Clutch cable and clutch adjusting procedures.

[killercanuck]

That rattling at idle can indicate bad bearings in the "clutch-pad-holder-to-backplate". Those bearings like some grease too. Its just a pain to get it in there without gunking the pads. Or there could be a bad pressing of the bearing race and backplate(they're Pressed together w/China QC) causing slop.

One time a used bike I picked up had bearing lash so bad the large gear was actually carving into the cover. You can imagine what that sounded like, lol.

I just re-found these .gifs the other day after being lost for at least a year. Hopefully they'll help people visualize what's going on when you pull the clutch

*Note* - I did not make these. I found and saved them from this forum a long time ago. They got buried in my "Bike Stuff" folder.

-This shows the clutch side, and all its components. From the flower nut to those 52('ish) bearings. The parts that are pressed are the backplate and the bearing race:

This shows the Lever side, and shows the bearing that the shop gremlins can grab if you're not careful. But when liberally greased is doesn't fall out... so you know you need grease when?

This shows the Countershaft. It is adjustable inside the case for spring tension. ie, you can make the clutch pull harder(if its too light-not biting enough, even with the flower nut locked right down), or lighter(if its too tough to pull). This shouldn't be messed with until the absolute last resort. I only included it as a reference. Unless you're tweaking for racing then search Norm's section. And forget you ever saw this if you're still wondering what a flower nut is from the first gif...

This cutaway shows how everything works together. You'll notice that the whole actuation to release the clutch takes less than 2mm's to fully disengage:

I hope these help people get an idea of what's actually happening when you pull the clutch handle. But start with the basics first. If you've read this far into the thread, hopefully you've already tried all the previous advice first.

Quick Tip- Even with the Flower Nut(FN) off, the countershaft will seat itself and only go so far. That's something to think about when adjusting/setting your FN. Like if you set your FN too tight, the spring is already under tension, so that can make your lever very hard to pull. And if its too loose, it obviously just won't bite.

There's a nice line that'll give you great bite and a clean release without having to use 4 fingers on the clutch handle.

gl, have a happy clutch,
Greg.

 

[xenodius]

Wow! Thanks for all the info killercanuck. When I took this thing apart for the first time, the clutch plate behind the pucks had very little grease-- I greased it some more, but I'll take the pucks off and take it apart to be sure the bearings are properly greased. And I'll grease the bucking-bar bearing. =)

But even if I do that, it's still going to have the wobble that I showed in this video: http://www.youtube.com/watch?v=Vp6A3sqpEqQ
And if I don't fix that with a new shaft or clutch base, (plate behind the puck holder) won't that cause bigger problems shortly down the road?

 

[xenodius]

Everything is greased well, bordering on excessive, and when running I still have a rattling sound at idle and the scraping sound from the video, and a new development. Every once in a while, especially on small bumps, the engine goes HREEEEEESH and I have a brief, complete loss of power; I think this is the gears binding. It's only done it a few times. Either way, I'm not riding it again until I figure out what's wrong. I really hope it doesn't require any work on the countershaft... I don't have a good space at this apartment complex.

Edit: So to diagnose what's causing the wobble, should I take it down to the clutch backplate (behind the pucks) and see if it's bent, and if not, move to the countershaft post that's attached to?

 

[killercanuck]

oops, missed the vid earlier. Yea that's a weird wobble. With any luck its the pressing that's off kilter. Maybe once you get it off you can hammer on it with a pipe of the right diameter. Or you might have to take it to a shop(or friend) with an arbor press to get it seated true.

There's the option of replacing the whole thing. I could only find the completed assembly at gasbike, but they have them for $20 http://www.gasbike.net/bike-motor-part-complete-assembled-clutch.html

 

[xenodius]

Thanks again for the reply. But... the "pressing"? =/ I don't understand, yet I feel like the answer should be obvious.

Okay, so I tried to get the clutch base (plate behind the clutch pucks) loose, but even with the pedals locked and hammering my ratchet full-force, then trying my hand-impact on it, I can't loosen it. At all. I'm going out of town tomorrow morning so I'll have to try my hand on it later.

I figured I'd just replace the whole thing, but I'll take it to the small motor shop first and see what they say-- I do like living literally within sight of a small motor shop AND a bicycle shop. =)

 

[killercanuck]

by pressing, I meant the parts that are pressed together. The back plate and the bearing race, I forget how many tons of pressure they use, but its a lot.

For getting the nut loose, use the rope trick. take out your plug and feed some nylon rope in there with the piston lowered. When you crank on the nut, the rope will lock the piston and keep it from turning over. Make sure to leave some rope hanging out so you can get it back out again eh.

gl.

 

[xenodius]

Impressive pressure! I'm pretty sure it is the back plate causing the wobble. Wish I knew so I could order parts now...

I'd like to try that rope trick, but with the clutch plate off the clutch is disengaged, so turning the bearing turns the drive sprocket/wheel, not the piston... right? Sorry if I'm overthinking this before I try it... just yell at me if you like and I'll stop asking all these questions =) It's the nut that comes off right after the clutch pucks in this picture you posted:

I'm super excited to get this thing running properly and fully broken-in, I LOVE this bike! It's perfect for my area-- I can get around just as fast as with a car (speed limits and all), I get great mileage, I have fun, and I have the best parking. =) And it has lots of TLC in it.

 

[GearNut]

I stuck a steel rod (old fubar'd screwdriver) through the top and bottom runs of the drive chain, as close to the sprocket as I could, and braced it against the magneto case to prevent the transmission shaft from turning. Use a piece of scrap wood to protect the soft aluminum of the magneto case.
The nut should come loose with a standard 3/8 ratchet and a 19mm socket.

 

[xenodius]

Thank GN, I got the nut loose! But... now I can't unscrew the plate!

Full size

I locked it up by sticking a socket between the drive gear and case, and pried across 2 of the 3 prongs with a flathead screwdriver to get it off, which just bent. I could jerk on it with something sturdier, but I don't want to break them off. I took it down to the small motor shop a block up the street, and they didn't know how to get it off and couldn't get it to budge either. Can I ask for more input, guys? It doesn't look like reverse thread. Sorry for all the trouble... If it didn't catch and seize, I'd live with the noise and just run it until it dies an early death.


Thanks for any input =)

 

[GearNut]

The 3 studs that you pried against have nothing to do with removing or installing the clutch. They are guide pins for the clutch pressure plate, and nothing more. If you have bent or loosened one you will need to either straighten it out if bent, have it welded from the back side of the clutch if it was loosened or replace the clutch. Running the clutch with a bent guide pin can cause engaging and releasing problems. Running a clutch with a loose fitting guide pin can cause the same as well as causing further damage to the affected guide pin.

The kit should have come with a puller tool. One end of it fits the clutch. The other end of it fits the sprocket and crank shaft pinion gear.
http://thatsdax.com/ENGINE_KIT_PARTS_PAGE_4.html
Tool is shown in photo on this page at thatsdax, upper left corner.

The puller tool is needed due to the fact that the clutch is pressed onto the end of the tapered transmission shaft, not threaded onto it.

If you actually got the clutch to spin on the shaft then you have sheared the woodruff key that prevents the clutch from rotating on the shaft. Clutch removal is necessary to install a new woodruff key.

 

[xenodius]

My bad, I misunderstood the design. Glad all I bent is a screwdriver! I'll have to order that tool, didn't get anything like that in the kit. Thankyou again GN! Think I should have it from here =)

 

[KCvale]

Heck, I have like 15 of those puller tools and you can have one, heck you have 2 for whatever the shipping cost is as I pretty much started throwing them away after saving 15 never having to use one ever after 2 years and dozens of builds.

Drop me an E (not PM) with your address.
Better yet drop my web site, poke around and use the Contact form.

This is yet another difference between Skyhawk kits and the (barley) cheaper BGF and HT kits, Skyhawks come with all kinds of extra parts like gaskets, plug, plug cap, tank filter, and of course the sprocket and plug puller tools.

Those extras may not seem like much and wasted money, until you need one that is.
All these $150-200 kits could use improvements but in my book there is no such thing as too many spare parts with a couple of exceptions, the plug and sprocket puller tools ;-}

 

[xenodius]

I'll hold off the generous offer for a moment, KCVale; I didn't really take GN's advice about using an arbor press because I had no idea the clutch plate was a press fit, and that was stupid. I should just always listen to you guys! =) I just took a run and asked the shop down the street if they have a press. Well, they have a huge one (5t, I think) so I'm going to bribe them for some access later and see if I can coax it on tonight. If not, I'll take you up on that offer and see what's what. Thanks guys =) The support on this place is amazing, I hope I can pay it forward. I'll report back!

 

[GearNut]

Arbor press? I do not recall recommending using one. There is no need for such a large tool unless you completely disassemble the clutch down to the 52 teeny ball bearings. Even then you can get by without an arbor press.
The little tool that KC is offering will remove the clutch. Nothing special is needed to install the clutch.
Note, do plan on replacing the woodruff key if you got the clutch to turn on the shaft.
If you buy a key from a hardware store you will need to reshape it to fit the shaft and clutch as these engines do not use a commonly found size.

 

[xenodius]

Sorry, I guess it was killercanuck that reccomended an arbor press, but just for fitting the bearings and plate together-- as you said.

I have no idea what I'm doing. I guess I do need a tool!

 

[killercanuck]

Doh! That was for getting the clutch apart, not off the engine. My bad, should've clarified. Oh and *facepalm* for suggesting the rope trick... rag over a screwdriver in the gears works better Or if you're chain's still on, an allen key through the upper and lower chain locks it up good too.

 

[xenodius]

No, you were clear, I just remembered incorrectly =/ And I actually ended up just sticking a small socket between the corner of the sprocket and case, worked like a charm! The nut was still ridiculously tight, had to hit my wrench with a deadblow a few times to get it off.

I swear guys, after I do this once and see how it all goes together I won't be so daft =)

I misunderstood and thought the clutch plate was fixed entirely by press fit, and that pressing it on further would remove the wobble it has right now.

 

[GearNut]

It is held onto the end of the shaft by a taper. Both the end of the shaft and the clutch hub hole have matching tapers. This taper has a locking effect. The woodruff key prevents the hub from rotating under a shock load. The nut applies even pressure towards the taper locked assembly and prevents the pressure from backing off under use.
When you remove the hub with the special tool all you are doing is applying pressure squarely and evenly away from the taper locked parts and the assembly will come apart.
Sometimes the taper lock is so strong that the special puller tool cannot overcome the locking affect of the taper without the tool being ruined. If this seems to be the case, while the tool is still good and tight against the assembly you may need to moderately hit the end of the tool (like driving a nail into a board, not sideways!with a hammer to induce a shock wave into the assembly to get the taper lock to come loose.

 

[tooljunkie]

i ruined my puller trying to get the clutch off the shaft.
locked the threads tight.
pulled really hard,instead of using gentle persuasion with my small swinging press(tapometer)((ball pein hammer))
and the threads slipped,pulled,galled ,locked.
i had a spare puller and used less force with the puller threads GREASED.
a couple light taps while pulling on wrench and it started to move.
i didnt accomplish anything .

it seems like my clutch shaft is not in the housing correctly,drive sprocket is too close to housing and clutch is running too close to cover.
rattles like crazy,i can completly deaden noise by putting hand on the clutch housing side cover.

 

[GearNut]

tooljunkie, lemme just do a quick "checklist" of procedures when using the tool.
You may already know all of this.

1. Threads of tool (internal threads, center bolt threads and outside threads) are clean of any debris. The threads must also be free of any nicks or buggered up threads. The cheap tools are known for being poorly made so definitely check for this and repair if necessary. After cleaning grease or oil the threads.
2. Threads inside the clutch, gear, or sprocket, (whichever part is being removed) are clean and free of debris.
3. Remove center bolt from tool.
4. Carefully thread the tool into the part to be removed, taking extra caution to not cross thread it.
5. Tighten tool into part ensuring that it actually is going all the way into the part and not just catching the first few threads in the part and binding up.
6. Grease or oil the tip of the tool's center bolt and thread it all the way into the tool until it bottoms against the end of the shaft.
7. While holding the outer part of the tool steady with a wrench, tighten the center bolt very firmly with another wrench. The part should come free. Too tight and you risk stripping the threads on the outside of the tool and the inside of the part. If you think that things are getting too tight, but not yet "stripping the threads tight" you should hit the end of the center bolt, while everything is still tightened and under pulling tension. It may take a few hits. There is no reason to hit the center bolt VERY hard. A couple of moderate hits should do the trick. If it still does not come free then further manipulation with a torch is in order and things can get veeery tricky when using a torch around greased up, tempered parts. An alternative to using a torch is using freon, Co2, or "Freeze off" brand lubricant to actually freeze the parts causing them to shrink and breaking the taper locked bond.

One never actually "pulls" on the removal tool with their hands to separate the parts until after the taper locked bond comes free.