Timing Gun Tricks?

Tornado · Jun 25, 2024

Have a need to brush off my few yrs old digital timing gun. Cannot recall having this issue last time i used it, but today could not get any function out of it....not the strobe nor the led display panel on back. Checked power at the aligators, all ok. Only switch is the trigger but had no effect. Could it just be a goner?

marshg246 · Jun 25, 2024

Tornado said:
Have a need to brush off my few yrs old digital timing gun. Cannot recall having this issue last time i used it, but today could not get any function out of it....not the strobe nor the led display panel on back. Checked power at the aligators, all ok. Only switch is the trigger but had no effect. Could it just be a goner?

Try opening it and putting a jumper around the switch - if the display comes on you know it's the switch. If not, look to see if it has a fuse and if so, is it blown.

If you find that it actually is dead, consider this: https://a.co/d/05SpIWXd

I bought mine in 2015 and it's still working fine - I don't even remember changing the batteries and it makes no difference which way the pickup is clamped on. When I press the button, a red indicator comes on tell me it's on.

BTW, some old digital strobes that get their power from the bike's battery can falsely trigger due to noise. That's why I replaced the old on I used on cars.

Tornado · Jun 25, 2024

Thanks, will likely open it up. It does have fuse on the power lead, which tests fine. Thought it might just need a signal on inductive pickup clamp before the display would come on but that seems odd as you need to select 2 or 4 cycle, advance degrees and put rpm or degrees on the display, all things to do prior to pulling trigger.

I do have an old school one that has a 2 or 3 inch spring that goes in line between plug and cap, no advance settings of course. But im trying to check my velocette and there is very little clearance between plug and engine/tank...having the raw spring sticking on there is bound to short out.

Tornado · Jun 25, 2024

What i have:

Amazon.com

grandpaul · Jun 25, 2024

Always use power from a battery that is not connected to the bike.

Read that many years ago and always have plenty around, so I always do.

Tornado · Jun 25, 2024

grandpaul said:
Always use power from a battery that is not connected to the bike.

Read that many years ago and always have plenty around, so I always do.

Yes, but in this case the bike had dynamo belt off, so no charging and no other electrical consumers on (its a mag ign). The LED display should come on when power leads connected to the battery, even with engine not running. Tried it on the Norton battery as well, no joy. Looks like it must be taken apart to investigate further.

johnm · Jun 25, 2024

Something I learnt only recently is that with a twin plug head depending on the circuit you may need to reverse the pickup on the plug lead. They have an arrow which normally points to the plug but sometimes you will need to reverse it.

Tornado · Jun 25, 2024

OK figured out the issue. For the first time ever, i was using my battery tender lead which is direct connect to batt terminals, with the SAE connector plugged into another battery tender SAE lead with alligator clamps at other end. On a whim i tried reversing polarity of alligators to the timing gun alligators, red to black and black to red, and there it was, ppwered on LED display.

So issue was my fault, thinking two SAE connectors plugged together just passed through batt polarity when in fact they make for reversed polarity at the clamps.

Mike40M · Jun 26, 2024

Great that you have one with reverse polarity protection.
I've also had need for pickup reversing on a magneto bike.

Tornado · Jun 26, 2024

Mike40M said:
Great that you have one with reverse polarity protection.
I've also had need for pickup reversing on a magneto bike.

Too bad it wasn't also reverse polarity warning

marshg246 · Jun 26, 2024

Tornado said:
Too bad it wasn't also reverse polarity warning

Also, too bad that companies don't add the little bit of circuitry required to remove the polarity requirement! That would also take away the potential of false triggering when using the vehicles battery and force them to do the kind of pickup mine has where the clamp can go either way.

It's amazing to me that they provide the "sexy" stuff like a display and options when all you need is the light to flash when the spark happens, but they don't do the things actually useful to the user!

I guess it's like car sales. Today, car advertising only tells you things like how many cameras and iPhone connectivity!

Tornado · Jun 28, 2024

Finally had another go timing my Velocette. Got power to gun. Got a reading of rpm at idle and when reving up. Switched hun to degree display and hit tirgger...strobe only came on sporadically. Confirmed pickup was fully closed and had arrow pointing toward sparkplug. Tried it other way around and no strobe at all. Could not proceed with timing check.

Got my vintage timing gun out with the in line spring to connected between plug and cap, but it leave exposed spring metal fairly close to cyl head and or tank metal
Could not start bike with that in place, so likely shorting to earth.
Had to leave it for now in frustration.

Timing Gun Tricks?

Similar threads