Redneckedness Posted April 2, 2020 Author Share Posted April 2, 2020 Are you sure the marks on the harmonic damper actually correlate to TDC #1? 460's can get inductive misfire between #'s 7&8. It's recommended not to run these wires right next to one another. When you say "backfire" is it an explosion in the exhaust, or is the engine spitting up through the carb? If the latter, you'd better go check all the vacuum lines and caps. It's very easy to pop one of those, especially on the back of the carb spacer where you won't see it's broken. It was in the exhaust. What I'm thinking is that it was so retarded that maybe it was firing as the exhaust valve was opening. That would explain the sudden slow down at the same time the engine backfired. Problem is I'm new to this so i don't have much experience. I realized I was making a rookie mistake because I wasn't disconnecting the vacuum advance when i was trying to set the timing. Link to comment Share on other sites More sharing options...
Gary Lewis Posted April 2, 2020 Share Posted April 2, 2020 It was in the exhaust. What I'm thinking is that it was so retarded that maybe it was firing as the exhaust valve was opening. That would explain the sudden slow down at the same time the engine backfired. Problem is I'm new to this so i don't have much experience. I realized I was making a rookie mistake because I wasn't disconnecting the vacuum advance when i was trying to set the timing. Depends on the source of vacuum to the advance. Some are "timed", which means that there's none when the throttle is closed, and some are "manifold", which means it is there all the time. If manifold then your timing will be way off if you set it with the vacuum attached. Link to comment Share on other sites More sharing options...
Redneckedness Posted April 2, 2020 Author Share Posted April 2, 2020 Depends on the source of vacuum to the advance. Some are "timed", which means that there's none when the throttle is closed, and some are "manifold", which means it is there all the time. If manifold then your timing will be way off if you set it with the vacuum attached. I think its vacuum. Ill try it tomorrow with the vacuum disconnected and see what happens. As well as it ran, the only thing that makes sense is the carb at idle wasnt giving it enough fuel on one side. Makes sense since its a dual plane intake. As soon as i goosed the throttle it would come back to life, running strong. Link to comment Share on other sites More sharing options...
Gary Lewis Posted April 2, 2020 Share Posted April 2, 2020 I think its vacuum. Ill try it tomorrow with the vacuum disconnected and see what happens. As well as it ran, the only thing that makes sense is the carb at idle wasnt giving it enough fuel on one side. Makes sense since its a dual plane intake. As soon as i goosed the throttle it would come back to life, running strong. Both idle circuits have to work for it to run properly at idle. Have you tried blowing it out with compressed air? Link to comment Share on other sites More sharing options...
Redneckedness Posted April 2, 2020 Author Share Posted April 2, 2020 Both idle circuits have to work for it to run properly at idle. Have you tried blowing it out with compressed air? Will do that tomorrow. Can i use carb cleaner when i do it? Link to comment Share on other sites More sharing options...
Gary Lewis Posted April 2, 2020 Share Posted April 2, 2020 Will do that tomorrow. Can i use carb cleaner when i do it? You can try carb cleaner, but compressed air is much better. Link to comment Share on other sites More sharing options...
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