Setting points

[Big Woody]

Anyone have a good way for setting points on the old saws like my 090. Manual says to use a dial indicator through the plug hole to set at 3 mm from top (BTDC) and a light box hooked through the ground wire to tell when points close. The dial indicator and light used to be sold in a tool kit but not sure if still available.

I'm sure some of you experts have a good way without the special tools or with something you rigged up on your own.

Enlighten us.

Thanks

 

[HiOctane]

Im not familiar with this model,but there is probably a mark on the flywheel and one on the crankacase.Have an ohmeter,connect it to the lead from the points and other to ground.Turn the flywheel slowly and when the points are JUST beginning to open(the needle ohmeter will move to the other end of the scale ), the marks on fly and case should align.Points setting must be .015

 

[lesorubcheek]

Old David Bradleys were like this also. No marks on the flywheel or case or anywhere. Procedure is to measure the piston from TDC and set points so they begin to open based upon this position of the piston. Cheap dial calipers are out there that can measure depth. This is what I use on the DB. Just make sure you're on the correct side of TDC (either before or after as indicated in instructions) as this is a BIG difference. Most ignition timing is before TDC.

Good luck,
Dan

 

[Al Smith]

Anyone have a good way for setting points on the old saws like my 090. Manual says to use a dial indicator through the plug hole to set at 3 mm from top (BTDC) and a light box hooked through the ground wire to tell when points close. The dial indicator and light used to be sold in a tool kit but not sure if still available.

I'm sure some of you experts have a good way without the special tools or with something you rigged up on your own.

Enlighten us.

Thanks

You must have the same info as myself.First of all,I've never seen the big 090 apart.However that proccedure is about the same as staticly timing any engine.Set the points[.012 to .016] air gap at .008 to .012 set the points to open at the timing mark by moving the armature plate.If it tries to pull your arm off when you start it,it's too far advanced.

 

[Simonizer]

2.5 mm BTDC does not affect performance and makes it easier to start. This saw can be a real bear to pull over with the ignition advanced too far. Dial indicators are cheap and/or can be borrowed. You don't need a light box, just a meter with an audible continuity function. Cheers.

 

[Big Woody]

OK. great. Thanks for the information.

But how do you attach the dial indicator to the head. It looks like the stihl tool had a fitting to screw into the plug hole and the indicator slipped inside of that. Without that fitting how are you fixing the gauge so it doesn't move relative to the head.

 

[Simonizer]

OK. great. Thanks for the information.

But how do you attach the dial indicator to the head. It looks like the stihl tool had a fitting to screw into the plug hole and the indicator slipped inside of that. Without that fitting how are you fixing the gauge so it doesn't move relative to the head.

Most dial indicators have a magnetic base. Clamp a piece of angle iron to the saw and adjust your indicator as parallel to the bore as possible so as to receive an accurate measurement. The force required to push in the indicator plunger is very slight so this will give you excellent results.