Anyone With Measurements For Honda/Clone Engines?

#1
Hi. I'd like to install a billet flywheel onto my EX-17 Robin. However, the vendors I've contacted don't have aftermarket 'wheels for it. No one knows if the Honda/clone flywheel will fit any Robin engines.

If someone out there can post specifications on Hondas or clones, I can compare them with Robin engine flywheel measurements.

The Robin EX-17 engine flywheel

1-piece mounting plate and fins;

2.36" thick, including fins;

7 lbs. in weight;

7.0625" in diameter;

keyway is .125" wide;

The Robin engine's crankshaft is tapered;

Its machined nose is 1.125" long;

Total length of shaft with threaded tip is 1.93" long;

At its base, the machined shaft is .97" diameter;

At the nose of this machined surface, it is .79" in diameter;

The shaft's half-moon key is .11" wide.

Thanks for any information you can give.:thumbsup:
 
#3
Thanks for your offer, man.

Yes, that Robin wheel IS heavy, lol. When I removed it, the Robin seemed VERY light.

In fact, with flywheel, pull start, tank and air cleaner removed, my EX-17 weighs about 20 lbs.!:thumbsup:
 
#4
Heres some pics. Please use as a guide only, and judge accordingly. I would say you could make it fit with a coil bracket and some machining. You may want a gx200 coil.
 
#5
More pics
I am not sure if the keyway measurement is 100%.
IMO if you plan to do lots of modification, you may be better off starting with a clone.
 
#6
Thanks!

Wow!!:thumbsup:

EXCELLENT descriptions!

Yeah, keyways are hard to measure. The key was MUCH easier to gauge.

Thanks again, man.
 
#7
r_chez, can you measure the woodruff key's thickness? Yours look thicker than mine. If it is, then a new, thinner keyway would have to be machined onto the new flywheel.

Too bad you couldn't measure a crank that was still in the block. I'm having difficulty comparing my crank measurement(length) with yours..
 
#8
r_chez, can you measure the woodruff key's thickness? Yours look thicker than mine. If it is, then a new, thinner keyway would have to be machined onto the new flywheel.

Too bad you couldn't measure a crank that was still in the block. I'm having difficulty comparing my crank measurement(length) with yours..
About the 7/8th mark you can see where the seal rides on the crank,hope that helps.
 
#14
Would it be the same as the 4th picture?
No, that's the keyway(groove). The woodruff key is several ten-thousandths of an inch smaller. It is much easier to measure. I know the Robin key is smaller than the Honda's. I just wanna know the difference.

Motra, you might be right about that timing difference.

Thanks for taking more time, r_chez_o8.

What I'll prolly do is buy a used Honda engine locally, hopefully for cheap. If its pulley bolts down onto the Robin's shaft, then I'd consider machining a thinner keyway. If ignition timing is normal, THEN I'd buy a Honda billet 'wheel for the Robin.

If the used Honda flywheel does NOT fit the Robin, then I'd prolly run it w/governor and rebuild the Honda engine for high performance.
 
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#18
FYI, the aftermarket flywheel for the Honda/clone engine will definitely NOT fit my Robin EX-17 engine.

The Robin's tapered shaft is too thick, so the ARC flywheel that I have will not seat.

Besides, the Robin's key is too thin. A new keyway would have to be machined on the ARC flywheel.

Case closed.
 
#19
I have a subaru 7hp motor .... I got a billet arc rod and flywheel for it ...I'm not sure if the ex21 flywheel will work on your motor but I don't see why not if ex17 parts are interchangeable with ex21 parts. I will post a pic for u .
 
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