Orion TDR 125... guru help needed

[DynaMic]

Gday,another new member here.Excellent web site,(sorry if i'm posting in the wrong section,couldn't find a new member section).
I have a few dumb questions about my son's new bike.
1:Oil...how much and what weight?
2:Carby...its very small so what is the ideal size?i can get Mikuni 30mm for $50 or 28mm for $80 both new... bargain,or bollox?
3:Valve stem seals and oil ring blow-by(do they have oil ring and valve stem seals?)Bike is burning oil since first started,only been riden gently once.Will it all bed in after run in or is that just standard China Ducar quality?
any advice would be much appreciated
Cheers
Mic

 

[Cactus Jack]

Ha Ha ... Nobody wants to answer for fear of being called a Ramakrishna "GURU" ....

1 .The link below should answer your oil and run in questions ... The best way to set your oil level is to go off the mark on the dipstick ... too much is no good and so is too little ...

New Engine Break-in Procedure

2. The oval bore "30" Mikunis are in reality = to a 26 mm carb ... they are well known as 26 Mikunis in the US and have 26 stamped on a flat pad on the manifold mount flange ... the rear bore of the carb is 30 mm but the manifolds are only 25 to 26 mm so you end up with a big mismatch ... They work OK that way once properly sorted out tho' ... A round bore 28 mm carb will be too big unless your motor is ported and cammed ... A 26 round bore matches the stock manifolds best ...

3 . Yes they do have valve stem oil seals .... IF they're worn or improperly fitted the engine will puff white smoke out on start up due to oil running into the ports but then it will go away as the oil burns and diminishes ...

They have oil expander rings on lowest groove of the piston ... IF the oil rings are gone the engine will blow smoke on start up and it will get worse as the revs increase and on back off when oil gets sucked up into the combustion chamber by the cylinder vacuum ... Engines can also puff light white smoke if new rings are installed wrongly with all of the gaps aligned in the same position ... You want all the gaps to be staggered apart and away from the thrust side of the bore (bottom on a horizontal ... front of a vertical) ...

 

[liljohn_92]

i have this bike... a 25mm was too much fuel for mine...

and i f###ed my motor pretty quickly

 

[unitrider08]

i had same bike as that till i had a major crash luckily i came off after first flip but bike didnt work out too good but myn was a tuff lil engine after running in myn was like january 07 or like end ov 06 i had it till bout 3 months ago and it was pretty sweet but go by dipstick is what i done

 

[DynaMic]

Thanks for all ya help. I ripped off the carb yesdy and its a 20mm with 24mm manifold...so i ripped the carb off another old 125 its 24mm,this bike goes much harder so i'll try swappin them over once run in.
as for the burnin oil,if that doesn't disappear i'm leanin towards faulty valve stem seals as thats what signs its showing.I dumped the shipping oil and replaced it with Shell Advance 4T Mineral oil before i 1st started it.The oil level is about 2mm below the Full mark on the dipstick,so should be fine.Oh well,see what happens once its all bedded in.

Cheers
Mic