South West Bikers | Motorcycle Forum

I don't admit to being an expert in filters, but...

Isn't there a spring valve inside each canister oil filter?

Maybe there were a few bad one's in the batch and you've got the good one fitted now

6 Bar is only around the 85psi mark. Generally a plain bearing crank engine will run at around 90psi at around 4000 to 5000rpm. It sounds like one of the pressure relief valves is stuck, these are tube with a ball bearing inside with a spring over them exerting pressure, screwed into an oilway, when oil pressure exceeds the predetermined spring strength the ball is pushed clear and oil bypasses back into the sump via a pair of relief holes in the tube. If a crankcase breather hose was blocked/crimped I would expect it to either burst or blow off before that kind of pressure is reached. Crankcase pressure will rise masively if the combustion pressure can blow past the rings, but that would not cause the oil pressure to increase to that extent.
It sounds like an oilway is blocked causing pressure to back up as oil is being pumped around the engine, normally this would cause the bypass valves to operate before engine damage occurs. Until the cause is identified I would not attempt to ride the bike. One question though, you say the bike fired up and then went Kaboom throwing oil everywhere. Where did the oil come out of the engine? did it blow the filter off? Or did it exit the motor via a jointing surface or oil seal?

It P!$$ed out from around the seal of the new filter... and I mean Gushed out... Like a hose pipe...

There have been a lot of updated oil filters from different manufacturers lately. Some have a different pressure relief valve operating point so it's worth making sure the garage has got the latest filters as some back street garages use up the old ones on new bikes but the oil flow rate is wrong and can cause a pressure build up. It's a bit of a far out possibility since it's usually the flow rate that's altered rather than relief pressure, but none the less still a possibility. I've also known one or two back street shops fill the sump with oil to the oil level mark, BUT with the bike on a sidestand which means about 2 litres too much oil to get to the mark!!!

I think that the filter has either not been fitted correctly, or there is a manufacturing fault in the filter which does not allow it to seat correctly, and as the pressure builds the seal fails. It may be that the shop has had a batch of dodgy filters and that is the cause. The oil is passed from the outside of the filter medium through the filter and returns into the engine via the centre spigot that the filter threads onto, so if there is a problem with the seating or sealing of the filter it will blow out from around the seal as the pressure is highest at that point where the oil is being forced through the filter medium. Get the shop to check the threads on the filter and the spigot on the motor, you may find that the filter will not spin on quite as far as it needs to and is becoming thread bound, it seals at lower pressures but once the oil gets to a higher working pressure the seal is failing.

Not exactly a 'Back Street' garage guys...

SP Motorcycles in Marsh Barton... I've been assured they used the latest 'genuine' suzuki recommended filters.

I must remember not to ride behind you at Pembrey

You want to borrow my Haynes manual nick?

Dave wrote:I must remember not to ride behind you at Pembrey

They've had it 2 weeks and still don't know what's wrong...

At this rate I won't be going to Pembrey...

I was down there yesterday and I spoke to Dave and Terry about it and after Terry explaned what he has done so far it is a very strange one.

I feel sorry for them as what was a simple service is now a nightmare to sort out.

Hope you get it back soon Nick

Any up-date on this mate ??

I would of put my money on the oil filter but being genuine filter seems a bit odd

Update...

I got a call from Terry (the mechanic on the case)

It was a bad broken phone signal but I got that he decided to change the Pressure switch and flush the system through...

He said it was extremely unusual for the switch to be knackered but changed it just in case, he thinks whatever was causing the blockage/build up of pressure might be dislodged or come out with the oil...

Seems to have done the trick...

I think there was crossed wires about the pressures quoted...

The problem was that at high revs there was 9 bar of pressure, which seems to have settled down, and the 6 bar quoted is normal.

Terry is gonna keep her for a couple of days and put 50-100 miles on her to make sure she runs ok now.

Glad to hear they sorted it mate

sounds like it could be sorted for you then,bet your a bit releived

deej wrote:sounds like it could be sorted for you then,bet your a bit releived

Well... to be honest I'm a little apprehensive...

If he had found a piece of seal or something causing the problem then fine, but what if it's just dislodged and is still floating around...

I would rather hear 'I found this' than 'It seems to have cleared itself'