please help

[smiffy]

i am new to this site and hope that some one may be able to help me.
i have a 3v 110cc pit bike(prostar)and the back wheel locks up when you push it (out ov gear)i think that the gear box may have gone.
it also makes a nocking in 2,3 and 4 gear when you ride it but only at high revs.please help

 

[benox]

When you push it in NEUTRAL the back wheel locks up?
Strange, this happened to my mate but he found that his back brake stick was stuck.

If its making a nocking noise do you mean, its studdering?

 

[FULL-ON]

id say gear box could be had it only way to find out is open it up and have a look

 

[smiffy]

i have opened it up and all the gears look fine.
the back brake is not binding.
but the oil in the gear box is as thin as water.
can this do the problem i am having.and what is the best oil to use.
the engine is fully bored and tuned to the max and it as a 36 mm makuni carb fitted so it is going to get very hot.

 

[Divy]

if its in neutral an the back wheel wont spin freely i think it could be the back brake locking up for some reason
this may sound stupid but does the engine run?? cause if its seized up it will lock

 

[smiffy]

the bike runs like a old man on speed.its not the BRAKE all the brakes are free from the discs.i may just change the engine and use this for spares.but who do's a good engine and will ship to the U.K.

 

[FULL-ON]

but the oil in the gear box is as thin as water.

don't know if this will cause it but should definlty change it not shore what sort in a 110 but its 10W40 in a 125 hope this helps

 

[smiffy]

flushed the gear box out and changed the oil.found no damaged gears when the engine was in bits.but when i was putting the engine back in the bike found the chain roller was damaged and hanging of the bike and also damage to the engine side casing.replaced roller and side casing and the bike is not making a sound.BUT THANKS TO ALL FOR THE HELP.