1990 Yamaha SH50 Carburetor oil port

[mikee]

Hello,
I have this TK carburetor (TeiKei OA 18) on a 1990 Yamaha SH-50 motorcycle (scooter). Took this carb apart for cleaning but I have some questionning regarding the oil injection port.

The ''oil inlet'' located on the carburetor which inlet I can't find on any diagram on the web or service manuals, seem's to be a 'ball spring-loaded'' check valve.  The spring is missing.

Enclosed are pictures of the carburetor with the oil inlet ant the ball I presume was located inside. Could anyone confirm this is a check valve and that there should be a spring pressuring the ball to seal off the oil when the oil pump is off. Any comment/confirmation will be appreciated. Thanks

[geoffh]

Hi,and welcome to the forum,your right that info is hard to glean,maybe a previous owner fitted a non standard carb at some time,the spring must have been removed deliberatley ,does the scoot run if so does it consume the oil on offer.

Geoff

[aeroxbud]

Welcome to the forum.
I'm not familiar with your carb. But how you check the valve is working, is to blow into the nipple. If it's working, it will normally be impossible to open the internal valve. As a person cant blow hard enough to pressure it.