"Happy Time" wristpin bushings

srdavo

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Joined
Nov 4, 2006
Messages
3,162
But I'm not laughing.....1st, let me say this 48cc has been run (hard) since 2005. It still runs strong.
the funny sound....almost sounds normal for a 2 stroke. you know....the popping, ring-ring-ring ya get when you let off the gas. really loud. At 1st I thought it was an exhaust leak, so I put a new gasket on....no change.
ok...there is no unusual sounds while accellerating. Runs really well. but anytime I back off the throttle I get this loud metalic popping. It seems fine when the engine is under a load.

any ideas?
 
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thatsdax

Guest
It may be.....

It could be your wrist pin bushing has some play in it . Check and see.
 

srdavo

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Joined
Nov 4, 2006
Messages
3,162
yes, it was the wrist pin bushing!! Play wasn't the word for it. Slop?
 

srdavo

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Nov 4, 2006
Messages
3,162
this wrist pin thing is contagious. This 55cc bike has started making the same sounds as the 48 I just almost fixed. will be 2 years old in August. maybe 2000 miles.

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augidog said:
everything else is tip-top, but i'm afraid this bike's going nowhere...

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Kielohawk said:
Dax got one to me very quickly. I live in Ohio. Isn't he in Colorado?

I am really starting to believe that the wrist pin bushing IS the weakest link in the whole setup. I am going to start keeping an eye on mine especially after my first one went out with less than 300 Miles on it. I do believe that it happened while going down steep hills with the engine engaged and possibly red-lining. I pull the clutch on downhills now and idle it to the bottom. Good luck getting a bushing and taking your trip!!

Your bushing looks better than mine did!!
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Dan
 
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gone_fishin

Guest
i'll just mention that in my case, see above, there was still just a tad of brass left, so i never had pin-to-rod contact/wear/damage, i expect a smooth repair, any tips would be most welcome.

reality check: locally we've decided we need to treat the "happy time"s more like 20mph commuters and less like 30mph circle-trackers. we tore down quay-n-cruzin's just to be sure, all is well.
 

srdavo

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Joined
Nov 4, 2006
Messages
3,162
augidog said:
any tips would be most welcome.

reality check: locally we've decided we need to treat the "happy time"s more like 20mph commuters and less like 30mph circle-trackers.

sounds practical....prolly safer......but not as much fun. :LOL:

no tips from me....I did it the hard way.
I have my new bushing installed.....but in the process off punching it out of my spare connecting rod....and pressing it into place on my connecting rod, the darn thing "swelled" inward. yes the wrist pin fit fine...before I messed with it. I slowly honed the bushing to fit my wrist pin. it looks & fits good. time will tell if it holds up.

plus, I broke a ring re-assembing it. :LOL: :p Yup...the hard way!!!

I ordered rings & bushings from Dennis Foster this morning
 
M

MotorbikeMike

Guest
Tips

Hi put your wrist pin bushing in the freezer, and it will shrink a little then press it in, Mike
 

azbill

Active Member
Joined
Dec 15, 2006
Messages
3,697
Re: Tips

MotorbikeMike said:
Hi put your wrist pin bushing in the freezer, and it will shrink a little then press it in, Mike

that is a very good tip Mike
I am sure it will get lots of use around here
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thatsdax

Guest
I have them

Seems to be a weak point..With some. What was your mix ratio? Out of several thousand motors I have had around 15 or so with a premature worn bushing. When you replace the bushing, drill two more smaller oil holes off center and approximately 120 degrees apart. If you can. Keep mix around 20:1 . Thanks..Enjoy the ride.
 
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