Cracked engine mont on pit bike

[THUMPY125]

a few months ago i cracked my engine mount and got it welded up but then two weeks ago it cracked through the welds. just wondering whether it has something to do with incorrect rear suspension.

cheers. Callan.

 

[RD RACING]

this weld cracking around the engine mounting points is due manly from vibrations plus engine weight with the lack of extra mounts. what i have noticed on alot of the chinese dirt bikes is the weight of the engine and the lack of good mounting points, have a look at the distance from the head end to the first mount.

 

[cass38a]

I dont know what caused the original crack but welding up a crack is always only a temporary fix as it will always crack again. Best to look at fabricating a complete new mount than to weld up a crack (must be same material as original frame and best if TIG welded by a boilermaker). If you fabricate a new mount you could make it out of a thicker guage cro-mo (or alloy) to beef it up a bit

 

[Divy]

yeah i cracked my engine mount on my pp110 i just got some thick steal an made new ones an welded them over the old ones its like 6 times thicker

i noticed my 138 had a stronger engine mount then the 110 so hopefully the 138 wont farrk up

 

[RKhater32]

Vibration doesnt do shiot to the mounts. Look at where the foot pegs are bolted. You have a 150+ pound guy Jumping on the pegs which are held to the engine with 4 bolts and the engine is held to the frame by two bolts. A 1/4" thick piece of aluminum isnt going to hold 250+ pounds repeatedy. It will eventually break. And aluminum doesnt bent... It breaks. The rear motor mount bolt is just a pivot point when theres weight on the pegs and the placement of the top motor mount is at the almost worst possible spot for holding all that weight.
The is a company in the states called Category 5 motorsports and they have a bolt on cradle mount that will bolt up to almost any frame and cradle the motor and take the stress off of the top motormount. Many people have put one of those on their bikes with a broken case and never had any problems since.

 

[RKhater32]

yeah i cracked my engine mount on my pp110 i just got some thick steal an made new ones an welded them over the old ones its like 6 times thicker

i noticed my 138 had a stronger engine mount then the 110 so hopefully the 138 wont farrk up

Did you mean thick metal? as in aluminium?

And welding cast aluminium doesnt work good. The metal that cases aremade of is pot metal, theres all kinds of different metals in that alloy. You can get it welded for a little extra security but a cradle mount adapter or frame is the only way to fix it.

 

[Stunt101]

you need a cradle frame buy the sounds

 

[RKhater32]

or a cradle mount adapter from Category 5. Thats the easy choice.

 

[THUMPY125]

Thanx guys i think i might order one and see how it goes.

 

[RKhater32]

You wont be disappointed.

 

[cass38a]

Has anybody got a cradle mount on their ride? Post a few pics so I can see what it looks like installed (I have found pictures of the part but not the instalation) Thanks