SHcooter.com

I read through an earlier post on burning oil, but wanted to get some thoughts on my SH’s situation.
I am not very mechanically minded.
Thanks

Now at 20,000 miles and for about the last 3,000 (possibly longer) it appears to be burning oil.
I check it every 300 miles and it is taking 150ml every time now.
Parked in the same spot on clean concrete I can see there is no leak.
No smoke seen.
No change in fuel economy, 110-120mpg when not mountain riding.
No discernible change in performance, down low or top end.
Temperature gauge unchanged, bang in the middle under normal conditions (where it has been from new).
It has been worked hard with long trips two-up, ~370lbs.
Quite a bit of mountain riding two-up, including plenty of 5-8% climbs.
Cam shaft replaced at 8,000 miles, don’t know the cause.
Regularly serviced, but not by me, including oil change every 2,000 miles.
Performed perfectly on a 500 mile ride in one day less than 2,000 miles ago, around 45mph most of the time.

It is the 2009 150i model purchased new in 2015.
(Viet Nam continued making the older model longer than in the West)

I live in a developing country where the approach of even good mechanics for a scooter is to wait until something doesn’t work before investigating.

Welcome to Forum jharr.
Wonder what type/brand of oil you are using?
Other than that I haven't any other idea's .....yet.

Using the Green Wing dealer selected oil:
Honda
Pro Tech Gold
4AT
JASO MB 10W-30
Semi-synthetic

This may be simplistic but it wouldn't hurt to 'try' just changing oil brands. Not that Honda doesn't know what it is doing BUT for good reason full synthetic seems to be the way to go today.

If there are no external leaks and no smoke in the exhaust it seems strange because the oil has to go somewhere. Did you check your airbox where the air filter is?

Air cleaner replaced about 800 miles ago, nothing out of the ordinary.

I checked the manual and the oil the Green Wing dealer is using and I’m topping up with is appropriate. The bottles are 0.8L and have a aluminium tear away seal to stop tampering.

Still, who knows how long that oil sat in some warehouse or on the shelf? All organics deteriorate over Time and BTW, you never mentioned which 'developing' country you reside in......
At one Time I used to buy oil by the case and by the Time I get to the end of the case I could literally SEE a difference in the oil and can only imagine what a lab analysis would have told me.
With no other indications or reason for 'loss' a 15 minute oil change/substitution would at least 'tell' you something IMHO.........

In Thailand, so pretty good oil products.
Oil from different Honda dealers when on a recent long trip.
The oil itself seems unlikely.

New piston, valve, belt and drive face at 21,500miles

I took it to a mechanic who does a lot of scooter rebuilds.
The drive face and belt were worn too.
He put a full synthetic oil in it and advised to keep it under 50mph for 300 miles.
He also advised that the fuel pump and injector should probably be replaced in 3,000 miles.
Being Thailand it was $200 for everything.
It has been ridden hard two-up near the recommended max weight and sometimes on mountain roads, so I'm not that surprised it needed it.
Happy with the performance.
Photo of old parts attached.

Thanks for taking the Time to share your experience. It is of value here.
God bless the honest hard-working mechanics of the world, who keep us on the road.
Considering how she was rode, this is more so proof of integrity of design rather than fault.
Wishing you many trouble-free miles on your wise investment.