Oil Metering Device Service/Setup

[nsaints]

Hi,

after having lived with oil pooling in the bottom of the carb box for sometime, replacing carb gaskets/lapping carb thinking that was the issue multiple times I think I have narrowed the issue down to a badly setup oil metering device or a worn seal within the oil circuit.

there's too much oil being delivered to the carb, as the filter is sodden in oil. Oil is dripping from the filter into the air box

I've had a a good look via Google and I can't find any guide to setting up the oil metering device, or pump. Can someone explain how it should be setup, or link me to a site.

Also does a standard P200 gasket set include all the gaskets and o rings for a oil metering device rebuild

thanks in advance

[henri]

i seriously doubt your oil pump is at fault ,from what you describe . a full gasket kit will have the pump gasket an the clutch arm o-ring is same size as pump shaft . replace the gasket an see if it cures it , remembering to pre-mix 1st tank of fuel to lubricate engine whilst pump primes itself .
but oil dripping from filter makes me think its actually oil an fuel blown back up the carb . a worn or damaged sealing pad or worn rings leading to a over pressured crankcase are the usual causes . theres always some blow back an oiling of carb tray ,run engine without the filter an observe the carb top to see if this is excessive . H

[nsaints]

Thanks henri,

I've ordered the gaskets, but also the parts to replace the non return valve in the carb box. She does smoke very heavy on startup as well, more than normal
The crank webs were covered in a lot of oil looking down the inlet port, and rotating the engine
Possibility some oil is weeping past the non return valve when the engine is stationary

I'll fit the parts and report back

Edit: I've just read a thread on another forum about the metering devices o-rings. It's the lower o ring that seals the inlet and outlet port, and leakage past this o-ring is likely cause of white clouds of smoke upon startup, after the motor has been laid up for sometime. 
Anyhow all parts are ordered. 

[nsaints]

Both o-rings and non return valve replaced. Too early to tell if it's been a complete success
1st startup today after two days standing and there's definitely less white smoke

Fingers crossed.

if anyone is interested there's an in depth explanation on this link. The same may have been discussed within this forum, however I haven't found it.

modernvespa.com/forum/topic124633

Moderator, please delete if links to other forums are against site rules

[nsaints]

well this is an old post I'm updating

the solution was the carb box had a manufacturing defect, replaced this part from a pile of spares that contained a old Piaggio oil injection carb box and the problem vanished. this was a bout 3/4 years ago
as a refresher the problem was two stroke oil leaking dripping down the back of the engine. no amount of oil pump rebuilds would fix it

[alan34]

Hello there I had all the same trouble as you I stripped motor and it was just the same afterwards I found that I was filling oil tank right to the top and through gravety two stroke oil is passing through the carb when stood and into engine and smoking on start up especially when I left it a few days as far as I know this is normal so I drained the oil tank till the oil is just above the sight glass and found this helps also if you keep you speed to around 40 to 45 mph it helps stops the oil spitting up into air filter which in time fills up and drains from the mixture screw on side of carb.

[gpowell]

Interesting to know.

[nsaints]

Jun 26, 2024 11:13:59 GMT alan34 said:

Hello there I had all the same trouble as you I stripped motor and it was just the same afterwards I found that I was filling oil tank right to the top and through gravety two stroke oil is passing through the carb when stood and into engine and smoking on start up especially when I left it a few days as far as I know this is normal so I drained the oil tank till the oil is just above the sight glass and found this helps also if you keep you speed to around 40 to 45 mph it helps stops the oil spitting up into air filter which in time fills up and drains from the mixture screw on side of carb.

I read the carb box being the cause on a US Vespa forum, this is why I tried it as the option of last resort