Centrifigal clutch placement.

Kenny'sID

New Member
Jul 7, 2016
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FL
This may not even be an issue but I need to be sure before I muck something up.

When I have the Centrifugal clutch installed on the shaft, there is room for it to slide in and/or out on the shaft. Do I need to shim that somehow so it cannot slide back and forth or just install the key and shaft bolt and let it ride? Or is the play designed so it can ride and find it's perfect place in line with the chain?

Also, before I cut adjustment grooves in the engine mounting plate, how tight should this chain be? Been awhile since I've even messed with a bike but I'm thinking no slop at all yet not cranked down so thight it's hard to turn. Is there a simple way to gauge that?

415 chain setup on a hybrid trike (front hub 1000w) w/rubber spoke mount and small 3hp (79cc) predator 4 stroke engine because the gas engine is mainly a back up. .

Thanks for your help.
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
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memphis Tn
The clutch should have a setscrew to secure it on the shaft
Proper chain slack is 1/2 to 3/4 inch. No more, no less.
Too tight a chain on a clutch will quickly trash the bushings and lead to failure.
Proper chain slack lets it run with least mount of drag.
 

Kenny'sID

New Member
Jul 7, 2016
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FL
Thanks Mania, I was going by the tension instruction for the bike chain in standard bike application and they said tight, but I recon it's different for motors/clutches.

No set screw.

Still not certain what's going on here, but looks like this clutch won't work for this application. I'm guessing there should be no space like I mentioned at all once the retaining bolt is installed?

I ordered it because it was the only one on ebay that would take a 415 chain and fit a sideshaft 4 stroke. Even then I had to order a 3/4 to 5/8 adapter sleeve to make it work and the key is way too big. So I guess the 79cc predator is just not going to wok for this, even thoiugh they do use them on bikes..

They had the 6.5 HP predator on sale so just grabbed one of those, as this clutch was just for that engine. Way too big for the bike laws here in FL but I'll just have to try to get around that somehow.
 

Tony01

Well-Known Member
Nov 28, 2012
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sf bay area
Use a 3/4" max torque clutch for the 212. Buy a black spring with 6 heavy shoes so you can tune the takeoff. The clutch will slide maybe .200" so you may want to either get spacers or just use the setscrew on the clutch hub and have the crankshaft bolt in for safety.

Also be aware that the 212 will have a lot more power than the 79cc, and it will tear up that rag joint spokes sprocket. If you wanna go back to cheap I suggest getting the 79cc predator and running the 5/8" clutch on it. The 212 will require some mods and a stronger driveline.
 
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Kenny'sID

New Member
Jul 7, 2016
16
0
0
FL
Use a 3/4" max torque clutch for the 212. Buy a black spring with 6 heavy shoes so you can tune the takeoff. The clutch will slide maybe .200" so you may want to either get spacers or just use the setscrew on the clutch hub and have the crankshaft bolt in for safety.

Also be aware that the 212 will have a lot more power than the 79cc, and it will tear up that rag joint spokes sprocket. If you wanna go back to cheap I suggest getting the 79cc predator and running the 5/8" clutch on it. The 212 will require some mods and a stronger driveline.
Good info, thanks Tony.

I went with the rag joint jsut for that reason...figured it could handle the 79cc, but over all, wish I'd a gone to the solid spoke mount now, my options would have been better.

Actually I found the 212cc on sale so went ahead and ordered it since the original clutch was for that. Then Gasbike offered me a clutch from one of their 2 stroke kits that would fit the 79cc so I figured WTH, and grabbed that too.

So I'll probably end up with the smaller 79cc and rag joint for now, and see what kind of speed I can get from it. See, I live on a stretch of dirt road and this front hub 1000w doesn't fair well with that so the gas was really only intended as a backup for breakdown and to get me off the dirt road in conjunction with the electric power train.

Then there is the fact Fl only allows a 49cc and even that has to be registered so I was hoping to get a 49cc sticker for the 79cc, get it passed inspection, then put what I want on there if I need to. But first I'll run it and see if they are even going to stop me at all, some cops/cities don't care.

So lots to consider, but if at all possible, I like the idea of the 212cc eventually (especially since I will already have it and it's clutch. Is the spoke mount all I need to concern myself with or does it need to be beefed up elsewhere for the 212cc?
 
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MEASURE TWICE

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Jul 13, 2010
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CA
http://www.ebay.com/itm/5-8-x-3-4-x...ducer-Sleeve-Bushing-Sheave-Key-/251943004476

The above is just one of many that have the sleeve adapter with the non-square shape key included with it, if I'm right. If you use the magnify zoom feature on the page look at the end of the key and you see the y axis taller than the x axis on the special key. It still might be hard to see, but it is just marginally non-square to be just right for use with the sleeve.

There are some sold separately, the special shape key by itself also probably too.

I myself have tools (not a mill and lathe wish), that I just for a small key special shape custom just get key stock large enough to modify to what I need at savings, but using my own time.

I needed the very last bit of keyway slot in the crankshaft to use on my Briggs engine for a clutch and found the section nearest the crankshaft case wall rounded up at an angle. Dang took a while to grind the shape of the key, and when installing it on the shaft how to get it to stay put while assembling, but then it was as usual after figuring it out.

Dremel & Die grinder with various cutter and grinders wheels, files and sandpaper you can do the same as sold parts on Ebay.

The crankshaft if it does not have threads at the end you can make them, but I was hesitant as if it is screwed up then what do you do. The Briggs I have did not have on the 5/8 shaft any threads, but I was able to drill and tap it myself. Use the best taps or just forget it. Many from you know where for cheap are good for aluminum maybe?

The use of a clutch that uses the tapped threads at the end of the shaft with a bolt, flat washer, and split lock washers to keep it there, even if the thread direction self tightens with engine rotation, can be I hear used without set screw on the keyway. Then I've heard it tracks and find the best spot. I've never seen it in real life and I just decided to use everything. I also did make specific shim washers to get the clutch to be solid no play left or right. Just be sure the shim washer rotating along with the crankshaft does not scrape on the stationary bell sleeve while the shoes are disengaged at startup and the bell is still when idling.
 
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curtisfox

Well-Known Member
Dec 29, 2008
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minesota
You can by ( have to order it ) a 3/16" x 1/4" key stock. Then you can run the clutch, also you can get 5/8" locking collars, ( ACE has them ) if there is room on the shaft.........Curt
 

MEASURE TWICE

Well-Known Member
Jul 13, 2010
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CA
https://www.grainger.com/product/GRAINGER-APPROVED-Keystock-5VA15

I am getting this from Grainger for the sleeve I already had from them. With tax total is $3.11 in CA for store willcall pickup. The stock I'll cut myself to key length 5/8 from the 12 inch length. This from the 3/16 x 1/4 over size by 0.003 so you may have to file it some, but better than loose. There is another part for under size, not sure why you would want that, except it says does not require filing? With the adapter it would seem important to have as tight a fit as possible.

https://www.grainger.com/product/DAYTON-Bushing-2X774?searchBar=true&searchQuery=2x774

The part I already got for the sleeve bushing reduce 3/4 to 5/8 came 3 in a bag at less than 9.00 for a pack of three.

The picture shows if square 3/16 x 3/16 key is used. Not useful at all without the rectangular 3/16 x 1/4 key.

If this old Top Man 3/4 clutch is no good, I'll see for around 32 dollars a Max Torque Ss1258 Clutch on Amazon from seller Lionparts_Powersports with free shipping. This is the kind without the built in key. They I feel are more versatile. If I do have to get that clutch I can save the adapter parts for another time as this Maxtorque is a 5/8 clutch with 12 teeth.

I have the belt type Maxtorque Clutch and it is really good, but chain is easier for the modification to use a different engine. I'll have the option with the mod to go back and use the smaller engine if necessary. Just making the bike more powerful with the 3.5hp over the older worn out some 3hp Briggs.

https://www.amazon.com/gp/product/B...fl_title_11?ie=UTF8&psc=1&smid=A30UY5IZ1VQRNY
 

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