Flywheel magnets

markus

Well-Known Member
#22
Hs40 55388e ser#5093b lighted flywheel
#33660a or 33660c would be good part numbers for HS specific lighted flywheels in the mid 1970's, that can be a tall order to fill as the sales mini bikes dropped big time in the mid 70's and there was not much use in the industrial world for lighting systems like that on small frame engines. So there are not to many of them floating around. You can find 2 styles of them as the first versions (that actually were on the early built HS50's) were aluminum with the cast and pinned in magnets and by end of 1974 they went to what you have currently....as Far as I know there was not a part number change, or if there was Tecumseh made it disappear as they made the AL one obsolete and the Steel was direct fit.

can your magnets, for the most part be salvaged? I know you said one broke but do they have pull/attraction and would you be able to still glue the steel spacer plates on like seen below (this is one I had to fix few years ago, magnets and spacers came come free as pull of the magnet will overtake the 35-45 year old thin film of glue eventually):



If so it would be possible to transfer them from your existing wheel to a standard non lighted wheel donor. The wheels themselves are the same, its the magnets (and spacers on lighted ones) that make the difference in the systems. If doing that you would need to be precise in spacing and magnet orientation, but if you have magnets still on your current wheel, you can start by making say a cardboard pattern off that one keeping the keyway in mind (more important than the lighting is that the ignition coil will fire as hot as it can). I retrofit lighting systems into late model electronic ignition flywheels (different system than yours), and I made templates for myself so I can get the magnets spaced and set properly. Doing it that way has worked very well to get the magnets where I need them to be.

As far as a broken magnet, If that is the case, I would put damaged or weakened ones in the charging field area (away from or right after the coil fire happens).

Donor non lighted wheels can be found, #33695b is one with no ring gear, and the easier to find 33701b has a ring gear (they are just pressed on and come off easy if you want or can simply be left there if you don't care-they fit under the shroud either way) Just pop the 2 ignition magnets off and you have a fresh wheel to work with.

Please note that you cannot use your current lighted stator/magneto assembly with the non lighted magnets....there is a difference in depth of the magnets so it will not fire due to imporper air gap. the magnets (and spacers for lighted in your case) do need to match so bolting that onto your engine just to run will not work without also changing to the non lighted magneto assembly.
 
#23
#33660a or 33660c would be good part numbers for HS specific lighted flywheels in the mid 1970's, that can be a tall order to fill as the sales mini bikes dropped big time in the mid 70's and there was not much use in the industrial world for lighting systems like that on small frame engines. So there are not to many of them floating around. You can find 2 styles of them as the first versions (that actually were on the early built HS50's) were aluminum with the cast and pinned in magnets and by end of 1974 they went to what you have currently....as Far as I know there was not a part number change, or if there was Tecumseh made it disappear as they made the AL one obsolete and the Steel was direct fit.

can your magnets, for the most part be salvaged? I know you said one broke but do they have pull/attraction and would you be able to still glue the steel spacer plates on like seen below (this is one I had to fix few years ago, magnets and spacers came come free as pull of the magnet will overtake the 35-45 year old thin film of glue eventually):



If so it would be possible to transfer them from your existing wheel to a standard non lighted wheel donor. The wheels themselves are the same, its the magnets (and spacers on lighted ones) that make the difference in the systems. If doing that you would need to be precise in spacing and magnet orientation, but if you have magnets still on your current wheel, you can start by making say a cardboard pattern off that one keeping the keyway in mind (more important than the lighting is that the ignition coil will fire as hot as it can). I retrofit lighting systems into late model electronic ignition flywheels (different system than yours), and I made templates for myself so I can get the magnets spaced and set properly. Doing it that way has worked very well to get the magnets where I need them to be.

As far as a broken magnet, If that is the case, I would put damaged or weakened ones in the charging field area (away from or right after the coil fire happens).

Donor non lighted wheels can be found, #33695b is one with no ring gear, and the easier to find 33701b has a ring gear (they are just pressed on and come off easy if you want or can simply be left there if you don't care-they fit under the shroud either way) Just pop the 2 ignition magnets off and you have a fresh wheel to work with.

Please note that you cannot use your current lighted stator/magneto assembly with the non lighted magnets....there is a difference in depth of the magnets so it will not fire due to imporper air gap. the magnets (and spacers for lighted in your case) do need to match so bolting that onto your engine just to run will not work without also changing to the non lighted magneto assembly.
#33660a or 33660c would be good part numbers for HS specific lighted flywheels in the mid 1970's, that can be a tall order to fill as the sales mini bikes dropped big time in the mid 70's and there was not much use in the industrial world for lighting systems like that on small frame engines. So there are not to many of them floating around. You can find 2 styles of them as the first versions (that actually were on the early built HS50's) were aluminum with the cast and pinned in magnets and by end of 1974 they went to what you have currently....as Far as I know there was not a part number change, or if there was Tecumseh made it disappear as they made the AL one obsolete and the Steel was direct fit.

can your magnets, for the most part be salvaged? I know you said one broke but do they have pull/attraction and would you be able to still glue the steel spacer plates on like seen below (this is one I had to fix few years ago, magnets and spacers came come free as pull of the magnet will overtake the 35-45 year old thin film of glue eventually):



If so it would be possible to transfer them from your existing wheel to a standard non lighted wheel donor. The wheels themselves are the same, its the magnets (and spacers on lighted ones) that make the difference in the systems. If doing that you would need to be precise in spacing and magnet orientation, but if you have magnets still on your current wheel, you can start by making say a cardboard pattern off that one keeping the keyway in mind (more important than the lighting is that the ignition coil will fire as hot as it can). I retrofit lighting systems into late model electronic ignition flywheels (different system than yours), and I made templates for myself so I can get the magnets spaced and set properly. Doing it that way has worked very well to get the magnets where I need them to be.

As far as a broken magnet, If that is the case, I would put damaged or weakened ones in the charging field area (away from or right after the coil fire happens).

Donor non lighted wheels can be found, #33695b is one with no ring gear, and the easier to find 33701b has a ring gear (they are just pressed on and come off easy if you want or can simply be left there if you don't care-they fit under the shroud either way) Just pop the 2 ignition magnets off and you have a fresh wheel to work with.

Please note that you cannot use your current lighted stator/magneto assembly with the non lighted magnets....there is a difference in depth of the magnets so it will not fire due to imporper air gap. the magnets (and spacers for lighted in your case) do need to match so bolting that onto your engine just to run will not work without also changing to the non lighted magneto assembly.
 
#24
All good information I don't need a flywheel mine is fine the photo is exactly the flywheel I have I need one magnet. Will it create spark if I put it together with 5 magnets?
 
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