I thought the same thing at first, but I have another CSR crankcase here and it has the same hole.
Interesting that yours has a small drain hole directly back to the tank.
Presumably a mod to improve oil drain by providing a bigger hole?
Engine dismantling questions
- clanger9
- Posts: 1163
- Joined: Sat Jun 20, 2015 9:38 am
- Location: Chester, UK
Re: Engine dismantling questions
1989 Moto Morini Dart 350
1993 Ducati 750SS
1993 Ducati 750SS
- Ozmadman
- Posts: 2651
- Joined: Wed Dec 14, 2011 1:02 am
- Location: ESSEX UK
Re: Engine dismantling questions
And dropping the oil onto the big-end which can only be a good thingclanger9 wrote:I thought the same thing at first, but I have another CSR crankcase here and it has the same hole.
Interesting that yours has a small drain hole directly back to the tank.
Presumably a mod to improve oil drain by providing a bigger hole?
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
- clanger9
- Posts: 1163
- Joined: Sat Jun 20, 2015 9:38 am
- Location: Chester, UK
Re: Engine dismantling questions
On a related note, does anyone know how oil gets to the drive side main bearings? There doesn't seem to be any specific oil supply.
I'm wondering because the inner main bearing on my engine is completely destroyed, though there is little else wrong with the rest of the engine (other than severe wear on the timing side bronze bush).
Here's a picture: The rollers were all there, but one fell out when I dismantled it. You can see the rollers are all shot and the inner track is rough, although oddly the outer track is undamaged. Anyone care to speculate on what could have caused this?
I'm wondering because the inner main bearing on my engine is completely destroyed, though there is little else wrong with the rest of the engine (other than severe wear on the timing side bronze bush).
Here's a picture: The rollers were all there, but one fell out when I dismantled it. You can see the rollers are all shot and the inner track is rough, although oddly the outer track is undamaged. Anyone care to speculate on what could have caused this?
You do not have the required permissions to view the files attached to this post.
1989 Moto Morini Dart 350
1993 Ducati 750SS
1993 Ducati 750SS
- Ozmadman
- Posts: 2651
- Joined: Wed Dec 14, 2011 1:02 am
- Location: ESSEX UK
Re: Engine dismantling questions
Just old? cheap bearing fitted? lack of oil in the past?( easily done if the P.O hadn't kept a close eye on the level) change both bearings and fit two of the roller type like your knackered one (early models had ball bearings) the recommendation for fitment of the inner bearing is to make sure the outer track stays secure in the casing by centre punching the casing is 3 positions once the other bearing, breather stator and inner track has been fitted (maybe these days some loctite will do the same thing)
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
1960 Model 8
1974 Yamaha RD250B US Model 6 speed