Hitchcocks Forum

Fully Synthetic oil ? I was Servicing My 350 AVL (Think Electa X)and Having acquired some Fully Synthetic oil I thought Why Not...?
Well I Did Fill it to Top Level But its Been Pissing it Out The Breather all Week (Plus Loads of Mayo)...New Duck Bill & a Bit of an Oil Swap (1Ltr in 1 out_) and it Seems Ok again,,,
Q: So Is "Fully Synthetic oil to Blame or was The Old Duck Bill & Full Level ? you think
Lastly Q: Could Fully Synic do any harm in an Old engine? (Well it did Flush out Heaps of Mayo)...Cheers all Craig

Craig you haven't said which viscosity you used. Sounds like it may be too thin when hot and with air cooled motor (think greater clearance) may just blow by the rings..

I would not of used fully sync in my iorn head classic but| i thought the more modern avl/electra would be ok.."blow by the rings??no smoke,no loss of power just a lot more spitting out the breather.... imho

I think you over-filled it. I can't see the oil making any difference.
Half way up the dipstick is plenty.

I was thinking more blowby of gas downward into the crankcase due to thinner layer of oil on the cylinder wall.

This would give rise to increased mayo ie the condensing of water vapour from the combustion gasses..

Something like 5W-30W may be fine for tight tolerance modern engines but just wondered if slack Alice indian engineering may require the assistance of a 50w oil to help with sealing..

After all it is only lubed by splash, not pumped under the piston crown to also aid cooling like a modern engine..

I may be talking through my arse but i believe your bike has already told you what it thinks of the stuff..

Part agree with you Both, I Normalcy Fill only Half way on Both Bikes AVL & Classic...And When it was Fully Syn,,They was NO Smoke But Plenty Mayo...Now Its an Oil Mix ..For Two days Running "All Seems Ok" Though the Oil is Still at the Top Mark... Conclusion? 1/2 Way Mark & Semi Next Time for a Happy Bunny...
Q: Just How Much Better is an Electra Oil Pump over a Classic/Std one?
Cheers All.

It is easy to overfill Electra engine. My strategy has been: measure what comes out and then fill with same amount plus say 0,1-0,2 litres.
There's nothing wrong using synthetic but it's wasting money as oil changes happen frequently.

Have never used fully synthetic, far to expensive for a Bullet engine, Bertie generally runs on 10/40 diesel semi synthetic, he loses minimal oil but just enough to keep the chain oiled.