Has anyone had a flathead jump time. It was running great and now it acts like it's not in time. Does anyone know what could have happened to this damn thing? Why would it all of the sudden jump out of time? Any help would be greatly appreciated.
That happened to me before but it turned out more serious than timing, the split valve guide ran up on the valve and jammed the valve which in turn broke the cam when I kept screwing with it trying to start it. Assuming you checked the distributor to see that it hadn't loosened up, I would first pull the intake (easiest and fastest) and look to see that all is well. Then if that isn't the problem I would pull the timing cover to see what is going on there. good luck 31acoupe
What 31Acoupe said!! Pull your plugs and see what they tell ya, as well. Any loud expensive noises coming from the engine? Flatman
You might want to check out the dizzy drive gear. The pin may have sheared. Then do a compression test to see what the valve train is doing.
Check to make sure the dist gear on the cam did not come loose. Also check dist gear on end of dist shaft. Plus do what everyone else said.
Explain the symptom a bit more completely? What version of flathead? What does a timing light tell you? Some simple problems mistakenly taken to be timing: Plug wire Plug, Champions suck. Use NGK BL6 Bad condenser and fried points Bad coil causing low voltage and misfiring Vacuum leak Hung valve Those are just a sample.
Since flatheads don't have a chain, they can't really "jump time". About all they can do is lose some teeth and stop all together. Does the rotor still turn when you turn the engine over?
Thanks everyone for your input. This is what I have tried so far. I pulled the timming cover (all is good). The button turns fine when I turn the motor over. When I pull a spark plug wire off and turn the motor over I get a realy good arc. I pulled a plug and gas is getting to them.The plugs look good to me New carb, new spark plug wires, new cap and button.This is an 8ba My question is if the points and condenser are fried would it still fire. This mabey a dumb question but it seems to me if the points and condenser are bad it would'nt fire at all. I hope I'm wrong. Mabey someone can explain to me what the point actually do. Thanks for all the help.
combining what some of the above have said, this is the way I would go about it. from least invasive to most. firstly does the motor still run? if yes then... start the motor and then go around and remove one spark plug wire to see if the motor DOESNT change, if this happens, then it narrows it down to that chamber.from there it could be the wire, plug or valves. put the timing light on and see what that tells you. change the points and condensor, does this improve it? do a comp test, this will tell you if something nasty has happened. if you find one cylinder is down, look into the cylinder to see if one of the valves seems to be stuck, if so try to tap it back down and put some oil in the cylinder to help lube it a little. if the cylinder is down and you can see that the valves are opening and closing, then put some oil in there and redo your comp test, this will tell you if its rings. from here, I would pull the intake and then check that the valves are doing what they are meant to do from inside, is it a broken guide or spring or valve? or knocked a lobe of the cam. from here its more serious, look at the timing gear, then if it was me , it would be pull the motor, onto the engine stand and pull the heads or sump or both and see what the hell it is! at this point things can be bad... hope this gives you some guidance...
It looks like nobody stepped up to the plate with the answer to your question, so I'll take a shot at it. More knowledgeable people will no doubt jump on the bandwagon to correct what I have wrong. The truth is, I don't know beans about automotive electrical systems. The points are a switch. When closed, a low voltage current is applied to the coil allowing it to build a high voltage charge. When they open, the low voltage charge is collapsed causing the the high voltage windings of the coil to discharge high energy to the distributor cap and on to the correct spark plug if things are lined up correctly. Since timing is determined by when the contacts open, as the contacts wear or burn up, timing changes. Badly pitted and burned points can even have an erratic spark. As the rubbing block wears against the distributor cam, timing also changes. Condensers help smooth out the spikes that come with the coil's field collapse to keep the points from burning/pitting prematurely. If you find the points wearing too rapidly, you my need to check to see if the ballast resister is not in the system or not wired properly. You didn't ask about condensers, but there is an excellent discussion on the flathead Techno Source at this link: http://www.btc-bci.com/~billben/condens.htm
Yes it will run with fried points not well but it can still run. Like Merc said describe what the engine is doing or not doing. What won't it do that it did before and when won't it do it? I had the contacts on a point set weld together. The arm opened and closed by making contact with the back of the contact. I drove it to the parts store for a replacement. (not a flathead) Did you see if the dizzy was loose at the hold down?
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