Evening all, at last got the clutch housing off, the tool from Burton bike was the wrong one after a few conversations and getting nowhere I ordered one on eBay specified as 26 tpi as Julian said it should be and it screwed straight in, it was still bloody tight and as Mike suggested gave the bolt a heavyish tap with a hammer (sip of tea) tighten a bit more another tap another sip of tea tighten,tap, sip ..... BANG frightened the life out of me,but it's off so hopefully I can start progressing. I haven't been idle while waiting to get the clutch off I've been cleaning and polishing, some bits are starting to look really tidy, I've cleaned up the cylinder as best I can but it's still a bit grotty deep in the fins,so any opinions on sand basting and powder coating would be appreciated. Cheers Dave.
More help needed gentlemem, one crankcase has what looks like a crack at the edge of the bearing but doesn't show on the reverse side, should I get this welded before replacing the bearing or not. The next is down to my enthusiasm removing the clutch housing I've cracked the plate behind it (engine sprocket access I think) again I could get it welded or should I replace it , if available of course. I'm also having trouble removing the crankshaft from the other crankcase I'm tapping it out with a block of wood but it only goes about 5mms and then jams solid, in doing it with the crankshaft horizontal do you think the weight of the crank is stopping it coming out square, to knock it out vertical I'd need to make some kind of framework to hold it all safely, any input would be greatly appreciated. Dave.
1hi Dave
the best thing I would say is, can you post pictures.
are you sure the crankcase crack is a crack and not a casting flaw/line?
if you are talking about the round cover 6 small countersunk holes and centre oil seal, Ive seen them welded. they only keep the oil in, no great pressure on.
I would tend to get the crank out vertically, the weight should help removal, best a two person job , presumably all gearing/keys are out from other side of casing. normally a hide/coppermallet is sufficient. side of a bench normally ok
Have you removed the crank pinion from the timing side? If suspended vertically it should pretty much fall out
Chaz, yes it's the plate with 6 screws fixing it to the crankcase which are all stuck solid but I don't really see a need to remove it, some photos attatched, I did think at first it was just a casting blemish but on closer inspection in not so sure,
Wardy, attached photo of crankshaft, as you can see it's moved about 5 mms but it's not moving any further, I can tap it back easy enough but that's as far as it will go, I've tried a bit of heat but that didn't make any difference. Cheers both
Photoes
a decent recomended welder should be able to fix correctly, with a bit of care and heat to respect the casting age, cost of welding the sprocket cover , may be cheaper to find a spare on ebay cheapest is a tenner than the cost of welding.
Hi,
It looks like the inner part of the bush may have separated from the steel backing as there seems to be too large a gap between crank and bush. If the phosphor bronze part has seized on to the crank it may then have spun in the outer steel part. If the engine was run like this then there could be a ridge catching on the oil groove. Some two part bushes are pinned so if the two parts have separated then the pins could also be causing a problem.
Can you see on the inside of the case if part of the bush is moving with the crank? The 5mm of movement should be enough.
If this is the problem then perhaps the option may be to remove the bush along with the crank and deal with it on the bench.
Dave.
Chaz, I've got couple of mates that run a fabrication shop, mainly working in stainless,so I'll take it over and see what they can do.I've decided that the plate has to come off now,there's no point in going this far and leaving something that could come back to bite you later
Dave I'll have another bash over th weekend and see if I can see from the inside what's happening, I'm not sure how the bush/ bearing is set up and I don't want to make an expensive mistake. Thanks again to you both. Dave.
Hi,
If you get the case really warm the outer bush should tap out towards the crank. Use a good fitting piece of tube or a large socket and hit it square on.
Dave.
Cheers Dave.
depends if the cover has been glued on with or without a gasket. may help with a bit of heat to break the seal.
chances are that the bimetal bush will need replacing anyway, of possible get a similar one not the single metal (brass) type.
if you havnt got a heat source, sunday is coming so it can go in the oven after the roast.
Hey mate, I played loose head prop but your talking something to dangerous for me.😀
Hi, got the crank out, two gas torches and an old box spanner in the end, can't quite see why it was so tight there doesn't seem to be any sign of burrs or scratches, I presume the bronze bush on the shaft and the steel sleeve in the casting both come off, also looks like it had a new conrod at some time. Dave.
Hi Mitchell,
As suspected the two parts of the bush have parted. Both parts need to be removed. Hopefully there will not be too much damage to the crank journal. Is this a late engine as it looks like that rod has the steel cap? Is the other one the same?
The replacement bush needs to be one piece phosphor bronze or if a two part one it must be pinned to stop the inner part turning and doing as this one has or it may just turn enough to block off the oil holes with equally disastrous consequences.
Dave.
Looking more closely I see that the cases have a 68- number and separate alternator housing so some one has fitted later rods.
Hi dave, photo of the two conrods bit of a mixed bunch but they seem in pretty good condition, I'm hunting round for a bit of tube to knock out the outer part but not sure how I'm going to remove the section stuck on the end of the crank, maybe I could carefully file down one side until it's paper thin and then try pulling it off, any ideas gratefully accepted, cheers, Dave.
Hi,
The one on the left is definitely a later one or at least a later cap. If they have worked like this then they should be OK. It may be worth checking that the big end 'eye' is perfectly round. Any imbalance due to the steel cap being heavier than the aluminium one could be addressed by having the crank balanced.
To remove the bush from the crank you could try a bit of heat and a very thin chisel or screwdriver to move it outwards. A gear puller may do it if there is a bit of a gap. The idea of filing it very thin should work but be a bit time consuming.
Dave.
Got the bush off as you suggested prized it enough to get a puller behind it, started giving the crank cases a good clean and signs of what looks like a bit of a bottom end breakage has occurred at zoom time of other, see photo's. I have access to a head blaster and was considering going over both cases and the cylinder obviously avoiding all of the machines faces, any feelings about this.the crank seems ok to me and I'm wondering wether new shells would be acceptable or is a regrind and balance what I should be looking for? Dave
Hi,
It looks like a big end has gone. Probably a bolt or nut has gone but the damage does not look too bad but it could explain the odd rods and caps. It could be that the rod that has the later cap is the one that failed so it could be suspect. I think bead blasting the cases might be bit harsh but others may know more about this. The cylinders should be OK. Vapour blasting seems to do a good job and I have put degreased cases in the dishwasher with good effect.
The crank probably needs to be measured properly before deciding on shells only. I think all the measurements and tolerances are in the manual. Also, I never reuse big end nuts and/or bolts. It is not worth the risk to save a bit of money compared to the cost of a catastrophic failure.
Balancing is well worth the effort and cost.
Dave.
Hi
Although degreased the cases are still pretty grotty but I'll stick one in the wish dosher and see how it goes, I think your right again about the crank I'll send it off for professional assessment, I'm sure it was Chaz that recommend a place fairly local in an earlier thread,thanks Dave, Dave.
my last one was http://devizesvapourblasting.co.uk/ he did a customers DR400 and removed all the black paint as requested also did my A50 cases,head etc. I think around £120.
in the past Ive also used someone down London or the south area but cant find him now.
you might find someone elsewhere but check their work and that they understand what you want done. I had a customer who had his square 4 cases "shot blast" by a specialist at Yeovil or Weston Super Mare, the cases were scrap, bearing bores overs ize and covers could never be polished .
edit
https://www.tsrvapourblasting.co.uk/ is the other one I used, think it was for a thunderbolt, good job well packed but nowadays its nice to have someone local incase of problems,
Cheers chaz, as we speak I have one in the d/w just to see what happens, surprisingly the boss in the kitchen never batted an eyelid. 😁