Cam Inspection

[Daegan]

Got the stator out for inspection and this is what I have. Looks like the oil had all 677 original miles in it as you can see the dark particles flowing out. The points look pretty good too considering (original?). Everything on this bike says ridden little, not tooled, not abused. Like Todd said, probably adult purchased, used little and parked.

Kirrby, what do you think? Looks like I have a lot of play left on that tensioner. Can that be backed out if it has been tightened too much? Is that possible? If one were to disassemble the tensioner bolt/adjustments what is the proper factory setting for it when replacing? May not be relevant but just curious.

I tried to get a good up close on the teeth of the gears. What do you see Doc?

 

[kirrbby]

I've seen some dirty oil before, and yours is NOT. At least not as far as 40+ year old minibikes go.

Everything I see in there looks good, and I know your stator looks pristine.
The rubber gear with steel teeth is the oil pump drive gear. That's the one that will usually show wear. Yours looks good from what I can see.
Right now is the perfect time to pull the cam chain tensioner out and see how it works. You can't hurt anything too much without REALLY being careless. Take the plug out with washer. Loosen the jamb nut a few turns then loosen the locking stud a few turns. Then use a flat screwdriver to get up into the hole and back out the adjuster...plug. Take it right out. There will be a spring that comes out right behind it. Then the adjuster...rod, will come out if you help it. There is another spring inside of it. The 2 springs are different lengths, so pay attention to which where. That's all there is to it. Clean and replace, but mess around with it as you put it back. The rod will slide up and down with resistance from the spring the adjuster plug puts more or less tension on the chain. When the chain is (not too) tight, you lock it is place with the locking stud and snug the jamb nut to hold it there. The rod has a flat side for where the lock stud hits it.

Make sure to tighten/torque the flywheel nut well so it doesn't loosen up on you. Also make sure the drive chain isn't too loose.
The rubber cap on the tensioner rod is a good part to replace...as racerx says, 40 year old rubber...

 

[69ST]

Kirrbby's right, your motor looks really nice inside, in those pix. Whilst you're working toward keeping it healthy for the next 4 decades, learn how to clean the oil spinner; it's overdue by a few hundred miles and a few decades. Stay on top of that, keep clean oil in it and this beastie's got lots of good miles & years ahead.

 

[Daegan]

Thank you for all of that step by step. The manual is quite limited. An O ring popped off that I assume goes on the back of the stator in that similarly sized space that goes against the lower gear?

racerx can you elaborate on the oil spinner? How to and where?

 

[kirrbby]

Mmm... no o-ring there. Two to seal the screws that secure the stator plate to the engine. One goes on the tensioner locking stud, under the jamb nut. One on the neutral light switch, if you removed that. Think that's all from that neighborhood.

 

[69ST]

Thank you for all of that step by step. The manual is quite limited. An O ring popped off that I assume goes on the back of the stator in that similarly sized space that goes against the lower gear?

racerx can you elaborate on the oil spinner? How to and where?

It's the chamber located beneath the throwout bearing flange. Oil gets pumped into the clutch, centrifuged, then pressure fed through the crank. The dirt, grit and garbage you don't want circulating with the oil, scoring parts, gets trapped inside. The oil, being lighter, flows through sans most of the nasty stuff...until the spinner starts filling up. Keeping this serviced, on a timely basis, makes all the difference in engine life.

 

[Daegan]

It's the chamber located beneath the throwout bearing flange. Oil gets pumped into the clutch, centrifuged, then pressure fed through the crank. The dirt, grit and garbage you don't want circulating with the oil, scoring parts, gets trapped inside. The oil, being lighter, flows through sans most of the nasty stuff...until the spinner starts filling up. Keeping this serviced, on a timely basis, makes all the difference in engine life.

Ahh. Searched and found CJs thread on Step by Step Spinner cleaning. Answered a lot of novice questions. I will do this.



In the meantime i got that tensioner out and you were right Kirrbby, it makes a lot more sense now seeing how it functions and what/how much each turn does. It did seem pretty tight where it was and i am thinking that i did add some to that unnecessarily now that i can actuate it by hand and see the tension. The cap looks good but for $1.36 from CHP....ill order a new one.

Anything i should get for the spinner job from CHP (bar the unforseen)?

****found my missing O ring when i strained the oil (figured it dropped in there)