I had a breakdown today...

[CTripps]

I was on my way to work this morning, and when I stopped at an intersection for some traffic to go by I heard an odd noise. Sort of a cross between a click and a tink, not a clink, more a 'tlink' if you will. Only once. Nothing changed about the idle, I got to the next intersection just fine, and while waiting for traffic to clear the idle went from it's usual (slightly high) down to a low idle for 10-15 seconds, then faded out and died. The engine had been running happily (it loves cool mornings) for a good 15-20 minutes by this point, (mis)behaving as it does any other day.

So, I start pedaling, let go of the clutch lever, and nothing. There's resistance but not even the 'put-put-put' of the cylinder passing air. Ever the optimist, I gave it a shot on the way home and had the same result. Then I convinced a bus driver my tank was empty (*ahem*) and got over the hard part of getting home.

Right now I'm too tired, sore, and ill-tempered to look at it, I'd be more likely to break something before I fixed anything with the day I've been having. Any ideas on where I should start looking and what I might be looking for when I have time tomorrow or Sunday would be appreciated. It's the 'standard' 66cc China Girl, probably 1100-1300 kms (700-800 m) on it by the way.

Thanks guys

 

[retromike3]

Ok, lets look to see what might effect it first. 1: pull the spark plug and place it on the top of the motor and see if you have a spark or if it has sufficient spark. 2: check to see if the your getting gas to the system. I had problems with the my carb on my last bike and had to swap it for the earlier one from my first kit. Finally check for compression, borrow a compression gauge and see if you have got a leak somewhere.

I had a similar problem myself I found that I had a bad plug wire so I went down to the auto parts store and got a better one for eight bucks and cut the distributor cap side off screwed in the new one and its worked so far.

Gas-Compression-Spark= running engine, Simple

mike

 

[biknut]

Hope it's easy to fix. Tell us what it is after you find out.

 

[CTripps]

Well, after I do the basic checklist inspection I'll start taking covers off and poking things with something. I'll probably add few good "Hmms" and "What the fuh?'s" to the process as well. I'll have to throw some batteries for the camera on charge before I fall down for the day, or grab some when we're out tomorrow morning. If I'm lucky, it will be easily recognizable as a broken something.

 

[GearNut]

Since you are not even getting a "put-put" out of the engine indicating that the piston is still moving in the cylinder, I suspect that something has come apart inside the transmission. The low idle may have been caused by a loosened/ relocated part dragging on something else inside the transmission/ housing.
Take the cover off and have a look.

 

[Ibedayank]

piston meltdown...
pull the head

 

[rustycase]

I'll agree w GN, based on your description.
Pop off the drive sprocket cover, and the primary drive cover and have a look what goes on.
Hope it's a simple, inexpensive repair for you to get it back on the road.
...it's not nice to fool the busdrivers...
rc

 

[vincent713]

IMO if the engine doesn't got put put then it might be the clutch slipping issue, check that too as well.

 

[kolomootro]

i would suspect the clutch to be slipping

 

[CTripps]

Okay, slightly better today, so here goes.. slowly.

Thanks for the input everyone.

I pulled the plug and tried to roll the bike. No good, the back wheel just drags. Plug looks good though. Got the cover off the gearbox. Apart from some crusty crud in the bottom, doesn't look too bad. The flower nut seems loose. When I swing the clutch arm in, I can push the underlying plate down enough with my thumbs to almost be able to turn the flower nut. Pretty sure that's not right. With the beast on the stand, if I pull firmly on the wheel (plug is still out) I can make the engine turn once or twice, but it's very hard. The teeth on both gears look alright to me.

I'm thinking to take the flower nut off next, and see what lies behind it. I'll add another pic when I get that far. I have to keep coming in for a few minutes now and then to warm my hands up, it's a nice but cool one today.

 

[CTripps]

Took the plate off, and had a look. The flower nut seems to be showing some wear where the keeper was. One of the clutch pucks seems to have more wear than the others, it was a little loose under my finger. It popped out when I wiggled it, have rotated it 180 and it's firmly seated.

 

[vincent713]

That loose grip might cause clutch to slip, try tightening the flower nut more to get a better grip.

 

[Ibedayank]

as I said pull the head nothing wrong with your clutch
your gonna need a new piston/jug

 

[CTripps]

Did a quick search here for tips on adjusting the flower nut, and reassembled everything. There were a couple of identifiable shavings of clutch puck in the gritty crud in the bottom of the case. A few adjustments and it's good to go, started up and scared the crap out of some of the local skate rats. So, looks like I'm probably going to have to replace the set of pucks, not something I'm looking forward to but doesn't look that complicated (now).

So I'd say nothing wrong with the piston or jug (this time), looks mostly like uneven wear on the clutch pucks. you can see the wear on the back side of the clutch plate on one of the earlier photos. I'm thinking the odd noise was the sound of the loose puck shifting from one edge to the other of it's hole, or shifting and binding against the clutch plate when it was disengaged.

Of the replacements offered by the sponsors on the sidebars, can anyone recommend a better set? I know anything other than the factory set is better by default, but beyond that?

Thanks again for your ideas and help. I'm back up and running again (for now).

 

[Ibedayank]

ct good to hear
only stock clutch parts that I am aware of
every time i hear that TINK noise its either a chain snapping or ring breaking....

 

[CTripps]

I was thinking it might have been a ring, I was happy to find it wasn't.

 

[vincent713]

I had a good feeling it was a clutch issue, glad you got it up and running!

 

[rustycase]

...those clutch pucks look btr than mine, and mine works fine...
to me, your pressure plate looks wonky... in addition to the flower nut retainer screw hole you circled in the pic.
A couple of the 3 holes for the steel rods look elongated from wear, and I'd suspect there may be a lot of wear on the steel rods, themselves. How do they look???

and I don't know if it distortion from the photography, or ???, but that pressure plate looks egg shaped to me... and the wear pattern doesn't seem to be quite right.

Is it me? or might there be a problem with it???

If the pressure plate was hanging on the steel rods and not sliding properly, that could be the cause of your problem...

Best
rc

 

[CTripps]

The lighting made taking pics a little tricky. I'll have another look at it soon, and see if there's anything like you described. With the flower nut as loose as it was, it could well have been hanging on the rods. The back of the plate did seem to have a little more wear in some places than others, the depth of the 'dimples' in the plate isn't consistent. The notch for the flower nut retainer did seem slightly chewed where it was when I opened things up. After adjusting the plate and snugging it up it's a different notch aligned on the keeper, and looks better. The puck that I turned around was loose enough to pop out when I caught it with the edge of a thumbnail.

I haven't had a chance to take it for more than a quick trip up and down the lane yet, I'm hoping tomorrow will be nice enough to ride for a bit. I might be back to having some time to get a few things done (or started), so we'll see what happens.

 

[GearNut]

the depth of the 'dimples' in the plate isn't consistent.

I have a brand new, never ran, outer plate that has the same irregular depth dimple pattern. Chalk it up to the stellar quality control that these engines are known for.