Pull Start Cup for JR Racecar Flywheel
A 3hp Briggs I/C that's been gone over pretty well.
http://www.oldminibikes.com/forum/project-logs/74295-boardtracker-build.html
http://www.oldminibikes.com/forum/project-logs/74295-boardtracker-build.html
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I've read this thread several times chain, but I'm not familiar with a JrRacecar brand billet flywheel. Some pics would be very helpful. Most flywheels I've seen still use the standard Briggs starter cup that is attached to the engine by the same large nut that holds the flywheel on. Or on the older 5hp engines they used the start/clutch.
Matt
Matt
I assume this is going to be a race only engine, as your flywheel doesn't have any cooling fins. This type of flywheel can only be run in short bursts as any longer, and your engine would overheat, unless you have a bolt on fan for it. As far as starting goes, it looks like it should work with either of the standard Briggs start setups. There is a pic of the different type crankshafts below. The one with the long snout uses a start/clutch (I didn't have one handy to take a pic of). but I did show a pic of it next to the type of recoil it uses. The crank with the short snout uses a metal cup on the front of the flywheel, and I showed a pic of it sitting next to the type of recoil it uses. Hope this helps.
Matt
Matt
Judging by your work and depth of this project, I'm sure you're more skilled than I in answering that question.
But thinking about it, that cup is some fairly thin stuff. I might benefit to have the flanges sitting in some countersunk holes in the flywheel to keep it from working. Certainly the bolts would have adequate shear strength, but the recesses keep it from working, which would cause the bolts to loosen.
Could you countersink your flywheel to accomodate those flanges?
But thinking about it, that cup is some fairly thin stuff. I might benefit to have the flanges sitting in some countersunk holes in the flywheel to keep it from working. Certainly the bolts would have adequate shear strength, but the recesses keep it from working, which would cause the bolts to loosen.
Could you countersink your flywheel to accomodate those flanges?
So I dug through my parts and found a pull start cup, it has 2 nipples where it should attach to a flywheel but my flywheel doesn't have indents. Could I just smooth the nipples flush and expect the torque of the nut to be enough to hold the 2 together and allow pull start?
Matt