Timing Light RPM range?

levittownnick

Senior Chief Petty Officer
Joined
Jul 2, 2003
Messages
789
What is the typical maximum rpm a xenon type timing light will work to. Note 2-cycle engines fire twice the 4-cycle rate.

Thank you.
Nick
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
At higher RPMs the light stops flickering and is pretty much solidly on. No difference in 2 or 4 strokes.

Are you looking at a loss of spark at high RPM?
 

mla2ofus

Chief Petty Officer
Joined
Dec 30, 2008
Messages
571
levittownnick;n10481928 Note 2-cycle engines fire twice the 4-cycle rate. Thank you. Nick[/QUOTE said:
Depends on the engine. Most small 4 cycle engines with a magneto ignition fire every crankshaft revolution. Once at the top of the compression stroke and once at the top of the exhaust stroke. To your question, at high RPM it may appear to not be flashing but it still is.
Mike
 

dwco5051

Commander
Joined
Sep 14, 2008
Messages
2,326
Most hand held xenon stroboscopes for measuring rpm's have an upper limit of 12,500 rpm. I am guessing that the internal circuitry is different than a timing light but if the timing light can be used at even one half of that it should work on outboards at speeds at normal operating ranges but maybe not on chainsaws. Google portable stroboscopes for more info. Never used one with LED's but from the information on them you probably could check a bullet to see how fast it is spinning.
 

bigdee

Commander
Joined
Jul 27, 2006
Messages
2,665
The normal eye cannot detect a strobe above 3000 flashes per minute. A florescent light strobes at 7200/minute. But all of this is irrelevant when using the strobe to synchronize with timing pulley.
 

levittownnick

Senior Chief Petty Officer
Joined
Jul 2, 2003
Messages
789
Thank you gentlemen,
The reason I am asking is that I would like to check the timing of my 2-cycle 150 hp outboard at wide open throttle and do not know if my old timing light will work at that range. In any case it will be a challenge because in the light of day and bouncing on the water I may not be able to see anything. In the evening is a little more practical if the light will work at that rpm.
Thanks to all,
Nick
 
Top