old honda b7.5 no spark

[loiner1965]

right.....first four stroke to tinker on
just picked up and previous owner said it started but wouldnt run long etc
quick look at it and they is no spark at the plugs
this is an early model with no oil light but a stop push switch in its place
am i missing something simple as a neutral switch inhibitor etc.....sorry for being vague but its dark now and i just wanted some good advice about checking things before i needlessly start stripping etc

 

[Sea Rider]

There are 2 issues here, the engine previously ran but not for long and now engine doesn't produce a spark. Check kill cord switch is mechanically operative, that's opens/closes elecctrically the engine's circuit.

If ok, you could have missing magnets on flywheel, crank key flywheel out of timing sync, kaput Exciter Coil, CD, Ignition Coil, Plug Cap, even plug assuming ti's a one cylinder engine. Stripping engine down will not cure it as it's not a mechanical related issue unless flywheel related ?

Happy Boating

 

[loiner1965]

no kill cord fitted....
testing the coil .......reading between both plug leads ( caps removed) is.........14.54 ohms meter set on 20k
reading between positive of coil and earth lug................... 021 ohms meter set on 200 ohms
obviously the coil as readings weather they are within specs i am not sure but i would have thought it would still spark
might try flashing a 1.5v across the coil to see i plug sparks
tomorrow i will remove flywheel and see if charging coil is rubbing on magnets or if anything else in there is amiss

 

[Rick Stephens]

Most of those also had a neutral start switch on the starboard side of the engine. The shift shaft has a lobe with a line on it that lines up with the front of the switch housing when the unit is in neutral. That lobe is clamped to the shift shaft and can move easily if loose.

Rick

 

[loiner1965]

no neutal switch.....will remove flywheel and inspect coils and magnet in there....only issue is removing flywheel....
cannot remove nut lol