Stihl Ms660 56mm Project (Zeda Frankenstein) Now 54mm

Will'smotobikes19

Well-Known Member
Joined
Apr 9, 2018
Messages
1,653
Well if the alum rod is good quality and a good amount of red loctite milled flat should work good. The 54mm version seems easier to build an engine from?
 


Jag

Active Member
Joined
Oct 6, 2018
Messages
199
yea, thats sad, rob seems to think hes better than everyone, toxic attiude (small pepe sindrome).


also, i would use jb weld to fill the ports, those rods will just heat up like solder, when the engines warmed up.
(jb weld should hold up fine, 550F, just make sure its the OG, not the kwik, i learned my lesson lol)

and its a 56mm, you might need to mill it out so it clears the bottem end.


lets see it make some big power!
Brazing rod melts at higher temp
 

Jag

Active Member
Joined
Oct 6, 2018
Messages
199
Ms660 Piston pin: 12mm
China girl Piston pin : 10mm
Crank rod: 14mm
Gap between piston pin pin area, idk what it’s called it’s the section on the piston pin where the rod sits: ~14mm

Like mentioned in the other thread a bushing must be used unless I drill out the connecting rod. Or if I can find a needle bearing of the proper spec

What bushing would be recommended? or needle bearing?

Cheap china girl style bushing

How well do you think this bushing will do considering potential to seize, produce more friction/heat and holding up to load, as well how long it will last ?
^^^^^^
Edit: this bushing will not work due to it being split
 
Last edited:

FNTPuck

Well-Known Member
Joined
Jul 2, 2018
Messages
648
FWIW the new true 80cc chinagirl motors use a 12mm wrist pin now. Don't remember if the big end is the same size or not though.

Never seen one in person yet.
 

Jag

Active Member
Joined
Oct 6, 2018
Messages
199
FWIW the new true 80cc chinagirl motors use a 12mm wrist pin now. Don't remember if the big end is the same size or not though.

Never seen one in person yet.
I don’t even know where I would find a rod from one of them or what to even look for.
I did find brass/graphite bushings that are 10x14x12 mm that I can enlarge to 12mm and use on the connecting rod
Bushing
 

JerboaJohn

Well-Known Member
Joined
Jul 29, 2018
Messages
1,272
Bad idea to drill the rod to 16mm?
not recommended, bcs let's say you have 16mm bit. it's not a precision 16.000mm. it could be 16.005 or w/e. you could drill 15.9 then ream it to 16mm and be within .0005. bearings are pretty close tolerances and need that. you could get chatter and chew up the pin, then trash the cylinder when the piston jumps around, killing the rings, you look down at 33mph at a horrible screech and don't see the pedestrian crossing the road and you both go down and it'd be messy lol
 

Jag

Active Member
Joined
Oct 6, 2018
Messages
199
not recommended, bcs let's say you have 16mm bit. it's not a precision 16.000mm. it could be 16.005 or w/e. you could drill 15.9 then ream it to 16mm and be within .0005. bearings are pretty close tolerances and need that. you could get chatter and chew up the pin, then trash the cylinder when the piston jumps around, killing the rings, you look down at 33mph at a horrible screech and don't see the pedestrian crossing the road and you both go down and it'd be messy lol
What about doing the bushings? Cheaper, 5 pack more easy to adapt to a machine to enlarge
 

Jag

Active Member
Joined
Oct 6, 2018
Messages
199
When I get to reassembling the case halves should I:

Use paper gasket with yamabond?
Use paper gasket with permatex ultra black?
Use only yamabond?
Use only permatex ultra black?
 
Top