Big oil pump worry on a Rapide, HELP PLEASE

[kerry]

Friend called here with a mystery problem and I could not help or understand so ask for your help.
Oil is returning into tank at a good normal rate but keeps rising and overflowing, what does this mean, he recently fitted a new paper type oil filter otherwise nothing else has changed. We drew off 1/2 pint but it still rises and over flows straight away ?
Kerry.

 

[LoneStar]

The oil should (nearly) all be in the tank normally - it could only overflow if there is too much oil. Most commonly this is due to the oil having migrated down to the sump while the bike was parked, then the tank being filled - on starting up, the extra oil in the sump is pumped back to the tank, causing overflow.

 

[kerry]

Thanks, appreciated but, we drained the sump and lowered the level in the tank and it still pumps up and overflows, he had to leave bike here while I ask for help ?

 

[Chris Launders]

Thanks, appreciated but, we drained the sump and lowered the level in the tank and it still pumps up and overflows, he had to leave bike here while I ask for help ?

How much did you drain from the tank, it should be down to the cross bar, though if you drained the sump I don't know where the extra oil is coming from.

 

[kerry]

It seems as though it is returning only ? oil level cold was below the normal position, he rode here 12 miles and it was overflowing, sucked out as I said 2 or three times, I was worried and made him leave the bike here, I guess I can check the sump and level again tomorrow but we have already done that !
thanks for advice, appreciated

 

[LoneStar]

The pump design has greater scavenge capacity than feed - so in normal operation, there will be very little oil in the sump, and the entire supply in the tank. The tank can overflow only if there is excess oil. With the sump drained, and the tank filled just to the cross bar, it's impossible for it to overflow - where would the additional oil come from?

 

[Sture Fredin]

Om man har en tvåstartspump kan man få problem när massor med luft skickas med tillbaka. Det är bäst med en originalpump.
If you have a two-start pump, you may have problems when lots of air is sent back. It is best with an original pump.

 

[timetraveller]

We leave miracles to the religious orders so it has to be obvious. If the sump was emptied and the UFM drained half way down then where is the oil to come from, even given some bizarre situation inside the engine. Primary chain case, gearbox, Nowhere else I can think of. If the oil had not been returning to the oil tank then I would have suspected a block somewhere but if the oil return is really normal then there are very few place left to act as a reservoir.

 

[bmetcalf]

Translated

If you have a two-start pump, you can have problems when a lot of air is sent back. It is best to use an original pump.

My addition: this might be the two start splashing that has been discussed here on the Forum. Has the owner had the bike for a while and this is a new problem?

 

[kerry]

All I can say is thank you to everyone, I will drain the sump and check the level and start all over again in the morning and report back,
the only thing he did was fit a new oil filter and 20/50 oil which he has never used before, just straight 40 grade.
Tomorrow is another day, watch this space.
Thanks all.
Kerry.