1978 EZGO points/timing question

[ddesi16127]

Hi all - I have a question about this gas cart I have and I am surely not a mechanic...just a DIY'er. After tearing it all down and putting it back together, the cart just doesn't run quite right. Seems to struggle on upward grades, kind of cuts in/out quickly at times, overall slower than I would expect from a new rebuild. So I started looking at the timing. I know this is a repeat problem asked in this forum, but I feel like something is odd.

If I am following the manual correctly, I have placed my multimeter in-line with the "black primary wire from negative side of the ignition coil". Set to buzz or read Ohms, the buzzer immediately goes BUZZ. In fact it continues to BUZZ until I reach TDC (going in the 'Forward' direction). I can see the markings on the flyweel as well as see the piston position in the cylinder from underneath the cart. Once I move past TDC the BUZZ stops for maybe 10 degrees more, then the BUZZing starts back up again for the rest of the cycle around until I get back to TDC.

Based on this, it would seem power to the coil is happening almost continually and I would assume then that the spark plug is almost constantly on. This seems like the opposite of what it should be doing. Am I misunderstanding how this works?

So now I bring in the points. I thought the points would stay open (with proper gapping) until the contact surface reaches a dip causing the points to close. So I remove the flywheel and again see the complete opposite of what I thought I would see. The points are closed for almost the entire cycle riding on the inner part of the flywheel (reason for constant BUZZ). Not sure what to call that part...but it's keyed and is completely round except for a small section that humps UP instead of DOWN. The hump UP pushes the points open briefly (reason for brief NO BUZZ after TDC is met). Based on this setup, there's nothing for me to gap (per manual: .013-.015 inch).

I have new points and a new condenser to install, but based on what I am seeing, I'm not sure these will make a difference.

Can anyone verify or help explain how this should be working?? Thanks in advance...

[Cartmaster]

Generally speaking, It is working normally, the coil fires the plug at the moment the points open. It is this gap in the points you need to check when the points arm is resting on top of the lobe ( hump ) The timing is set to the marks at the moment the points start to open. ( buzzer stops )

[cart around]

To add a little, your plug is firing at TDC. You want to advance the timing so it fires a few degrees before TDC.

[ddesi16127]

Okay - THANK YOU both for confirming how this works. Based on where the timing plate is currently set, I think there's room for improvement to set it BTDC.

Since I have the flywheel off, I am going to install the new parts anyway and make the adjustments you both have mentioned. The brushes appear to be fine still (can't seem to find the direct replacements anyway).

Thanks again for the information!

[ddesi16127]

Well.....new condenser & new points are in place. I've marked the flywheel so I can see where the top of the lobe is from the outside and I can't adjust the points gap to where it needs to be. In fact, set with the contact point as far as it will go on the top of the lobe barely opens the points. Definitely not enough to stick a thickness gauge in.

Any ideas? Have you seen this happen before? Thanks...

[Dabble Inn]

I can only think of three reasons, either wrong points or wrong points plate. Or even worse a worn lobe

[ddesi16127]

Having only owned the cart for 2 of its 45 years history, who really knows for sure??

According to Vintage, these are the replacement points/plate. So I'm guessing the lobe has really worn down. There wasn't even any room to move the points plate to set timing ahead of TDC.

So what I decided to do yesterday was grind the screw grooves on the plate further so it would sit in place, but lower to allow for BTDC. That seemed to work, but then the contact still wouldn't open up the points at TDC.

So today I grinded notches in the plate so it will sit closer to the flywheel (and closer to the lobe when it passes by). Initial mockup looks good. I will post back after I get it all buttoned up - hopefully with good news to report.

[Dabble Inn]

I was going to suggest doing that very thing next, at this point you have nothing to lose. And with some careful precision it can be done with success, I had to do it on a Harley buggy a few years ago......

That thing had been through way too many hands before mine, the points plate was not original and already modified but wrong along with the timing marks on the flywheel were way off. Had to get my degree wheel out and punch in new marks where they belong, very strange ordeal.

[ddesi16127]

I finally got the cart out for a test drive last weekend. It ran really good compared to how it did before. Engine sounded pretty smooth and didn't throw a lot of extra clunks going up or down grades.

Yeah this is all new to me so thought it pretty odd to have to modify those parts to work right. I think after the install I'm just at or close to 20 degree BTDC and maybe just a few degree past TDC for reverse. I learned a lot so I won't complain!

[Dabble Inn]

That sounds a little too far advanced.....

Meaning; you should try to retard it a little so as to get some advanced timing for reverse. But at least you're getting a handle on it now, glad to hear it's running....

I'll see if I can find some info on what the book says for how advanced it should be....

Generally speaking for any engine, the farther advanced the hotter it'll run. Don't want to make it run hotter then it should be, especially for an air cooled engine.