OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions on Other Engines Scott Bonnar utility

I just bought this from the scrap yard for $30...
Something to play with, good compression, no rust. no blade disk.
I see it's 155cc, a model 31 1958-9

speedy

Looks like a good find Speedy. Aside from the missing bits it seems very tidy and original without much wear.

I’m thinking it might have had a minor mishap relatively early in its life and never been put back together. The lack of wear, particularly on the deck, seems to point that way.

Fingers crossed, it’ll be fairly straightforward to recommission.

I put another wheel on the back as the original fell apart. Took the flywheel off, someone put a atom electronic ignition in. I can't get a spark. I soldered the wires and they are wired right... Maybe coil shot.....
The height adjusters work....and it has good compression.
speedy

That's a good score for $30 Speedy ,as it is I could see SB fans bidding online for something similar and bidding over a $100.

If you have a Multimeter you could check the coil ,I would remove the coil and clean all the earth connections and wire
connections and check the spark plug connector to the lead and the other end of the plug lead.

A Honda coil may fit but don't buy cheap Chinese coils from online, as I have found they are useless.

Original New old stock coils are available but are expensive when it's overseas.

I've been pinching all my Honda coils for Vintage mowers but have now fixed the Honda mowers by using a Tecumseh
coil on the Honda E core.

Cheers
Max.

Hello Max
I remember your recent sermon on had to rework a coil, and I was bewildered....... thinking, gee I'll never have to do that.
I set multimeter on 20k ohms, and tested coil, got reading 3.84 so coil should be OK.....
The guy soldered a piece of 3 core electrical wire as the plug lead.... plenty of copper....
I should have more EI modules.. to test. And I tried to check the flywheel air gap, a bit tricky through that little window hole.
I soldered the wires together , instead of a piece of bandaid. But people use what they got.....
But I'll do what you said. Thanks
speedy

Hi Speedy,

The Honda and Wico coil aren't going to fit this early coil ,I thought it may have had the later coil but is the same
as the Rotomo and early Pope.

My old Pope coil was 3.93 so your coil looks good at 3.84.

The air gap on all my coils the same as this SB one can't be adjusted as the E core is pinned to the alloy plate, The
Pope I converted to pointless ignition had one pin hole drilled in a different position than it should have so the air gap
was less than normal on one side so I removed one metal pin and moved the coil on that side and then
tightened the mounting bolt.

When I adjusted the air gap, you can move the coil closer to the flywheel with the flywheel removed ,then fit the flywheel
and turn the motor over and if you can hear and feel the coil rubbing on the magnets just remove the flywheel and look
at the mounting position of the E core and adjust it back a little and tighten the bolt and fit the flywheel and turn the flywheel
so you know the magnets aren't rubbing. If you scribe a line when the coil rubs you should be able to adjust the coil back
006 - . 010".

I usually just check where the pins are in the core with these coils and if both are drilled in the same position and the
core isn't rubbing it should be ok.

I haven't seen this early type of coil work with an E module but I know the Atom modules were different for different coils.

If there is still no spark after working on the mower you can fit points back or rework the E core to take a later Victa coil.
( a later Victa points coil and a Powertorque module can be used)

Cheers
Max.

Hi Speedy,

When I look up the Blue Atom Module it works the same as a Powertorque module so may not work on the early coil.

The instructions with the Blue Atom module say not to install them under the flywheel ,so the first thing to try is moving the module.

I've heard some people say the Brown Atom Module will work others say the Pink Atom Module works and others
say the Kawasaki 2 wire Module will work.

Usually the white is the earth but no harm in reversing the wires to see if there are better results.

Cheers
Max.

I mounted the atom outside , and connected the wires..... ready to go but something happened.
I lifted mower into boot to take to Bolt Shop to get top and bottom nuts.....
Then when I tried to turn crankshaft round, it was hitting a stop......guess I'll have to take motor apart to see....
I put my endoscope in the plughole... to have a look at bore and piston.... Those scratches are from me with a piece of wire feeling that hole in the piston...
Piston pretty clean, bore has a burn patch..... but ok.
I'm getting tired of it...
speedy

got the flywheel turning.... and the atom didn't fire a spark mounted outside. I have two other modules to test...
speedy

Hi Speedy,

The hole in the piston looks like it's in the centre so looks like it's ..part of the machining process when they make the piston.

Yeah I was thinking the blue module and a Victa PT module would not work.

Cheers
Max.

All problems solved Max, I sold it to a cousin......in law
speedy

It's a rare mower Speedy ,harder to find than a model 1 Rotomo ,hopefully it will be restored.

yes a ODK member