Clutch New 48cc Engine, clutch noise

wrinkledoggi

New Member
Local time
5:01 PM
Joined
Dec 5, 2009
Messages
17
Hi guys - just ran my Huffy Cranbrook w48cc for the first time(s) yesterday and today, finally got the thing to idle properly after adding an O-ring inside the carb cap . . . worked like a dream! Now, I feel lots of chunking and hear chattering and whine from the clutch . . . . how do I adjust properly? Can someone give a clear step-by-step? Thanks . . . . . Mark
:confused:
 
o ring good idea, what size?

I was thinking the same thing. Mine runs great but I wondered if the lopey idle was from the muffler I used or the carb junction leaking. Hard to know without maybe trying a little hose on it to see.

If its the grubee type, you are supposed to adjust the clutch lever the best you can to relieve the clutch, and tie down the lever/use the locking pin on the lever if you have it. Now open the case on the right side (not the bottom of motor) There is a locking nut, and a star shaped finger nut. Loosen the locking nut, then adjust with the finger nut, and lock down. The clutch should let you pedal without dragging on the clutch, as long as the lever is pressed down, then let you "pop" the clutch to start the engine. Let it out slowly, don't dump it, and it will last longer, just like a car.

What size O ring did you use, or did you just try some till one fit in there? I really like the idea.
 
OK well the clutch engages and disengages as it should, and with the lever pinned the bike pedals freely as it should. My problem is that the whole bike shudders and shakes when the clutch is engaged, and makes lots of whining noise. Will this adjustment proceedure cure that? For the inside of the carb cap I used a 5/8" O-ring from Ace Hardware, it was just enough to raise the slider inside so that there would be the right amount of idle speed adjustment - fit perfectly and worked like a charm.
 
Yes. It sounds like your clutch is let out too "loose"/far. You are not getting full engagement. The instruction book with mine described this problem and said adjusting the clutch as described would solve the engagment problem.

oh... on the "carb cap" I know what you mean now but we weren't talking about the same thing before. You mean where the cable comes in and the cap is hand tightened. I used teflon plumbers tape and it worked perfectly for sealing it. If you want to adjust it, there are 2 methods. The physical cable adjustment at the lever, and moving the C-clip on the needle inside the carb to change the "length" of the cable by mm. If you remove the cap and pull up the valve (note the orientation that meets with the idle screw on the tapered notch at bottom), you will get loose a spring, a silver c-shape washer, and a tiny tiny little black c-clip "packman clip" as the inst. worded it. You can move this clip along the needle to different notches to regulate the length. Do not lose any of the pieces or the carb will be dysfunctional till it is reassembled correctly. (do it over paper towels by taking the carb off.

I thought you meant put the o-ring in the carb fitting where it goes on the inlet tube! hahaha.
 
The screw with spring on the carb is for idle speed adjustment. There is no mixture screw. (unless you got something way better with your kit! :)
 
by using the o-ring inside the carb cap, I didn't need to take all that stuff apart . . . . just the thickness of the o-ring was enough to raise the slider to an adjustable orientation, without all the hassle . . . . (I like easy over complicated)
 
wrinkledoggi - I'm not sure where to start.
Don't use the cable sheath adjuster to adjust your slide level for idle - a big no-no. Besides other considerations, this leaves no slack in the cable, so when you corner, your idle is likely to increase.
The idle speed screw is there for setting the idle speed.
The cable should have 2-3mm free play so that as you move the handlebars from side to side the cable doesn't tighten and open the throttle further than intended. (Can be great fun when doing a u-turn.)
Also, once the engine is running, you don't necessarily need to pedal before releasing the clutch - depends on bodyweight etc. If you can take off without pedalling, go for it.

moving the C-clip on the needle inside the carb to change the "length" of the cable by mm
The purpose of the 'C' clip is not to change the length of the cable by mm.
The purpose of the 'C' clip is to make the (low to mid-range RPM) mixture richer or leaner by varying the amount of fuel relative to the amount of air passing the slide. ie. Raising the needle by one notch adds more fuel to the mix for a given slide opening.

With the clutch shudder, it's possible that the problem is being caused by poor clutch adjustment, as suggested by happycheapskate, so check to see that it's engaging properly and that there is some free play in the clutch cable when the clutch is engaged.
I would also check under the RHS side-cover and ensure that everything is tight.
These things do vibrate quite a bit until the clutch is fully disengaged and you get up to speed. Riding too slowly, near walking speed, will labour the engine and cause some shuddering and chain snatch etc. They're a bit lumpy until they get rolling properly.

... Steve
 
confirming information

This is mainly for other readers of this thread who will have questions:

I looked at the instructions again to see if I had told you wrong. This is a very simplified carburetor. Very nice. It does have a mechanism for adjusting the mixture across the normal speed range. see below.

Your idea is fine, and basically simulates "cutting" the cable to a shorter length by the amount of the spacer/rubber ring. Good fix if it works and seals tight. But if you cannot adjust the cable length by the threaded fittings at either end of the cable (lever end or carb end barrel adjusters), it is pretty odd. But its possible that these things are made by the thousands (cables) and that one was just inside of or maybe out of tolerances.

I agree with AussieSteve in that you should be careful that when you let off the gas, it idles down all the way, and that moving the bars doesn't tug the cable any. Have a good ride today!

The instructions had pictures of the internal carb parts and it says exactly:

The Air/fuel mixture screw (idle) should be preset at 3.5 turns counter clockwise from the totally closed position. DO NOT back off screw more than 4.5 turns or vibration may loosen the screw and cause it to fall out. <happy cheapskate notes, spare included in kit> If this situation occurs, stop engine immediately and replace mixture screw. If a more rich gas mixture is required you can move the jet pin "pac man" clip <c clip> to the next lower position notch.

I just adjusted the idle screw to wear it idles smoothest and not too high. I accidentally moved the pacman thing, but I'm not sure how it changed it because that was on initial inspection and assembly. It seems rich in fuel, but isn't backfiring or blowing fuel out of the exhaust. I have only driven it about 20 miles if that much, so I will see later today how it will do with minor adjustments.


I didn't mess with the mixture screw at all, didn't need to
 
Last edited:
Back
Top