Hello and welcome to the forum from North Yorkshire.

I have found I have to check the oil level exactly as advised on page 99 in the handbook. The oil does drain down below the sight glass after a while.

More discussions regarding oil level in the thread Engine oil discussion and more.

 

I have a speed 400 and after a run with the bike level on the ground the oil level is correct in the sight glass but every day if i check it without running the engine it drops slightly and so within 4 days the oil level is no longer in the sight glass until i start the bike again and it takes a couple of minutes to pump back to the correct level. The oil light always goes out straight away. Can anybody confirm this is correct and does this happen to all the bikes after standing for a short period.
Thanks for any advice.

Rocket,

Your experience is exactly as mine was with my Speed 400 Poco Rosso after doing a complete oil and filter change including the cleaning of the 2 sump screens. I ramble away on this strange phenomenon (I thought) in the General Discussions thread Engine Oil Level Discussion... and more. This thread goes on extensively on this topic with some interesting photos that I came across, on and no and etc. You may enjoy that thread excursion but the reason the level drops is this; The Speed 400 engine has 2 sumps, a dry sump and a wet sump. When the engine is running, any oil in that dry sump is pumped via a screen at the bottom of the sump to the wet sump where the transmission/clutch assembly is and the site glass window. When the bike is not running some oil will seep back slowly to the dry sump side via that screen by gravity and over time you will notice the level dropping in that site glass window. Simple as that. The oil is still in the engine, but some has seeped over to the dry side lowing the level in the wet sump where the site glass window is. Once you start the bike the oil that is in the dry sump is immediately sucked out and returned to the wet sump side. Where you see the oil level in the site window again. There's more boring detail in the thread but that's the reason. To check the oil level after the bike has been sitting for days, start the bike and run it for a while and check the site glass window again after it has sat for a minute or two to verify the level has returned to the site glass window.

After my assessment of this phenomenon, my conclusion is that if I see oil in the site window, it's OK to go for a ride. If I don't see oil, run the bike for a bit and recheck. That site glass window is basically a go/no-go indicator. If you see oil in the site glass... go for a fun ride on your Speed 400.

I hope this helps this odd characteristic of our Speed 400 engines. It drove me a bit crazy for a while until I found and scrutinized the photos of the open crank case, etc. posted in the original thread.

Moto Nonno

Old Rockers ride... and ramble on...
If you still can
You must

 

Thanks. Good advice