Anyone really good at reading and interpreting spark plug appearance? I have 1988 B2200 with Weber 32/36 DGEV and use NGK BPR5ES spark plugs. Some white on outside of electrode. Thanks.

 

So here is the thing If that spark plug was pulled from an engine that idled down it really is not a way to read spark plug. If anyone say other wise thay have NO VCLUE hoe to properly read a spark plug!!!!!!!

To do what you want and to properly read what is going on with the any spark plug in a gasoline engine....

Cleaned or better new spark plug.
Runt eh engine at the "engine speed? (RPM ) that you are making the adjustment with calibration having to do with jetting and timing.
When you reach that RPM range hold that engine speed for at least 15-20 seconds (more is better) then without adjusting yout throttle TURN OFF the ignition and safely pull to the side of the road , At this point pull any spark plug and take several detailed high resolution picture and try top get clear shoots of the grounding electrode as far down in the insulator as possible.

Then post the pictures.

Also indicate if there is anything you have added to the fuel like cleaners of boosters. These will all effect the readings.

And I say again if anyone claims different form this they have NO CLUE ....about reading a spark plug properly.

And those charts that have been around since the 50"s well the reference to the year should be "NUFF SAID" about that LOL

 

No additives. Truck runs fine.

 

So again what are you asking for by this thread? There you engine may feel like its running fine by your standards but I see some things needing checking and the spark plug condition is not one of them?
What you are asking to have read is what the spark plug is doing at idle speed. The problem is its an old plug with to many miles to be absolutely accurate but you still need to follow a procedure to read them effectively. You may as well install a wide band and get the AFR reading if your intentions is to dial in the carburetor because the picture you are showing will not help to do that. Maybe go re-read my 1st response again?

You might also consider doing a "proper" cylinder compression check. And even possibly followed up by a leak down test?

 

Just wondering, as the only thing I've done with my Weber (since 2005) has been to change the idle jets. My mileage has never been that great, and my tail pipe is black. But the driveability is fine, just B2200 "power".

The spark plugs are 3500 miles old. 3500 miles since the engine was rebuilt, bored to one oversize.

 

What was your reason for doing that?
Unfortunately a first timer to carburetor adjusting no matter what the brand or type is to mess with the idle jets and idle stop set screw before they do accurate spark plug reading, use a vacuum gauge to fine tine the mixture and for advanced users either an exhaust gas or wide band O2 to read the AFR (air Fuel Ratio) before making changes.

If your drivabilty was fine then your MPG should relate to that and your exhaust would not be so rich unless you have other unknown mechanical issues which goes back to my previous responses about doing other health checks on the engine.

 

That plug looks normal to me

 

If you mean changing the idle jets, the answer is to get the correct amount of turns adjustment for the idle mixture and speed. Note that this was 16 years ago.

 

OK well I have no idea where you live but if you live in the USA then 16 years ago the gasoline and the federal mandated mixtures have changes a lot over the years which effects most all carburetor engines.
I will also mention that anything you read having to do with turning the idle mixture screws is mostly to get the engine run and idle after installation or proper idle jetting changes as needed NOT to dial in only method of adjusting and tuning. So who knows where you are at by changing the idle jets as you said?

I suggest again to go back to the beginning of your thread and re-read my responses. Your are not helping me to help you.

I sold in my Performance shop and used most all ORGINAL WEBER products in the 70's and 80's before they went through ownership and corporate changes that effected the quality as well the support of the WEBER Name. Also in my other shop I installed and tuned WEBERS, Holley's, Carters, Thermal Quads and a few other type of carburetors that are more on the rare side.
The sad thing is with the intervention of the internet every tom dick and DIY giving advise you have to weed through the BS and try to find good reliable and fax based information backed by extensive experience and knowledge of carburetor tuning and not someone working on a couple Weber's out of their garage. LOL

 

My questions have been answered, thanks.