292?