Motorcycle Repair: BIKE PROBLEM, importing electronics, dirt bikes

Question
Hi,

My name is NAGY and I am a fellow Expert in Home entertainment and satellite TV.
I will include my email address is case we are following up on the problem I have since I have pictures I would like you to have a look at:
nagygeorge@optusnet.com.au
I live in Melbourne AUSTRALIA and I've got an Engineering degree in Electronics.
I have been importing Electronics and computer peripherals for years from China but recently I have ventured in Dirt Bikes' Imports.
I have imported 125cc 4 stroke, 1cylinder, 2valve dirt bikes replicas of Honda from a manufacturer called Apollovehicle (www.apollovehicle.com)
To make a long story short, I have only sold ten  or 12 and I already have BIG problems with 2.
The second one I haven't checked on yet as it's an interstate customer but the first one I have already replaced to the customer and I am trying to see what could be wrong with it.
Customer bought on a Saturday, called be back Sunday saying he's got problems with it, I go and see him on Monday and the problem is:
Bike is very hard to start and when it does it only runs with chocke ON even after warming up the engine and is dripping oil heavily.
I tried a new carby and air filter with same problem.
I followed up the dripping and it came from under the engine cover, I took the engine cover off and it is dripping (or rather spraying if I can exagerate a bit) oil from all around the small sprocket.
Engine is not even 1 day old.
Could the customer have done something to the first engine run that caused that?
Let me add that for transport, the engine breather comes with a cable tie, when I went to see the bike the tie has been removed as per assembly instructions but if it hasn't been removed could it have caused that (I am thinking if customer didn't do it at first and is lying to me)?
Could the oil coming off around the sprocket and sprayed by means of the chain when it turns, affect the magneto and causing thebike to idle if not in choke?
As I said before I have some pictures if interested and sorry if I wrote a bit too much.

Any and all help appreciated (also any website addresses to read about engines, bikes and repair would be appreciated)

HAPPY EASTER

NAGY


Answer
Nagy.. you can send photo to me through my website:
www.vintagehonda.com

Chinese copies of Honda products can be somewhat of a risk, as they really are not built/engineered to the same standards of quality and design.

The failure to run w/o choke, is generally due to a blocked idle jet in the carb and/or mixture adjustment problem. I also recommend checking the valve clearances before running the engines and then again after a few hundred miles/kms.

If the engine breather tube is pinched off/blocked, the crankcase pressure has no where to go, so starts seeping oil along shaft seals or wherever the path of least resistance is.

Bear in mind that the drive chain should have grease or lubrication on it, that will melt when the engine is warm and running, having a tendency to fly off the chain and sometimes look like an oil leak.

If the bike has the usual CDI ignition, an oil leak really doesn't affect the ignition system. Could be an improperly installed oil seal, damaged/defective seal, but do check for proper crankcase breathing.

Bill Silver www.vintagehonda.com