recomend a timing light with 2 stroke tach operation?

[bzajdek]

will be needing a timing light for adjusting my 1986 Mariner 90hp outboard. The motor is a 6 cylinder without distributor but has adjustable timing and advance. I would like the light to have a tach, so not the simplest one but not to complicated and be very bright as the timing has to be done under load with the boat in the water(Yes I will be moving and have a helper with the cowl removed, just a bit scary). Can anyone recomend a good timing light with these features that will not break the bank(about $150).
Thanks

 

[Yepblaze]

Re: recomend a timing light with 2 stroke tach operation?

I would think you maybe could set the timing in your driveway.

Start by verifying TDC.

Attach light to #1

Remove and isolate all spark plug leads (with load), so it can't start!!, jump starter solenoid at full throttle in gear.

I like my advance timing light, but I think I had to halve (or double) the readings for 2 stroke last time I did something like that.

 

[Silvertip]

Re: recomend a timing light with 2 stroke tach operation?

Setting the timing in the driveway is fine for idle timing but full advance timing under load must be done -- well -- under load. One way to do this is to keep the boat on the trailer and have it well tied down at the bow and stern. Back in, do the testing. The boat will not push the car. Just make sure you do this at a ramp that is not busy and preferably one that you won't get into trouble because you are blowing a hole in the bottom and sucking up sand. This is not a centrifugal advance mechanism so the engine doesn't need to be at maximum revs - just maximum load (they are not the same).

 

[JustJason]

Re: recomend a timing light with 2 stroke tach operation?

The way I do it is by disconnecting the throtle from the timing arm linkages. I'll run the engine at idle, then push the timing arm to the adjustable stop and check the timing. I adjust it to 2 or 3 degrees shy of the maximum spec, then put it all back together. When the motor is in the water running at max rpms the timing will advance that last extra couple of degrees, and be on the money.

I don't know about you guys, but i'm not a fan of having my face and hands a foot from a flywheel spinning at 3 grand, let alone 6.

 

[rodbolt]

Re: recomend a timing light with 2 stroke tach operation?

I use a light from ferret instruments,model 84, and a trusted helmsmen thats not on my life insurance policy.
ONLY way to check WOT timing is AT wot full load. you can water test it,dyno it or use the reccomended test wheel.
at the end of the day it has to be done at full throttle,full load and to spec.

 

[Rocky_Road]

Re: recomend a timing light with 2 stroke tach operation?

will be needing a timing light for adjusting my 1986 Mariner 90hp outboard. The motor is a 6 cylinder without distributor but has adjustable timing and advance. I would like the light to have a tach, so not the simplest one but not to complicated and be very bright as the timing has to be done under load with the boat in the water(Yes I will be moving and have a helper with the cowl removed, just a bit scary). Can anyone recomend a good timing light with these features that will not break the bank(about $150).
Thanks

MATCO makes a nice digital advance/tach timing light that will work for a 2 cycle engine. I use mine to set timing...read RPM...check advance timing...measure centrifugal advance...even measure vacuum advance. The model that I have is the MTL4186, and these show up on eBay all of the time. It is a professional tool, but can be had well under your stated budget.

Happy boating!

 

[4JawChuck]

Re: recomend a timing light with 2 stroke tach operation?

This one is cheap and works well, it has all the features you want.

http://www.autorepairmanuals.biz/site/573683/product/EQUUS5568

I have a SnapOn with a digital rpm/timing offset display that does not have a 2 cycle switch and while it works I have to be careful of cross spark causing display confusion at WOT under load.

...and yes I do this at WOT on the water with the hood removed while hanging off the transom, get a driver you can trust. I have found it needs to be checked under actual operating conditions to be accurate, if you find your timing jumping all over the place make sure the timing linkages are in good shape. Most I have seen are so worn the timing is all over the place at WOT from vibration...even motors only a few years old. A dab of silicone grease will help quell vibration until you replace the fittings if yours are worn.

 

[Chris1956]

Re: recomend a timing light with 2 stroke tach operation?

If you have a test tank and test wheel, setting the max timing advance with the motor running is a safe, standard procedure. It is very dangerous (and unnecessary) to have the boat in the water, with a prop installed, and run it at max throttle to set timing.


It is just as accurate to set the Max timing with the motor cranking, but not running. Simply remove all spark plugs but #1, and reinstall the plug leads and ground all the plug electrodes. Now set the throttle wide open, and adjust the timing with the motor cranking.

 

[rodbolt]

Re: recomend a timing light with 2 stroke tach operation?

most engine manufacturers have a service manual procedure to get it close,sometimes even dead nuggets.
however most also say to verify it at WOT and its normal load.
this means either test wheel,dyno or hanging off the back.
I prefer the test wheel or dyno method personally but occasionally I have to use the hang out the back method.