Help?!

[Dead66]

This is my first bike.
Aluminum Onex 29ner from Walmart.
This Balanced PK80 66cc from Ozark Cruisers:http://ozarkcruisers.com/product/two-stroke-pk80-engine-kit/

Here are issues:

1: from beginning I have worried about clutch. It makes sort of a "bark" when first engaging. I know that is normal. But as I continue to pick up speed it continues to bark a little as if it may be slipping? Not sure that it is and this may be normal. BUT yesterday I rode and reached 35mph and the motor reaching highest rpm to date. When I got back the clutch would not disengage. I carried the bike into the work room and left it. After it cooled off the clutch was stuck in the DISENGAGED position. How did it go from not disengaging to disengaged just by cooling off? I took cover off sprocket and taped the bolt holding sprocket and clutch popped loose and seems to be working now. Is there some adjustment I need to make?

2: the motor has been slow to get up to full rpm. It would run very well at medium speed until I got to full throttle and would then "bog down" for lack of better description. If I eased off on throttle it would reach higher rpm and run better. This issue has reduced over time.
Yesterday it seemed to almost be gone completely and motor reached significantly higher rpm. BUT at the highest rpm the vibration is really bad. Motor is firmly attached but vibration in seat is actually painful, literally. Is this possibly caused by rough carb issues?
PS this is in an aluminum 29ner I would have thought top speed wood be closer to 40 on such large wheels, no? I weigh 170.

Any advice is appreciated!

 

[Chaz]

Regarding your clutch issue, check the bucking bar and ball bearing for rust. A bit of clean up and fresh grease wouldn't hurt. I found crud in mine but it was functioning ok.

 

[crassius]

go thru cable/clutch adjustment and you should find where the problem is

if you can grab motor & frame and not be able to pull or push motor at all, it is tight, but moving the mounts just 1/4 inch will sometimes reduce vibration

note that some ebay folks are still selling the old, unbalanced motors while claiming they are balanced

 

[Dead66]

So I have discovered there seems to be plenty of room to tighten the clutch plate. But the clutch arm is now hitting the drain cock on the carb. I am using a short, aluminum intake billet so I see two options here:

1: Go back to the stock, 'S" shaped intake that will place the carb higher and out of the way

2" Bend the clutch arm backwards and away from the carb so that the arm can move further towards the carb without hitting it.

BTW... I ASSUME the clutch plate should be as tight as I can get it while still allowing for a completely disengaged clutch plate when the lever is pulled, yes?

Thoughts?

On the mount.... The rear mount is solid and stock. The front down tube mount is problematic. The tube is too large for the stock mount so I had to add the u Bolt contraption. When I attempt to move the motor, it "feels" tight. But you can clearly hear squeaking coming from this connection point with indicates the u bolt is moving slightly. Should I remove U bolt and drill hole into down tube so as to mount with through bolt?

THANKS SO MUCH for the help!!

Rob

 

[Dead66]

Here are pics:

 

[crassius]

clutch arm shouldn't move that far from its rest position - at rest, it should be just about straight back - maybe the bottom cam surface is worn or flower nut is way too tight?

 

[Dead66]

It's almost a brand new motor. Only maybe a gallon through it at most. Don't know how to see if the cam surface is worn?

I did tighten the butterfly a lot. But Even with it this tight, I can still move the clutch arm over (of course I have to swing the carb out of the way) and the clutch releases. I assumed that I would want the butterfly as tight as possible as long as the clutch can still disengage, No?

Remember that yesterday after hard ride the clutch was stuck in the engaged position. Then after it cooled it was stuck in the DISengaged position. Then I removed the sprocket cover and tapped on the bucking bar an everything started working again. I can't understand how it went from being stuck Engaged to being stuck DISengaged just be cooling off?

 

[crassius]

not even close to right - steps to adjust cable and clutch are in over 100 threads here

flower nut is set to allow wheel to free spin when button is locked

 

[Dead66]

ok thank you

 

[crassius]

just had a though that might be good to add to cable/clutch adjustment steps

if flower nut has been badly miss adjusted, then first would be to loosen it until clutch arm has same amount of free play both in and out (cam surface is flat so with arm pointing back, it should contact the same either way)

 

[Dead66]

So I seem to have clutch issues all figured out. Still breaking the motor in. I am now running 6oz/gal non-synthetic oil per the supplier's (Ozark Cruisers) insistence.

Riding today... Ride going well. Finally really got warmed up and started to run as well as it ever has. Went down a long, slight hill and picked up good speed and rpm. At bottom of incline the motor started spitting and missing. it slowed down a good bit and then recovered some. I tried loosening the gas cap with no change. I got home ok but motor never began to run normal again. Checked plug (NKG) and found it to show dark oil on it but it did not look terribly fowled. But it definitely is not the really clean looking plug you get when a motor that has the appropriate oil mix. I can not see air getting in gas line and loosening the cap makes no difference so I am ASSUMING that it is not starving for gas?

Any ideas?

 

[crassius]

I like 4oz oil per gallon (32:1), so it might be fouled a bit. Many short runs can do that too when motor doesn't fully warm up to burn deposits out.

Never hurts to try a fresh plug.

 

[Dead66]

So you like 4oz for break in?

 

[crassius]

that is harder to say these days

some motors out there still seem to need 40 to 100 miles for break in, while the ones I was getting only took about a mile or so to get to good power and another 20 or 30 miles to get to full speed

on mine, I started using only a pint of 16:1 to get it going, then fill with 32:1 thereafter - some motors may still benefit from two tanks (1 gallon) of 16:1 before switching to 32:1

since your plug may be fouling, I'm guessing you have 40 or more miles on the motor - if not, then it might be that you are way too rich in fuel/air mixture