Continued engine problems with my 129

[J-Mech]

Originally Posted by ironman

That's why it is important that the points close exactly on the "S" mark so that the spark occurs just slightly before the piston reaches TDC (which is the "T" mark).

Open, not close. When they open, ignition spark occurs.

[three4rd]

Originally Posted by ironman

Yes, the points stay open most of the flywheel rotation. They only close and open again very quickly to send a burst of current through the coil, which at that instant amplifies the current to give the burst of spark across the plug electrodes. That's why it is important that the points close exactly on the "S" mark so that the spark occurs just slightly before the piston reaches TDC (which is the "T" mark). The spark occurs before TDC because the high speed of the engine rotation puts the piston just past TDC by the time the spark ignites the fuel.

The .020 setting is really more of a ballpark setting. You may find that after you get your test light and finally get everything set just right on the "S" that the points may measure more or less than .020.

The points are closed well before the S appears if I'm seeing everything correctly. Here is what I just wrote down (I know this is very non-technical). Again, all this is based on looking at the points with the cover off, looking through the site hole, and observing piston motion through the spark plug hole.

Points start to open - no mark in window - no piston movement
Points open - still no mark - piston coming up
Points open - still no mark - piston at TDC
Points start to close - still no mark - piston on the way down
Points closed - S appears - piston on the way down
Points closed - T appears - piston on the way down
After this the engine turns for quite awhile with seemingly nothing happening (at least visibly)

[J-Mech]

See my above posts.... don't want you to overlook them with all the "action" in this thread.

[three4rd]

Originally Posted by cubs-n-bxrs

You obviously have the PTO clutch basket and the flywheel confused.

I know the difference. PTO is in the front. Flywheel has the S and T marks on it. I don't have the PTO engaged right now and so it's not even moving.

[three4rd]

Originally Posted by J-Mech

You could disconnect the springs. You could also adjust the exhaust valve to have a very wide gap. Wide enough it should stay closed. But, it's really not worth the effort. If your engine is losing oil... only two ways that is possible. It's either leaking it, or burning it. You never said it had any leaks.




No. Not unless the charging system is also not working. But you don't ever have to jump it correct?




Could be a bad battery with not enough voltage. More than likely a timing issue.




$5 says you're seeing the exhaust valve move. You can't see the piston through the plug hole on a K series. At least not easily. Heard this story time and again on here how the piston is moving.... "newbies" always see the exhaust valve and mistake it for the piston.

Has never leaked oil. Have not had to jump it for years - used to for awhile when I had a weak battery. Never thought about the exhaust valve! If I'm not seeing the piston then I guess I'm seeing the valve. That would explain alot. I think it's time for me to stop monopolizing the forum and simply have my brother look at this thing and get it working again. I could go around and around here for the next year and probably be no farther along UNLESS it turns out to be the timing. I'll ignore the exhaust valve.

Curious though...why would the exhaust valve be directly below the plug? When the plug fires...how does it ignite the fuel/air mixture?

[ironman]

Originally Posted by J-Mech

Open, not close. When they open, ignition spark occurs.

Sorry, I got my mords wixed.

[cubs-n-bxrs]

IF, however, I put the flywheel on at the wrong place (is that even possible to do?), then of course the S and T marks would not correspond to when the points open.

That's why I asked if the key stayed in place when you reinstalled the flywheel.

[J-Mech]

Originally Posted by three4rd

Has never leaked oil. Have not had to jump it for years - used to for awhile when I had a weak battery. Never thought about the exhaust valve! If I'm not seeing the piston then I guess I'm seeing the valve. That would explain alot. I think it's time for me to stop monopolizing the forum and simply have my brother look at this thing and get it working again. I could go around and around here for the next year and probably be no farther along UNLESS it turns out to be the timing. I'll ignore the exhaust valve.

Curious though...why would the exhaust valve be directly below the plug? When the plug fires...how does it ignite the fuel/air mixture?

As long as a spark plug is in the combustion chamber, location only matters to get the best possible combustion. Early K series the plug was between the intake and exhaust valves. It was moved to the front over the exhaust valve, we believe, to get a better, or more clean burn. It seems to be a better location, as the guys who pull or "ramp up" the power of the motor say that head can make a bit more power.

I agree.... probably time to just get it over to your bro.

[J-Mech]

Originally Posted by cubs-n-bxrs

IF, however, I put the flywheel on at the wrong place (is that even possible to do?), then of course the S and T marks would not correspond to when the points open.

That's why I asked if the key stayed in place when you reinstalled the flywheel.

He didn't take the flywheel off. He was talking about the basket pulley. He's never had the engine out of the tractor.

[three4rd]

Originally Posted by ironman

Sorry, I got my mords wixed.

LOL...good one