Looking for info on flywheel delete

The.MiniTard

The.MiniTard

Member
#1
#1
I have an older engine that has points and I would like to perform a flywheel delete. My only problem here is that I cant find any information on this mod. I've searched the forums and all ive come up with is one thread that doesnt really talk too much about what he uses in place of the flywheel after the flywheel is removed. Anybody have any information on the flywheel delete mod?
 
Street Smart

Street Smart

Well-Known Member
#2
#2
Not sure I`ve ever seen a motor run with out the flywheel. It kinda needs the inertia of the flywheel to run. Not to mention how you would trigger the ignition.
 
The.MiniTard

The.MiniTard

Member
#4
#4
maybe ive misunderstood something then. I was under the assumption that an older engine that has points doesnt use the fluwheel to trigger the spark
 
Street Smart

Street Smart

Well-Known Member
#5
#5
The.MiniTard said:
maybe ive misunderstood something then. I was under the assumption that an older engine that has points doesnt use the fluwheel to trigger the spark
Click to expand...
Old or new the flywheel tells the ignition when to fire.
What was the theory of why you would want to run an engine with out a flywheel?
 
The.MiniTard

The.MiniTard

Member
#9
#9
no, there is a post on here. Its really old but a guy did it. i dont know if the motor ever went on an engine but he did it. let me find the post and link it
 
delray

delray

Well-Known Member
#11
#11
if your still going to use it on a minibike? not sure how well the engine will run without a flywheel. kind of need that to obsorb the energy from the clutch or torque converter spinning. hey what do i know.........just a gearhead.
maybe video would nice at 3000 rpms:rolleyes:
not try to make fun of it,but i am just say you might need some safety glasses:blink:
 
delray

delray

Well-Known Member
#12
#12
here is something maybe to look at when removing the flywheel and using a different ignition. you still need something hanging on the crank.
video is little off from what you want to do,but interesting to watch how they built it .
https://youtu.be/JgBk5GEC9kc
 
tmack1

tmack1

Member
#13
#13
Flywheel delete, a bit hard with modifying ignition. Rather a bunch of custom work including having a battery to run the spark. (The flywheel on old engines creates the voltage to make the spark)

Reducing flywheel weight, moderately common. Rev's faster. And if you're good with a dremel, can get rather artistic. Just watch you don't take too much off, and make sure you maintain "balance".
 
J

jim85541

Member
#14
#14
I lightened up a 750 Honda 4 cylinder years ago. had a 900cc bore kit, alloy rods, lightened alternator. running high compression, stiff valve springs. For it's time it was pretty fast. But, the engine did not want to keep spinning at low rpms. several drops in parking lots putting around as the engine would just not have enough weight to keep spinning and lock up tighter than a bulls ass in fly season. Lots of revs and slipping the stiff Barnet clutch, was the answer. On a small single cylinder engine like this I wonder with no flywheel if it would be rideable? Would need stiff springs in the clutch or TC to engage at high RPMS or a manual clutch. Might have to make a light weight alloy flywheel, play with weight until you got a balance between performance and rideability.
 
noseoil

noseoil

Active Member
#15
#15
Not really a very practical idea for a small single cylinder motor. It needs rotational mass to idle well & begin pulling, create a spark for ignition & run smoothly, all of these things.

I guess you might get away with a twin-lobe flywheel design to retain the spark for ignition, but if this was a good idea, someone would have most likely set one up to run like that already. Thinking it isn't worth the cost to do, but would be interested in seeing a practical application of the engineering & how the motor pulls at high rpms (model airplane engine).
 
65ShelbyClone

65ShelbyClone

Well-Known Member
#16
#16
The.MiniTard said:
https://www.oldminibikes.com/forum/...project-engine.html?highlight=flywheel+delete

this is the link to the thread. The users name is 65ShelbyClone
Click to expand...
The engine I used was a very old Briggs where the ignition was totally separate from the flywheel. It's all in that thread. I still have the engine, but it's all in pieces.

Deleting the flywheel for fun....well, it's not going to be fun. The engine will be really hard to start, prone to kickback, and easy to stall. The drag engine above with the tiny flywheel probably won't even stay running below 3000rpm.
 
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