Didn't realise it had a bypass, if I'd known I'd have changed the filter every 6 months instead of the yearly change. Ah you live and learn I suppose. When put back together its living in the lounge and will never see a speck of rain for the rest of its life! unless I get caught out.
There is a guy on Ducati up North called 853RS selling a 748 engine with damaged cases TB's and Oil cooler asking £250 or will haggle. If your cases are ok may be a cheap way of getting back on the road
I wouldn't be farting about rebuilding your blown up motor, there could be things wrong with other parts. I would either get Crankers complete motor or that one on ebay, bolt it in and your back up and running within a day.
Have sent a few messages out, cracking find with the ebay engine, keep checking it most days! An not too far away from me.
STarted reading this thread this morning and now im upto date i wish there was more to read still haha gonna have to wwait now for you to get thse parts good luck mate looks like its been an adventure and a half!
Quick update. Purchased an MG TF requiring a new head gasket,turned it round and made the funds required to get a bottom end for the 748. Have 2 or 3 people getting back to me, hopefully have something sorted by the end of the week. Neighbour has just bought himself a 1997 Land Rover Disco, have seen better vehicles in breakers yards but its keeping me in beer money and favours, especially for picking up a 748 bottom end!
Just read this from start to finish - Facinating stuff - Sorry to hear of your problems. Couple of questions though - Why would there have been excessive sludge build up? - Is this a servicing issue? You obviously know your stuff, so I'm guessing it could simply have been 'one of those things' Hope you get on ok with the rebuild...
Good luck with this. I had a similar problem a few years back in that I blew the gearbox up on my R1. Cost to strip & repair was ridiculous, so I kept my eye out for a complete engine/gearbox. It took 8 months for one to appear for the right money & location and it was just a mornings work to swap the units over. Hey Presto back on the road. I sold the old engine for bits on ebay and got back half of what the new engine cost. So all in all it worked out well, abliet I was off the road for 8 months.
I feel this is not really a service issue more of a poor design issue. the centrifugal force within the crank causes this sludge or ash to build up naturally, it really does just build up at the lowest point as the crank rotates, the centrifugal force then just compacting the same. there could be many argument for more filter changes and better quality oils but most of us do that anyway. IMHO this is possibly due to the filter not doing its job when the oil is cold, allowing the bypass valve to open thus letting unfiltered oil round the engine. a possible fix is to use a lighter weight oil or not allowing high rpm when the motor is cold, even changing the oil more regularly. I have noticed that the motors with the oil pressure relief on the pump suffer less with this but they do still suffer. So regular oil changes and a good quality oil possibly will keep it at bay, but this has got to be the regime from the start and i would recomend that anyone with a motor having high mileage should get this checked as well as the tightness of the crank bung that can back its way out, it is costly but may save you £££'s. There will be those that disagree but i use Mobil 1 0w-40 or AMS oil dominator range and have not as yet had any such problems with engines i am running, also some later model Ducati's have a different crank oiling arangement so do not suffer from this.
I have monies! (I checked, its a real word) Its always the way when you're saving for something, bills just seem to appear out of nowhere! Anyway, after so long scattered around my house, retrieving random bolts from kittens running amok I think the best thing to do would be to buy a whole engine as putting the thing back together might be a bit of a headache. Have a few options, a 748S engine which I assume would just be a plug in and go. I know they were tuned to a higher level than the base model 748E but the ecu should run it right? Another option at the moment is a 916 engine, I have 2 issues with this one, the first is that it was taken out of the bike and has been stood for 10 years and comes with no throttle bodies or loom, both of which I have for the 748 but don't know if they'll fit. Also don't know if the 748 ecu will run it. Finally there is a 996 engine but that has come out of an st4s and don't know if they are compatible. Anyone able to shed some light on these options?
Didn't the 748 'E' engine have the dropped exhaust cam heads as per ST4/Monster S4? Not certain if that makes any odds regarding performance or fitting though...
I agree with most of the above answers, i dont think you need to worry about getting the t/b's opened out, it is only mm, and if you leave them alone there will be more cance the fueling will be better as the 916 t/b will be suited to a 916 ecu, change both or none is my advice. i think the 916 way is a better option if you do much two up work but the 748 motor even in its std strangled form takes some beating for all round fun! To throw a spanner in, why not look for a 996 motor and go for it, throttle bodies ecu and all.
