Tecumseh small engine timing dial indicator tool

[creia]

Tecumseh OEM part # 670241
Does anyone have one that they would like to sell? If so, please send me a private message to discuss.
Thank you,
Michael

[bobodu]

I got a nickle I'll sell you for a dime....
Did that for years....then I bought a dial indicator at Harbor Freight and drilled a hole in a piece of wood and used a drywall screw to lock it in place.

[bgsengine]

I got a nickle I'll sell you for a dime....
Did that for years....then I bought a dial indicator at Harbor Freight and drilled a hole in a piece of wood and used a drywall screw to lock it in place.

thing about this particular dial indicator, it works through the spark plug hole , so you can set timing without removing head.

[bobodu]

Gottcha...

[Dale_W]

Curious, and you may already be thinking about this.

If you bought the harbor freight indicator, and re-purposed an old spark plug, could you build your own 670241?

I googled 670241 for sale. Plenty of hits. But when I drill down on the website, then they are out of stock. (shocking)

And the prices! crazy.

Let us know.

[bgsengine]

Depends on how good a machinist you are at building the adapters and offset flag.. you'd need to get it perfectly square to the spark plug hole.

[fixer5000]

IVE BEEN USING A LONG REACH MITITOYO INDICATOR MOUNTED ON A MAG BASE WITH A LOCKING FLEX SNAKE ARM FOR YEARS. WORKS SLICK EVERY TIME

[Arkie]

Depends on how good a machinist you are at building the adapters and offset flag.. you'd need to get it perfectly square to the spark plug hole.

Right, because the spark plug hole is not over the top of the piston, the indicator must have a offset leg when installed through the spark plug hole.

You can review timing procedures at about page 68-69 of the L-head service manual under ignition.
Timing is critical on the small Tecumseh engines and some of the 3.5 to 5 hp engines have a timing change in the specs per the serial number due to a change in the crankshaft throw. Get on the wrong timing specs for timing and it won't run correctly and if timing set too fast can result in breaking a rod. I've tried using witness marks on the coil legs for re-installing a coil for correct timing on the 3.5 engines and it's too critical to be in correct time. (just being in the ball park for timing is not good here)

I just pull the head and use a dial indicator on top of the piston and a ohmmeter to monitor the points opening and closing.

Stuff like this that helped cause Tecumseh engines to get bad mouthed by small engine mechanics and shade tree mechanics. Little more critical to work on as compared to other engines.

[Arkie]

IVE BEEN USING A LONG REACH MITITOYO INDICATOR MOUNTED ON A MAG BASE WITH A LOCKING FLEX SNAKE ARM FOR YEARS. WORKS SLICK EVERY TIME

Can you explain further so as I can review how this setup allows getting the offset INSIDE the cylinder area for the indicator probe tip?
I tried to search and review but could not find such.

[bgsengine]

IVE BEEN USING A LONG REACH MITITOYO INDICATOR MOUNTED ON A MAG BASE WITH A LOCKING FLEX SNAKE ARM FOR YEARS. WORKS SLICK EVERY TIME

Can you explain further so as I can review how this setup allows getting the offset INSIDE the cylinder area for the indicator probe tip?
I tried to search and review but could not find such.

I think he may be referring to an automotive ball joint gauge which has a similar design but mounts with a modified pair of vise-grips. You could mount that "snake arm" to a magnetic base too and lock it to hold dial indicator. But either way you'd have to have the head off. The tecumseh tool saves head removal

Can you explain further so as I can review how this setup allows getting the offset INSIDE the cylinder area for the indicator probe tip?
I tried to search and review but could not find such.

Tip of the tecumseh tool has removable contact tips , the flag is a flat piece of metal, one end you use a screw to fasten to the tecumseh tool after removing contact tip, then thread the contact tip into the other (threaded) end of the flag so it off-sets the indicator when the tecumseh spark plug hole is located over the valve area instead of direct shot to the cylinder, so you don't have to remove head... the flag locates the contact tip just far enough that it will contact the piston to set timing.