Notices
1961 - 1966 F-100 & Larger F-Series Trucks Discuss the Slick Sixties Ford Truck

Need tuning advice

 
  #1  
Old 07-03-2019, 12:00 AM
jjriley97
jjriley97 is offline
Senior User
Thread Starter
Join Date: Mar 2019
Posts: 108
jjriley97 is starting off with a positive reputation.
Need tuning advice

I need some advice on tuning my motor. The motor is a 300 with a Carter 1bbl. It smells like it is running rich and there is a ton of carbon build up on all 6 plugs. It runs rough at idle, but does ok going down the road. The distributor cap and plug wires are new. The rotor and plugs are not and I'm not sure of the age. Where would you guys start?
 
  #2  
Old 07-03-2019, 05:17 AM
Crop Duster's Avatar
Crop Duster
Crop Duster is offline
Posting Guru
Join Date: May 2015
Location: Tri Cities, TN
Posts: 1,280
Crop Duster is gaining momentum as a positive member of FTE.
Originally Posted by jjriley97 View Post
I need some advice on tuning my motor. The motor is a 300 with a Carter 1bbl. It smells like it is running rich and there is a ton of carbon build up on all 6 plugs. It runs rough at idle, but does ok going down the road. The distributor cap and plug wires are new. The rotor and plugs are not and I'm not sure of the age. Where would you guys start?
The golden rule is ignition first then carburation. A rotor and a new set of plugs are pretty cheap. Also this has been discussed a lot, "crappy made in china condensers", if you have one in there get it out.
Hopefully you have a dial back timing light.
Check the initial timing, book says 6 degrees manual, 10 degrees auto, I would use 10 degrees regardless of trans, unleaded needs a little more initial timing than leaded gas.
After you set the initial reconnect the vacuum advance. You should see around a 20 degrees additional advance if the vacuum advance is working correctly. If it's working the engine should speed up an smooth out.
To check the mechanical advance disconnect the vacuum line an plug it again, bring the engine up to around 2000 rpm then depending on the distributor you have you should see around 25 degrees additional advance.
If all that checks out then start looking at the carburetor. It took me longer to type all that than it takes to do it.
 
  #3  
Old 07-03-2019, 08:02 AM
jjriley97
jjriley97 is offline
Senior User
Thread Starter
Join Date: Mar 2019
Posts: 108
jjriley97 is starting off with a positive reputation.
Thank you for the info. Hopefully this will knock it out.
 
  #4  
Old 07-03-2019, 09:17 AM
Tedster9's Avatar
Tedster9
Tedster9 is offline
Post Fiend
Join Date: Apr 2002
Location: Waterloo, Iowa
Posts: 15,671
Tedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputation
Post a close pic or two of a plug. Keep in mind fouled plugs don't really recover, especially gas soaked plugs. They tend to misfire. Don't overlook ground cables and the charging system itself, need a good HOT spark, and then clean up the carb. Make sure the float level is set correcfly and take care to get idle mixture screws dialed in. Once plugs foul out real bad, then it's time for another set of plugs. Modern gasoline burns much cleaner than leaded gasoline ever did, there is little "color" when everything is dialed in right. When I first got my slick the plugs looked like they were painted with black Krylon. LOL
 
  #5  
Old 07-03-2019, 10:16 AM
Old Coyote
Old Coyote is offline
Senior User
Join Date: May 2012
Posts: 305
Old Coyote is starting off with a positive reputation.
Agree on the ignition suggestions. Another thing to be watchful for is vacuum leaks. A leak can cause all kinds of grief, like rough idle, and sometimes guys will try to compensate for it by stepping up idle, stepping up fuel ratio, etc.
 
  #6  
Old 07-03-2019, 10:42 AM
jjriley97
jjriley97 is offline
Senior User
Thread Starter
Join Date: Mar 2019
Posts: 108
jjriley97 is starting off with a positive reputation.
Thanks guys.

As far as the carbon on the plugs, think spray painted with flat black, a lot of it. My gut is saying they are fouled. I'm going to go ahead and replace the plugs, rotor and condenser this weekend to have the ignition system pretty much taken care of. I will probably change out the battery cables also. They are not in the best of shape either. I will then check the timing and hopefully things will be looking up.

I already went through and took care of vacuum leaks once and I think, think being the operative word here, that they are taken care of.

What's the best way to clean out the carbon buildup from the cylinders after doing all of this and things are running right? Will it burn off on it's own? Been a while since I've had a classic of any kind.
 
  #7  
Old 07-03-2019, 11:58 AM
Tedster9's Avatar
Tedster9
Tedster9 is offline
Post Fiend
Join Date: Apr 2002
Location: Waterloo, Iowa
Posts: 15,671
Tedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputationTedster9 has a superb reputation
Originally Posted by jjriley97 View Post
As far as the carbon on the plugs, think spray painted with flat black, a lot of it. My gut is saying they are fouled. I'm going to go ahead and replace the plugs, rotor and condenser this weekend to have the ignition system pretty much taken care of.
Be careful, the replacement condensers available today at the chain stores are absolutely no good. If you can find an old one laying in a junkbox that one might be OK. The problem even there is they are getting on in age, and absorb moisture and short out, or lose their insulation resistance. Points and condenser are kind of tricky to setup right even when the components are good, if one is not experienced. If you can find one made by Motorcraft locally that's been sitting on a shelf or something. Pull a plug wire and ground a spare plug on the block somewhere. A "remote starter switch" is really handy here. It's important to look at the quality of the spark. In points ignition the spark should be blue and make a snapping sound in the air. If it's a weak or thin spark and yellow or pink in color in the open air it won't run well under compression.

I will probably change out the battery cables also. They are not in the best of shape either. I will then check the timing and hopefully things will be looking up.
If the main battery ground cables, ground cables to engine and frame, firewall are original (or even just kinda old) they really have to be replaced. The starter won't work well, the battery won't get charged as well as it might. the engine won't start as easily or even run as hot as it should, the headlights will be weak, etc.

What's the best way to clean out the carbon buildup from the cylinders after doing all of this and things are running right? Will it burn off on it's own? Been a while since I've had a classic of any kind.
It will, though this is why you want to attack the problem from both the ignition and carb angles. Weak spark can't ignite normal air/fuel mixtures, especially under load and acceleration, going up hills etc. One rookie mistake people make with fouled plugs is using a "hotter" plug when the fouling problem is really the carburetor or ignition, or both. Use the stock plug, stock heat range plug, they will work perfectly. I like Autolite and NGK brand spark plugs.

Let's back up a second though. For general engine diagnostics the tune-up manuals always recommend a starting first with a cylinder compression test. This lets you know the overall internal mechanical condition of the engine. The reason for this, if there is a major fault you might not want to spend any time or money on the engine, and a tune-up won't do much good anyway.

A mechanic's vacuum gauge costs about $15 to $20, and pound for pound dollar for dollar the most useful tune-up and diagnostic tool in anybody's tool box. Think of it as an old school steampunk scan tool. They will also display the overall engine health, cylinder compression, vacuum leaks, exhaust restrictions, valve problems, ignition timing and carburetor idle mixture settings, also selecting a carburetor power valve, jetting. Nod your head "yes", you want one. If you want to drive a classic reliably it will need tuning up.

A mechanic's vacuum gauge will also measure fuel pump pressure output, and this is where carburetor tuning effectively really begins. Too much or too little pump output, either causes trouble. Mike's Carburetors has a page at his website where all the carburetor manuals are available to download, carbs are pretty simple but there's all sorts of settings and adjustments that have to be made or they will waste LOTS of gas.

This all sounds overkill but a careful, deliberate methodical approach saves countless hours and you'll end up with a much better result that lasts.
 
  #8  
Old 07-03-2019, 03:23 PM
jjriley97
jjriley97 is offline
Senior User
Thread Starter
Join Date: Mar 2019
Posts: 108
jjriley97 is starting off with a positive reputation.
Thanks for the advice. Along with the truck, I inherited the tools in the shop along with some parts. I'll have to see if there is a condenser in the parts at the shop when I go back up there. There is a compression tester in the tools so I'll be good there. This'll be a learning process for me that I'm looking forward to.
 
  #9  
Old 07-06-2019, 10:23 AM
pbmoss
pbmoss is offline
New User
Join Date: Nov 2017
Posts: 6
pbmoss is starting off with a positive reputation.
A vacuum gauge will answer many engine questions and help you tune the carbs.
 
  #10  
Old 07-08-2019, 12:21 AM
wcs69rat
wcs69rat is offline
Junior User
Join Date: Jul 2014
Posts: 63
wcs69rat is starting off with a positive reputation.
Put a Pertronix ignition module in the distributor and ditch the points and condenser.
 
  #11  
Old 07-08-2019, 09:44 AM
jjriley97
jjriley97 is offline
Senior User
Thread Starter
Join Date: Mar 2019
Posts: 108
jjriley97 is starting off with a positive reputation.
Well don't I feel sheepish. I seemed to remember seeing them in there, but the points and condenser weren't there when I went to change them Dad had already converted it.


I am thankful it's one less thing to mess with. The rotor and new plugs should be here tomorrow. My local parts store didn't have the plugs in stock. Once I get them changed, I'll start going through everything suggested here and update on what I find. Thanks for the assistance guys.
 
  #12  
Old 07-09-2019, 11:25 AM
jjriley97
jjriley97 is offline
Senior User
Thread Starter
Join Date: Mar 2019
Posts: 108
jjriley97 is starting off with a positive reputation.
Well, here is where I am. I started looking at the battery cables to ensure I'm getting good power. They were in horrible shape and I have replaced both the positive and negative cables. The positive cable was black almost all of the way through and the connections can be seen in the picture. There was a nut on there, I was working on it when I took the pic.




Now that power is good, time to move on to ignition. I got the plugs in, but the rotor has not yet arrived. I have replaced the plugs (NGK), wires, and distributor cap. No change. I don't think the rotor will make a difference, but will change it just to rule it out. Once I have it changed is there anything else in the ignition system that could be causing it to run rough or do I move on to the carb with the vacuum gauge? It was running great when I brought it home and then this started. Sorry for all of the questions, it has been a very long time since doing any of this.
 
  #13  
Old 07-09-2019, 11:55 AM
TA455HO's Avatar
TA455HO
TA455HO is offline
Post Fiend
Join Date: Aug 2012
Location: Seattle, WA
Posts: 5,364
TA455HO has a very good reputation on FTE.TA455HO has a very good reputation on FTE.TA455HO has a very good reputation on FTE.TA455HO has a very good reputation on FTE.
Have you looked at your ignition timing yet? If timing is set too far retarded then fuel is not completely burned by the combustion process resulting in a strong fuel odor and plugs can get fouled.

My 1966 shop manual has 23 pages of "General Ignition System Service" and it goes into lots of Coil Tests (primary circuit, secondary circuit, coil to ground test, etc., etc.), Resistance Wire tests, Distributor checks, High Tension wire tests, etc. - a lot of things to consider that are ignition related.
 
  #14  
Old 07-09-2019, 12:40 PM
Crop Duster's Avatar
Crop Duster
Crop Duster is offline
Posting Guru
Join Date: May 2015
Location: Tri Cities, TN
Posts: 1,280
Crop Duster is gaining momentum as a positive member of FTE.
That distributor you have pictured is either a Ford Duraspark or an MSD. Any parts house in the country should have a rotor for one of those. If you follow the wiring from the distributor you will find an Ignition Control Module somewhere. It should say Ford or MSD. One word of caution on a Duraspark they have very high secondary voltage if you are going to spark check it never remove #3 or #5 wire on a 6cyl. engine while it is running or it could arc to the stator and damage it. If you are going to check the spark quality pull the coil wire from the distributor and put a new spark plug on it, make sure it is well grounded then spin the engine with the starter and observe.
 
  #15  
Old 07-09-2019, 01:38 PM
jjriley97
jjriley97 is offline
Senior User
Thread Starter
Join Date: Mar 2019
Posts: 108
jjriley97 is starting off with a positive reputation.
I will be in the garage again on Thursday evening and the timing will be the next thing.

I looked through all of dad's manuals and surprisingly he did not have the set for this truck. I'm going to have to get them at some point. The distributor is a Ford one and the control module is mounted on the inner fender. They were just out of the rotor and had to order one in. Small town life gets you sometimes. Thanks for the tip on the #3 and #5. I was thinking any spark checking is always done on #1, correct or no?
 

Thread Tools
Search this Thread

Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.