Timing Light

[Yikes]

After going too long without one, I’m going to buy timing light so I can finally get that high revs at idle problem fixed.  Can anyone offer advice on what to look for in a timing light and what to stay away from?   Certainly a xenon bulb with a bright bright flash is a must, but beyond that, I’m not sure what is desirable.  A metal body? Is the “advance” feature needed for timing the r65?  (I’m really not sure what that even is.)  Is there a really good timing light that anyone’s had a good experience with they would recommend?  I’d like something of good quality, but not more than is needed to keep the airhead running right.  :-/

Thanks for any help,

John M

[Justin B.]

Xenon is mandatory, metal body is good, I prefer an inductive pickup.  I have an old "SunTune" light but have no idea what is available now.  I would look at Pawn Shops as one might be able to pick up a nice Mac or Snap-On fairly reasonable.  I doubt if the advance feature would be much good in our case as the exact number of degrees needs to be known (available in manual I suppose).  If I remember correctly you dial in the number of degrees of advance in, rev to the required RPM and the advance feature "delays" the triggering so your original TDC mark aligns with the pointer.  This keeps you from having to search the flywheel/harmonic balancer for, and marking, the correct number of degrees you want to check for.  This would be more of a benefit for cars...

[Lucky_Lou]

for the amount of use you give them the best bet if you cannot borrow one may be to hire one i borrowed a snap on one which was very good but they cost an arm and a leg.
Lou

[MrRiden]

Cheap, works, guaranteed. No bells or whistles. Got one in my box and it gets the job done.
http://www.sears.com/shc/s/p_10153_12605_00921027000P?keyword=timing+light

Also don't know if it's true but Ive been told it's best to use a power source other than the battery / charging system of the vehicle you are timing. Something about pulse current. This may only apply to certain brands of bike that employ a full wave rectifier in the charging system. Or maybe it's an urban myth.
rich

[montmil]

...Also don't know if it's true but Ive been told it's best to use a power source other than the battery / charging system of the vehicle you are timing. Something about pulse current. This may only apply to certain brands of bike that employ a full wave rectifier in the charging system. Or maybe it's an urban myth. rich

No myth. The BMW manual states this plus you are to use the right-hand spark plug lead for the inductive pickup clamp.

Borrow a timing light for the limited amount of use you will need it. I bummed a Sun unit from a co-worker and in return I'm loaning him my tire irons for a chore on his Suzuki V-Strom (sp?) thing...   Monte

[Motu]

After decades of using many sorts of timing lights in my job - self powered has been my light of choice the last few years.One induction hook up and you are done.The advance lights are good if you have TDC only marks,or want to set max advance and are only given idle speed marks.

[drewboid]

The Sears light works for me - for the past 20 years at least. Inductive pickup and metal case. I even use it to time the R60/2 with magneto ignition and a 6-volt system. Of course for that I use a car's 12 volt battery rather than the bike's system to power the light.

[montmil]

...Of course for that I use a car's 12 volt battery rather than the bike's system to power the light.

Which reminds me... I forgot to mention that the BMW manuals state that an alternative battery is to be used; not the battery in the bike being timed in.

Monte

[Justin B.]

I have always clipped the light to the vehicle's battery.  I wonder why they feel a separate power source is required?

[nhmaf]

I think that the light draws a fair bust of current when it is triggered, and as such injects noise into the electrical system, which could in turn affect the stability of the timing signal that you are trying to measure.
I think that if one has a good, dependable battery that is starting off well charged, it isn't likely as to be an issue, but the sensitivity of the ignition control unit could be a factor.    With larger car/truck batteries, the current pulses are small compared to the battery's current ability and energy capacity, also.    

I think that my timing light actually came with an AC/DC adapter so I can run it off any nearby wall outlet in the garage.

[Bob_Roller]

If I am running the bike for testing purposes, I connect a Sears automotive charger to the battery while doing a carb synchronization, or timing check, it shows about a 5 amp charge during idle testing.

[Yikes]

After reading the comments, I think I will follow the advice on borrowing a timing light for the limited times I will need it.  My neighbor who has the light is a retired machinist and loves to tinker with my bike.  He has given me a  lot of good advice over the last couple of years.

Thanks to all for the comments.

JM