procharger Posted March 11, 2023 Report Share Posted March 11, 2023 CTLS runs good but right side starts running rough after few min. Put a inductive timing light to check fire and it does not light up top side cyl. or the bottom same thing. Pull new plugs out they are sooted black. install two used plugs its running perfect again timing light is firing like it is supposed to. Then the other cyl. same side does same thing no fire top plug or bottom. Install two more used plugs starts running perfect again timing light is working correctly on both. called Dean and he said he has had this before on the right side of engine many times. Has anyone heard of this, mag check is perfect when its running right this has happened a couple of times, carbs have been gone through. I need to lean out the idle screw some I think that might help so its not to rich on idle. Will try that next. I find it hard to believe the plugs get sooted up and they stop firing, they are not wet just soot. Ideas Quote Link to comment Share on other sites More sharing options...
Tom Baker Posted March 11, 2023 Report Share Posted March 11, 2023 In 15 years I've had one carb that the float needle wouldn't seat right causing the engine to run rough, (rich), after idling for just a little bit. I sent it to LEAF, and they did some kind of magic withthe seat, and it fixed it. Quote Link to comment Share on other sites More sharing options...
procharger Posted March 11, 2023 Author Report Share Posted March 11, 2023 Today I adjusted the idle air screw out to about 2 turns maybe 2 1/4 and it looks to be good now, plugs are now tan like they are supposed to be not sooty ran for about 45 min. with no issues. Started several times. It is running like it should. Quote Link to comment Share on other sites More sharing options...
Anticept Posted March 11, 2023 Report Share Posted March 11, 2023 The carbs by nature run super rich at idle to ease cold running. Depending on how low you set idle, there is a chance it could become rich enough to stall out on its own. Thankfully, the old trick of adjusting the idle mixture screw is in the latest line maintenance manuals so there's your official data for it. Quote Link to comment Share on other sites More sharing options...
procharger Posted March 13, 2023 Author Report Share Posted March 13, 2023 It seems to have worked Quote Link to comment Share on other sites More sharing options...
procharger Posted March 13, 2023 Author Report Share Posted March 13, 2023 My question is just because they are sooted up why would plug stop firing. Quote Link to comment Share on other sites More sharing options...
Anticept Posted March 13, 2023 Report Share Posted March 13, 2023 It's probably coated in gas film that vaporized before you removed it. Tom made a point to me years ago that I can't assume that the fuel gas mix is perfectly hemogenous. And it's true. It could be that at idle, the bottom plug gets bathed in rich fuel that can still combust, while the stuff at the top is too dry when the spark fires and doesn't contribute. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.