I lost my clutch pin in my 49cc china 2 stroke when my clutch lever plate broke. does any one know where i can find one or can i make one?
lost the clutch pin
- Thread starter cumminsbayou
- Start date
Cut the base of a 5/16" drill-bit to 1". There's also a 5/16" ball-bearing in there...makes sure you haven't lost that too.
For your future reference: it's called a bucking-bar.
For your future reference: it's called a bucking-bar.
And be sure to pack the hole in the sprocket with grease before you replace those parts. The grease lubricates and will keep those parts from falling out.
You might have to experiment with the length of that pin to get the clutch to work like it did with the original part. The length is critical. Also make sure the end that contacts the clutch actuator cam is very smooth. Any roughness will increase clutch lever pull.
Tom
Home depot sells long bars of aluminum for cheap. They have all diameters, for example at my home depot they range from 1mm to 1 inch. Just buy one that is the right thickness and cut it to the length you want. Then you also have extra for next time you lose it 
Aluminum is too soft for a bucking bar. Use 5/16" OD steel bar.
The bars can vary from a hair over an inch to about 1 3/16" or 28 mm
Better to start off long and grind to fit.
The bars can vary from a hair over an inch to about 1 3/16" or 28 mm
Better to start off long and grind to fit.
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I concur. Aluminum, even something like T6 won't work, at least for very long. There's too much pressure from the clutch spring against it.
Cold rolled mild steel will work but a drill bit is your best option. The problem is cutting a drill bit. That's some hard steel. You'll need a high speed cut-off wheel or grinder. A Dremel will do it but you might go through a couple of wheels.
Tom
did it last night, I have one of those quick-change cutting wheel things for my dremel, it took a while, and the drill bit got pretty hot after 10 second intervals of cutting, but took a half an hour and the cutting wheel still has lots of girth on it (the quick change ones are pretty big, and pretty solid) I think I need a longer one though haha... I used an 8mm. Anyone know how to get the ball bearing inside to come out? seems to be jammed (I think thats why my clutch isnt engaging right away). I have a spare one here but I cant figure out how to get the old one out.
FYI, my bucking bar after being cut was 1.021", and was just enough to get full clutch motion and not touch the cable guide, but is far from being parallel with the case
Also any recommendations on that stupid M4 screw in the cable retainer that allows the handle to pull the clutch arm? I can never get it in tight enough and it just slips off, causing stalling at lights/stop signs and difficult pedaling to start it again.
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Go to a bike shop, hardware store, etc and ask for cable knarps. They look like this: http://www.jensonusa.com/!Pxg3QQXe4...dium=organic&gclid=CID0qsulkrgCFeh_Qgodv28Amw
Much better grip than the stock method.
Much better grip than the stock method.
I had no idea they made those, I'll look into that for sure! I thought a bike shop would only have cable ends
On a side note, that brand new bucking bar I made... didnt help, my clutch arm is, again already, touching the cable guide... I need to get that bearing out so I can put a new one in.
Unless someone knows of a way to force the clutch guts more to the sprocket side. maybe tightening the flower nut with the clutch handle pulled all the way in doesnt allow the clutch arm to return completely? I've tried tightening the main clutch spring, and loosening, and felt no discernible difference in clutch handle pressure. as far as I know jamming a screwdriver into the retention ring and pushing the bike forward will tighten it (and as far as I can tell, it does, as it brings the retention ring into full view) through the cable guide hole
On a side note, that brand new bucking bar I made... didnt help, my clutch arm is, again already, touching the cable guide... I need to get that bearing out so I can put a new one in.
Unless someone knows of a way to force the clutch guts more to the sprocket side. maybe tightening the flower nut with the clutch handle pulled all the way in doesnt allow the clutch arm to return completely? I've tried tightening the main clutch spring, and loosening, and felt no discernible difference in clutch handle pressure. as far as I know jamming a screwdriver into the retention ring and pushing the bike forward will tighten it (and as far as I can tell, it does, as it brings the retention ring into full view) through the cable guide hole
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if that arm is going too far under the carb, then either it was put in the wrong place on the splines of the shaft, or it has chewed up the splines on the shaft, or the shaft was worn away the flat spot that is supposed to push the bucking bar
look in there and see what it is
look in there and see what it is
Having just gotten VERY intimate with the clutch shaft on my engine, I have a couple thoughts. First, pushing the bike forwards loosens the main clutch spring. Righty-tighty and all that. Go too far loosening it and you'll foul the spring retainer on the clutch side bearing, possibly pushing either one out, which brings me to...
2nd, the clutch shaft is only retained by the bearings. If the action of the arm pushing the bucking bar (and fighting the spring tension) is enough, or if the engine case around the bearing has failed/wallowed out, it is possible to push the entire assembly to the clutch side. That how it's removed without splitting the case anyway. You'd probably notice it though. The clutch hub wouldn't line up the the small gear, and your chain would probably grind the case on the sprocket side (depending on size of chain and severity of the offset), not to mention the entire clutch grinding the right-side cover. One thing to try is careful use of percussive maintenance and see if you can move the whole thing over to the sprocket side by taping/hitting/smacking the flower nut. A safer way would be to remove the nut and clutch cover, thread on the gear tool and hit that instead with it's small bolt installed but not touching the pin. Don't hit the end of the clutch pin, you'll peen it over and never get a nut on it again.
I just thought of this too. Remove the sprocket cover and see how far you can push/pull the shaft. Mine only makes a slight click when it hits either bearing and probably moves less than half a millimeter.
Nah, I found the problem. Tightened the flower nut way too tight, and wasnt allowing the bucking bar to extend out to full length. So note to newcomers, dont tighten the clutch flower nut while holding in the clutch handle, even finger tight like that is way... way way waaaayyyy too much
. I got really intimate with *A* clutch earlier today and saw how it worked, and instantly knew why mine wasnt working. And you're correct, running it forward was loosening, pusing it backward tightens.
Here is one of the best threads regarding proper clutch adjustment > http://motorbicycling.com/showthread.php?t=22726
In short, do not start messing with the flower nut until you have a firm understanding of the clutch and how it works.
Tom
In short, do not start messing with the flower nut until you have a firm understanding of the clutch and how it works.
Tom
thats actually the same way I did my flower nut that caused the issues. It's better to tighten it finger tight without holding in the handle, then tighten it a bit more (maybe 1 turn?) to achieve maximum arm swing. Every full turn of that flower nut reduces your arm travel fairly significantly. That guide only affects the arm travel, the flower nut is only good for very, very fine tuning of clutch pressure. To really adjust clutch pressure you want to adjust the main spring according to norm's post.
Isn't that ironic, you can't get the bearing out and I am sitting here with my newly built engine on the new bike doing nothing because the bearing must have fallen out when I sent the case to the machine shop to have the cylinder stud holes re-tapped. You can't get things out when you need them but they will fall out when you don't want them to. At least this thread let me know what the problem was and now I know I have to get another 5/16 bearing.
