Points Question

[Serendipity]

My corsette race bike was running fine for the race, but now its boggy and has little backfires (like bacon fat exploding) unless I revvv it really high. I'd been advised that the timing is off (now). How does this happen? The rattling from the engine loosened the stator plate? If so, Im guessing it was the one or two blocks I rode down H street.

[Mikeh]

If you have points on your stator plate then they may have vibrated loose and your point gap may be off which will affect the timing of the motor. the way to check points gap is by using either a feeler gauge or I beleive Darren once told me that he uses the cardboard paper of a book of matches to set the gap. But once the gap is set you should either static time the motor or use a timing light. I prefer using a timing light as mine has an advance/retard dial so all you have to do is make marks at TDC and the gun does the rest.

[Serendipity]

If you have points on your stator plate then they may have vibrated loose and your point gap may be off which will affect the timing of the motor. the way to check points gap is by using either a feeler gauge or I beleive Darren once told me that he uses the cardboard paper of a book of matches to set the gap. But once the gap is set you should either static time the motor or use a timing light. I prefer using a timing light as mine has an advance/retard dial so all you have to do is make marks at TDC and the gun does the rest.

presumably (hopefully) the marks are still on there from when it was correctly timed. It just seems odd to me that I can ride a scooter A for over a year and it still runs like a top (including a long ride to gettysburg and back), but putting only 1/5 the mileage on scooter B, it throws the timing off.

[AirborneVespa]

I split this topic into its own thread because, well, it didn't have anything to do with the plug chopping sticky.

[tony]

presumably (hopefully) the marks are still on there from when it was correctly timed. It just seems odd to me that I can ride a scooter A for over a year and it still runs like a top (including a long ride to gettysburg and back), but putting only 1/5 the mileage on scooter B, it throws the timing off.

This could be from the ramps that open and close the points - if they are pitted, or catch on the points in any way, they can slowly grab them and knock them out of time.

[Serendipity]

presumably (hopefully) the marks are still on there from when it was correctly timed. It just seems odd to me that I can ride a scooter A for over a year and it still runs like a top (including a long ride to gettysburg and back), but putting only 1/5 the mileage on scooter B, it throws the timing off.

This could be from the ramps that open and close the points - if they are pitted, or catch on the points in any way, they can slowly grab them and knock them out of time.

I thought it was the eccentric ring on the inside of the flyywheel that taps the one point against the other? So he timing was fixed and now it is unfixed again after a similar number of miles. Could it be that for some reason the bolt keeps coming loose?

[AirborneVespa]

I thought it was the eccentric ring on the inside of the flyywheel that taps the one point against the other? So he timing was fixed and now it is unfixed again after a similar number of miles. Could it be that for some reason the bolt keeps coming loose?

What kind of screws are holding your points in? Are they flat head or phillips? Those get mangled and become hard to really screw into place. Another thing is the hole could be wobbled a bit which means the screws aren't holding.

Did you do the work yourself? or did someone else do it? Did you just re-do the timing or did you replace the points?

A lot of people with points bikes replace the phillips or slotted screws with screws of the same size that have bolt heads, so you can use a socket to put them on.

You can also put blue locktite on the screws when you put them in - that typically helps them hold longer. never use the red locktite though.

[Serendipity]

What kind of screws are holding your points in? Are they flat head or phillips? Those get mangled and become hard to really screw into place. Another thing is the hole could be wobbled a bit which means the screws aren't holding.

phillips.

Did you do the work yourself? or did someone else do it?

Iain (deadsled) "helped" me, which really means he did it and I handed him tools and tried to commit it to memory. He's run off to California so this time it will be my "capable" hands.

Did you just re-do the timing or did you replace the points?

just redid the timing

A lot of people with points bikes replace the phillips or slotted screws with screws of the same size that have bolt heads, so you can use a socket to put them on.

that sounds like a good plan....I'll remove the screws .. I know that there was some play in the plate - slots instead of holes so that it could be adjusted a little.

You can also put blue locktite on the screws when you put them in - that typically helps them hold longer. never use the red locktite though.

cool! thanks!

[AirborneVespa]

[that sounds like a good plan....I'll remove the screws .. I know that there was some play in the plate - slots instead of holes so that it could be adjusted a little.

You can also put blue locktite on the screws when you put them in - that typically helps them hold longer. never use the red locktite though.

cool! thanks!

Are the points brand new? If they aren't new (or new-ish) I'd order new points before undertaking work on it. They're pretty damned cheap and it's safe insurance - esp since it's such a pain in the ass to work on them.

But yeah, same size screws with bolt heads are easier to work with (I've found). And that blue loctite will keep them in place longer.

[Serendipity]

Are the points brand new? If they aren't new (or new-ish) I'd order new points before undertaking work on it. They're pretty damned cheap and it's safe insurance - esp since it's such a pain in the ass to work on them.

Nope. I'll order new ones.

[Serendipity]

Things went downhill quickly - I ended up having to push my scooter home from just below U street to mt pleasant...in 100f heat. It wouldn't even go...Thank god it was the smallie, otherwise I'd surely have had a heart attack. Sofa king HOT

[dirtyhandslopez]

Did you find out what it was yet? I'm guessing bad soldering on wire to the condensor.
Timing needs to be set correctly before messing around with your points. Set your timing, then set your points to 15 thou, then make sure the points open at the timing mark you have made. Simples.