Spark plugs?

[bud45]

Got a '69 GMC with a '65 285 installed...it came with Autolite R43 plugs which stayed fouled all the time...went to R45, which lasted a little longer...went to R46SX plugs which I believe are hotter and do last about 6 months.

Well, I wasn't near my usual auto parts supplier, so I went to another on a short trip & got the Champion equivalant to the R45...the counterman said the Autolite plugs weren't right & these would be right..RJ8YC, I think...anyway, they did just like the R45 plugs did- lasted about 3 weeks, so I got some more R46SX plugs & installed them this afternoon. When I pulled the Champions out , theye were still wet & smelled of gas, even though it had been more than 24 hours since I had driven it. When I compared them to the R45 plugs, the tips were the same...the R46SX plugs' tips were extended a little more, telling me they're a little hotter plug- or am I wrong??? Still have a little hesitation & some skips at low speed, but it's better.

I have recently gone over the entire ignition system with Blue Point parts & the shaft in the distributor is good & solid, no side-to-sode travel. I have the carb leaned out almost to the point where the screws are about to fall out, but I suspect I may have to replace it with a new carb, as well as a new fuel pump....

Ideas? Are there any hotter plugs I can go with now, until I redo the fuel system? The countermen at the parts houses I frequent are not like the parts men of old, who knew things like heat ranges & upgrades/changes.

FYI, I ran four heat ranges over in my bone-stock Dodge 440 with the old wide block 318 and it ran clean....

[airdale94]

You can't correct it with a hotter plug if it's dumping that much gas. It sounds like you have carb. troubles. Hotter and colder plugs are really only for minor variances in engines. If everything is good, on stock engine you won't see much differance in changing plug ranges.

[nplocoman]

explain the part were you said having the screw about to fall out. Are you talking about the idle screws?

[jhow66]

Originally Posted by bud45

Got a '69 GMC with a '65 285 installed...it came with Autolite R43 plugs which stayed fouled all the time...went to R45, which lasted a little longer...went to R46SX plugs which I believe are hotter and do last about 6 months.

Well, I wasn't near my usual auto parts supplier, so I went to another on a short trip & got the Champion equivalant to the R45...the counterman said the Autolite plugs weren't right & these would be right..RJ8YC, I think...anyway, they did just like the R45 plugs did- lasted about 3 weeks, so I got some more R46SX plugs & installed them this afternoon. When I pulled the Champions out , theye were still wet & smelled of gas, even though it had been more than 24 hours since I had driven it. When I compared them to the R45 plugs, the tips were the same...the R46SX plugs' tips were extended a little more, telling me they're a little hotter plug- or am I wrong??? Still have a little hesitation & some skips at low speed, but it's better.

I have recently gone over the entire ignition system with Blue Point parts & the shaft in the distributor is good & solid, no side-to-sode travel. I have the carb leaned out almost to the point where the screws are about to fall out, but I suspect I may have to replace it with a new carb, as well as a new fuel pump....

Ideas? Are there any hotter plugs I can go with now, until I redo the fuel system? The countermen at the parts houses I frequent are not like the parts men of old, who knew things like heat ranges & upgrades/changes.

FYI, I ran four heat ranges over in my bone-stock Dodge 440 with the old wide block 318 and it ran clean....

No way are you leaning out your carb if the screws are about to fall out. No wonder you cannot keep plugs in it Out on the idle mixture screws richens the mixture. What kind of carb? V8 or 6? 285?

[nplocoman]

Originally Posted by jhow66

No way are you leaning out your carb if the screws are about to fall out. No wonder you cannot keep plugs in it Out on the idle mixture screws richens the mixture. What kind of carb? V8 or 6? 285?

[GREASEMONKEY72]

try putting the screws all the way in and back them out about 3 turns and see what happens

[nplocoman]

One more time, I agree!!!!!!!!

[ChevLoRay]

Just be careful when you screw them in, and don't bottom them out. If you do, or if it has already happened, they will have grooves cut into them which will make setting the idle a bit tougher. Back in the day, I used to build them, then when setting them at first, screw them in and back 'em out two turns to start with.

[piecesparts]

You could use a vacuum gauge to get the idle mixture screws set to their optimum setting, or you could do it by idle sound---your choice. The vacuum gauge will set the idle screws where they are at the point that they do what is the absolute best they can do.

This is done by connecting a vacuum gauge to the intake manifold source (such as a fitting just behind the carb. Then set your idle speed to a good setting like 700 RPM), and now note the vacuum reading. Next, turn the first idle screw inward until the idle drops off a little--and then turn the screw outward until the idle speed stops increasing and further adjustments out will not make it get any better (look for that point carefully). Now turn the other adjusting screw inward until the idle drops off and then adjust outward until the idle is no longer affected, just like the first screw. Now readjust the idle speed to 700 RPMs again. You will want to do the idle screw adjustment of the idle screws one more time to make sure that you have the mix adjustment at the OPTIMUM setting. ONCE you have found the sweet spot on the screws, TURN THEM INWARD an 1/8th of a turn and you are set.

Keep in mind if you are getting large amounts of fuel on your plugs, that the idle mixture screw are only affecting this when you are in the idle/air circuit, not the power mode of the carb. There very well could be a carb rebuild in your future, as it appears to be over-gassing badly. Your plugs are the result of that-- consider a rebuild and maybe save someof the rebuild money on gas mileage.

[bud45]

Originally Posted by piecesparts

You could use a vacuum gauge to get the idle mixture screws set to their optimum setting, or you could do it by idle sound---your choice. The vacuum gauge will set the idle screws where they are at the point that they do what is the absolute best they can do.

This is done by connecting a vacuum gauge to the intake manifold source (such as a fitting just behind the carb. Then set your idle speed to a good setting like 700 RPM), and now note the vacuum reading. Next, turn the first idle screw inward until the idle drops off a little--and then turn the screw outward until the idle speed stops increasing and further adjustments out will not make it get any better (look for that point carefully). Now turn the other adjusting screw inward until the idle drops off and then adjust outward until the idle is no longer affected, just like the first screw. Now readjust the idle speed to 700 RPMs again. You will want to do the idle screw adjustment of the idle screws one more time to make sure that you have the mix adjustment at the OPTIMUM setting. ONCE you have found the sweet spot on the screws, TURN THEM INWARD an 1/8th of a turn and you are set.

Keep in mind if you are getting large amounts of fuel on your plugs, that the idle mixture screw are only affecting this when you are in the idle/air circuit, not the power mode of the carb. There very well could be a carb rebuild in your future, as it appears to be over-gassing badly. Your plugs are the result of that-- consider a rebuild and maybe save someof the rebuild money on gas mileage.

Yes, that was what I was concerned with...and I've had the carb apart before & found the float fitting/assembly was loose, dumping fuel. I replaced it with one in a kit I bought, but it's getting rough again. I may just go to a rebuild or buy a rebuilt carb & be done with it.

With my old Dodge, as mentioned before, I had 4 heat ranges over...I had a new carb and had messed around with different carbs (that was when I was single and had money!!!), but I went back to the stock two-bbl. & the hotter plugs & she ran clean. Wondered if I could do the same with the p/u.

New carb or rebuild definitely looks like the way to go- thanks!

[bud45]

Piecesparts, Greasemonkey72, I rechecked what I did...where's my "stupid" sign? I screwed the carb screws out, thinking it would lean it out- WRONG! I screwed them back in where they were, then slowly retuned it by ear and everything cleared up! I still have a slight stumble at highway speed, but I'll get more "into" it on my vacation next week...this solved the immediate problem, however, and it runs like a new/old truck! All I have is a dwell meter, timing light & a compression tester, so I'll have to obtain a vacuum meter for the test prescribed. I also have to find & re-read the manual on this engine....

Now, I get to cross the "stupid" off my sign & scrawl, "Teachable" across it!

THANK YOU!

[piecesparts]

Originally Posted by bud45

Piecesparts, Greasemonkey72, I rechecked what I did...where's my "stupid" sign? I screwed the carb screws out, thinking it would lean it out- WRONG! I screwed them back in where they were, then slowly retuned it by ear and everything cleared up! I still have a slight stumble at highway speed, but I'll get more "into" it on my vacation next week...this solved the immediate problem, however, and it runs like a new/old truck! All I have is a dwell meter, timing light & a compression tester, so I'll have to obtain a vacuum meter for the test prescribed. I also have to find & re-read the manual on this engine....

Now, I get to cross the "stupid" off my sign & scrawl, "Teachable" across it!

THANK YOU!

We charge DOUBLE for whippings and beatings, if you don't get it right the first time.

The idle can be set by ear, but I have found the vacuum gauge gives a fine touch to the process. Just don't overdo the turns out, to get that smooth idle.