Oil light comes on when bike gets warm/hot

[colonial]

Hi folks

I was cruising across town this evening on a kat that has been sitting and run infrequently over the last ten years. The oil light came on after it got warm/hot and stayed on. As this is a low mileage machine, with excellent compression I was surprised, and immediately pulled into a garage.

Put her up on the double stand, and the oil window was showing full, so I started the bike and the level dropped as expected, which means there is circulation. Engine sounds fine, but I suspect the oil filter and the mesh screen need replacing/cleaning respectively.

I was wondering if any of you have come across this problem before. The oil light goes off and stays off when the bike is cold...

Needless to say I am going to whip it into my local bike blokes for a service check up.

Any tips on ensuring old oil is completely flushed from the system, or merely ensuring that your oil circulation is not being hindered by sludge/blockage would be much appreciated. Not having a decent spot to work on the bike is very frustrating.

thanks

Peter

[sparki]

Could be the oil pressure switch... Or like ya say the mesh could be gunked up... Pop the sump off and have a gander

[FBJ]

them pick up strainers are quite cheap

[colonial]

Thanks for the tips folks, I think I will drop at the bike shop. Also have an issue with the starter motor, it struggles to turn the motor over, I suspect it was not disengaging, and is now totalled.

[FBJ]

Starter clutches can be weak mate. U need to make sure ur nary is always charged.

[sparki]

.., and is now totalled.

as in it doesn't work at all?... presume it only struggled when it was hot yes?

[colonial]

It works well enough to crank the bike, but only just, the bike starts very easily, but it is not smooth running whether hot or cold. More of a chunk, chunk, chunk till it starts than the normal high pitched whine. Think the starter clutch needs checking too - forgot about that, thanks.

Will add it to the list of things to check at service.

Regards
Peter

[johnr]

as has been said, the roller crank gsx motor is from an age of low tech oils. modern synths are fantastic things but the kat motors oil light is powered by a switch that is literally a plunger that is pushed open by the oil passing it. the thinner the oil, the easier it is for the switch to chatter against its seat. also having well balanced carbs makes it less likely as the smooth tickover makes the oil pressure less likely to fluctuate.

[colonial]

Thanks John, I didn't know that, thin oil is a very likely culprit. This has been ridden/serviced sparingly over the last ten years, and the oil is dubious to say the least. I am test riding it, and refining it as I go.

Once I get the oil/starter sorted it will be off with the carbs, and off to allens performance with them for a complete refurb/overhaul. It pulls extremely well, but the idle is suspect, and I am sure they could do with a good clean out. I would do them myself, but I do not have a garage to work in, and I have done enough carbs to last me ten life times( and I am getting lazier with every passing day)...

[colonial]

Thanks for all the advice folks. I got it back from the folks at citybikes today. Some feedback: they said the sensor was bunged up, they cleaned it and put it back. Loose wire on the reg - bike wasn't charging. New oil, plugs, plug caps, and she runs like a new bike. I am stripping my other one for restoration, so this will have to wait its turn. I intend to restore it to original condition over time, I think the mileage and condition warrant it.