My Girl packed it in

GoldenMotor.com

Dasmailca

New Member
Mar 20, 2013
32
0
0
Nova Scotia
:-||My first china girl finally worked excellent after much advice from the forum, and lots of tinkering, although it did vibrate a lot. After 600 miles though it seized up solid at about 20mph bringing me to an abrupt stop. I blamed this on an incorrect break in, in which I had made a mistake with fuel mixtures.
I had bought 2 more motors however, planning on 2 more builds, so I just swapped out for one of the new ones. I followed proper break in procedures.
The new motor worked excellent from the get go. I rode to work daily about 20 miles each way almost nonstop on a rural road at aprox. 20-25 mph.
After about 4& 1/2 weeks , over aprox. 2 days I noticed a significant loss of power to the point where it would not climb a small hill. I suspected a loss of compression. When I removed the head I discovered a not so small groove scored in the cylinder wall as well as small pits in the head. Even a small piece of metal embedded there. It seems that something in the bottom end has disintegrated. Is there any thing I can do ? Are there better quality parts to rebuild with ? Is there a better quality engine to start with ? Maybe 4 stroke would be a better choice ?
 

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Huffydavidson

STREETRACER/MANUFACTURER
Jan 29, 2012
1,076
4
38
st.louis,mo.
Pull the jug off and see if the ring are not broken. Then check the piston & wrist pin for play. Then check the connecting rod for playing as well up and down . If the bottom connecting rod bearing have play, its shot & done .
 
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MotorBicycleRacing

Well-Known Member
Jul 28, 2010
5,844
109
63
SoCal Baby!!!
www.facebook.com
When I removed the head I discovered a not so small groove scored in the cylinder wall as well as small pits in the head. Even a small piece of metal embedded there.

It seems that something in the bottom end has disintegrated. Is there any thing I can do ? Are there better quality parts to rebuild with ? Is there a better quality engine to start with ? Maybe 4 stroke would be a better choice ?
The damage is from your needle bearing coming apart.
Probably the upper one on the piston.

What motors and where have you been buying them?
 

Scott.D.Lang

Member
Jan 1, 2013
406
2
16
Chicago
not looking good. with the miles you are rideing at one time Id say if you dont mind a auto clutch go with a 4 stroke. That said though if you like 2 strokes like I do build you a balanced dax motor. The lack of vibs and power diffrence will make you smile big time.
 

Mike B

New Member
Mar 23, 2011
2,256
7
0
Central CA
Also looks like 3 of your head studs are snapped off at the head.

Yup, your motor is toast.

Bolt on the other one and hope for the best.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
What ever do mean Scott? The lack of power? That's nothing to smile about.
I think what he meant was.... the lack of vibs and increased power will make him smile..... this has been my experience with my dax balanced lower....... cant wait to get my hands on a couple more.
 
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mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
get a real motor go 4 stroke youl spend more time riding and less money fixing
Do them right amd the fixing is very seldom..... and besides you take all the fun out of it if you cant tinker with them a little........lol!

A good four strome is a darn reliable set up though..... you are right about that. All the good ones I've seen are custom builds.
 

Easy Rider

Santa Cruz Scooter Works
Jan 15, 2008
2,145
7
38
Nor*Cal
Wow! That's 4 1/2 weeks old?
I agree in Neil. It looks like your wrist pin Bering blew up and recommend using a better two cycle oil that doesn't leave so much build up.
 

Toadmund

New Member
Jan 19, 2012
792
6
0
Saint John, New Brunswick, Canada
My lower connecting rod bearing went and sent bearing needles up into the cylinder and piston ruining both.
This engine vibrated a lot at WOT, so much I could not see a thing in my rear view mirror..

My new motor (not a LEB or BFG) which is the cheapest I could find on ebay is smooth as silk at WOT, and my mirror shows a perfect image of all that stuff behind me.
 

stinky

New Member
May 21, 2011
84
0
0
The South
Dude watch my video s !!!

http://www.youtube.com/watch?v=uyj4kvf7xck

OIL YOU HEAD BOLTS then take off the head!!! The rust fell off of mine, but i think there was definetely some in there!!! Clean it out!! Don't do what I did and blow on it!! Dont move the motor at all. Hope that it is at top and going down. that way when you put oil and draw it down any rust you missed sticks to side.
Use a vaccumn!! I got some stuck in my ring, but got it clear after oiling it out.