Running rough
 

Well I let my son drive my car that has two 97 Strombergs. He drove it without the chokes being fully open after it was warmed up. It is now running like crap sounds like it is missing and backfiring. I think that the plugs got fouled because of running to rich. What do you all think. Thanks

Re: Running rough
 

don't sound like plugs to me ,could have dragged some dirt into the jets do you have a filter ,short out each plug to tell if its that .

Re: Running rough
 

When I check misfires I use my indutive timing light on each wire just to see if it is flashing evenly. Check your oil and if the level is up change it. I clean plugs by pulling them and burning the soot off with a propane torch.

Re: Running rough
 

Lets start with something simple instead of all this guessing. Now, you said the boy run it quite awhile with the choke half out, so let pull the plugs and see if there all sooty. If so the engine will run ruff. The only way to clean the plugs is have them sand blasted with fine bead so you can blow them out good, course bead will stick up inside the plug. While you've got the plugs out it's a good time to check the compression. It's very simple and you'll never know if you have a bad valve until you take a comp test. If the comp is all good your stepping in tall cotton. So, do those simple little test first. So ain't that simple. Walt

Re: Running rough
 

Pulling the choke richens the mixture. If it has an internal leak in one of those carbs, it will run rich so that's probably not the problem. If it has a clogged jet or metering tube it will run lean. Pulling the choke will correct a lean mixture. Fuel delivery not keeping up, like a problem with a pump or flow can be a cause.

Re: Running rough
 

How much are a new set of plugs? Spend the money, solve your problem.