So I've had my 748 up and running for about 3months and lets say it's testing my love. I love the way it rides and sounds, but not been faultless. My latest problem could be a serious one,and I need some advise. I was riding it on way home after doing about 60miles when i noticed a lack of power, shortly followed by the oil light flickering. I coasted into a car park and the oil light stayed on. I turned off the bike,checked the oil level which was ok. I started the engine and gave it a little rev but the engine didn't sound good,so I turned it off quickly and called the A-Team. I left the bike for a few days and did a oil change. The engine started up,oil light went out and engine sounded good again. I let it warm up for 10min and took it for a steady ride. All was good until i raised the revs to about 6k, then it all came back as before. So engine off again. Can anyone help out with advise and knowing how delicate the engines are. Is the engine going to need a strip down???
These engines aren't particularly fragile but what you're describing doesn't sound good. I would suggest that an engine tear down is required. It could be the dreaded oil gallery plug in the crankshaft or excessive bearing clearance or numerous other things. If you genuinely have low oil pressure then any running of the engine could irreparably damage things like the crank, rods, and valve train.
Doesn't sound great but oil pressure senders do fail and it could (optimist) coincidentally have done so at the same time as another less serious fault? so maybe worth checking the oil pressure properly to see if that is the problem. Difficult to tell with Ducatis but is it especially noisy? (engine rather than exhaust/clutch).
It feels to me from your symptoms that when the engine is getting hot, and by this I mean oil getting right up to temperature the pressure is dropping because the oil is a little thinner, so this indicates a pump failure, or that it's only just providing enough pressure with cold oil. Next steps have to find a way to test the oil pump output, but the damage could already be done. How cheap is an oil pressure switch? if cheap ish then swap it out anyway and see if it presents the same symptom although I would still be really wary of running it. Your only other option I think is to take a cylinder head cover off and see if there is evidence of it being dry after having run for a few mins, you should see everything coated, if there is already evidence of scoring your engine is goosed. PS... I'm not a pro mechanic, but that's my understanding and hope someone can come along and validate it.
About a fiver for a non Ducati (Vauxhall) part but that won't tell you much as it only shows low pressure when it's really low, you'd need to fit a gauge to see what the pressure actually is. Could be the pump is fine but it's got low pressure because the engine's worn out. One thing for sure though; if the pressure really is low enough to activate the low oil pressure light at 6000rpm then something is very wrong...
Grrrrrrr, I guess I should expect the worse and see how I go. I will get hold of a oil pressure tester, but I'm worried that running it up from cold to test it could excessively wear out anything on the top end as everything will be dry. This feels like it's going to be a deep hole.
Agreed, I personally wouldn't be running it at all because it could be that now-salvageable parts won't be for long! Look at it the other way, you could take the opportunity to get it rebuilt and perhaps even spend a little extra and balance the components and do a little head work and end up with a really nice strong 748 afterwards. I guess then it's a keeper!
What was the oil like when you drained it? Any sign of metal in the oil or on the drain plug and check the gauze filter for metal, this will give you a good indication on oil pressure and engine wear issue, if the indication is engine wear then unfortunately it's a case of starting a strip down and start to check tolerances to find the issue and what needs replacing. Start at the top as an oil pressure issue will generally starve the top end first and show wear on the cams and rockers.
Ok, so I've decided I cant afford to pay someone to fix my bike and have decided to tackle it myself. I've never worked on a bike engine and feel like I might be jumping in at the deep end. But armed with the work shop manual hopfuhope I'll swim. I've started taking off the fairings,fuel tank etc. Ordered a crank turning tool and a clutch holding tool. Going to remove the oil pump and inspection plates to look at the rockers and go from there. If anyone can give me any heads up on anything else would be good.
Mate in my honest opinion i wouldnt unless your a competant engine builder, take it out yourself by all means but get someone with a good reputation to build the engine will save a lot of hassle and money in the long run.
I know my way round a engine, but never stripped a bike engine or a Ducati. And i know all manufactures have there own little quirks. I'm hoping once i start taking things apart something will show up.
Stripping it down is easy, the only thing that will give you some bother is removing the primary gear off the end of the crankshaft. As for rebuilding, well it depends what it needs but there are a few processes that will require expert knowledge...
So I started the strip down and found the spark plugs were oiled up and also the air box seemed to have a fair bit of oil in it. So I guess that means there is excess crank case pressure???
You might want to see if the swingarm pivot bolt is free, and if not start with the penetrating oil now...
