Hello, I've got a spare engine for my 748 bip,I've used some of the parts( rockers, 2 cams ) to keep my bike on the road, I'm going to strip the engine down and re - new any parts that need it and replace the parts I've used and basically end up with a fully sorted standard engine.That was the plan, I've just noticed that one of engine mounts is cracked! Are these crankcases useless or can this sort of crack be repaired? Any idea of cost for the repair, thanks in advance Paul
This is a very common occurrence and happens when a bike is crashed heavily on the offside. Use a jubilee clip to wrap around the casing, that works, do not try and have it welded the cases might not take it and the metal is rubbish.
Better than a jubilee clip would be a very tight fit peace of tube, heated up to expand then slide into place it will then tighten when cooled down and look neater . Steve
+1, a machined sleeve (compression fitting) would look much better. Easy for someone to make too with access to a lath.
Another good idea,might try that one first.While I'm on the subject of what's useable in this engine, have a look at the barrels , they appear to have corroded through in a few places(I've circled where).........scrap ?
I think they're all like that and the gasket covers it anyway, they'll be fine. As for the cracked mount, depending on how 'crumbly' it is, maybe an idea to cut it off and machine a bush into the case to replace it?
The actual metal around the engine mount seems fine so I'm going to give the shrink fit collar a go,as for the corrosion,the barrels that are on my bike at the moment are not corroded through like these but as you say , the head gasket covers them I assume the coolant circulates through here
If you try and use a collar and shrink it on try and close the spilt up as much as you can. When you get a situation where the cases crack in this position you will find that it tends to taper the end of the mounting, I have seen a few really bad ones where it would take a lot of filing etc. to get a collar to fit snugly. Whatever you fit the good point is that it's very hard to see that the case has been "repaired" as the frame shrouds a lot of the edge of the engine mounting.
