Crankcase repair...
- Thread starter Nick
- Start date
I guess there'll be several answers besides tig and not any old welder.
A couple of Laverda guys spring to mind. Piet in Germany and Laverda Scozia in Scotland.
If its a non matching numbers bike, you may find a set of crankcases cost the same or less.
Donor parts are ideal from scrap cases to repair, if you can find them. Looks like there is metal removed from around the seal/bearing housing but i cant see how much.
Ive posted a pic showing a case with a slice already missing from around the seal housing, if its through or almost to the bearing, it requires a great deal of care to prevent distortion of the bearing housing.
In your favour, the outer land is not holding the oil back as per pic of lower half, upper section looks mullered.
Find someone who's done it before to save yourself headaches down the road.
Rob
A couple of Laverda guys spring to mind. Piet in Germany and Laverda Scozia in Scotland.
If its a non matching numbers bike, you may find a set of crankcases cost the same or less.
Donor parts are ideal from scrap cases to repair, if you can find them. Looks like there is metal removed from around the seal/bearing housing but i cant see how much.
Ive posted a pic showing a case with a slice already missing from around the seal housing, if its through or almost to the bearing, it requires a great deal of care to prevent distortion of the bearing housing.
In your favour, the outer land is not holding the oil back as per pic of lower half, upper section looks mullered.
Find someone who's done it before to save yourself headaches down the road.
Rob
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The Sock
Hero member
- Location
- London, England
If nothing is broken through to the interior of the crankcase and you have the missing piece, you could glue or staple the top part back in. The main function of the missing bit is to keep anything from dropping in there but, as the 750 SFC demonstrates, it’s not critical.
pf1
Hero member
- Location
- Portsmouth UK
I have some cases doing nothing if you need them but laser welding is available near Portsmouth.
TeddyG
Hero member
- Location
- Portland Oregon
Was it a snapped chain or loose sprocket? You’re lucky you didn’t get hurt. It looks different than my twin, so it’s a triple? Hopefully you have the broken part and laser welding can fix it, depending on the extent of the damage.
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Yes broken chain. I'm trying to work out 'why' but most probably I did something stupid.
The missing pieces are somewhere on the M4 near Newbury...
At first sight I think the cases aren't breached so the ideal would be a set of busted cases that I could use to cut up and weld in the missing piece - if anyone knows of a busted set it'll save a good set being butchered.
Lucky it was a lightweight non o ring chain & only doing 60 mph...just think if it was an original 630 boat anchor!
Nick :-[
The missing pieces are somewhere on the M4 near Newbury...
At first sight I think the cases aren't breached so the ideal would be a set of busted cases that I could use to cut up and weld in the missing piece - if anyone knows of a busted set it'll save a good set being butchered.
Lucky it was a lightweight non o ring chain & only doing 60 mph...just think if it was an original 630 boat anchor!
Nick :-[
andre g
Hero member
as far as there is no oil leaking there, you don‘t need to to anything. The missing upper part of the case is just a cover.
OneThinBloke
Hero member
- Location
- Oxfordshire, UK
Hi Nick,
I have a pair of cases with a large hole at the front, snapped conrod...
I can cut out section you will need to repair yours if you wish...
J
I have a pair of cases with a large hole at the front, snapped conrod...
I can cut out section you will need to repair yours if you wish...
J
chrisk
Hero member
- Location
- Brisbane, Australia
My DT400 came with a bent top cylinder fin, I heated it up and tried to bend it straight. It busted off a section about the size of a plastic cigarette lighter.
I used some wood to act as a pedestal and used JB Weld to stick the busted bit back on.
I left it for a few days, file and sanded the excess, a spray of black paint (you could skip the black paint bit, if you want Nick
)…. six years later it’s still in situ.
I used some wood to act as a pedestal and used JB Weld to stick the busted bit back on.
I left it for a few days, file and sanded the excess, a spray of black paint (you could skip the black paint bit, if you want Nick
)…. six years later it’s still in situ.
pf1
Hero member
- Location
- Portsmouth UK
I have some cases you can have for nothing if you get stuck.
I guess youve figured it out now, the size it not an issue. Several folks run 520 chains, let alone 530 and they work well but the spec is important.
I would always refer to the manufacturers website to see what im buying. If it has classic in the wording, ill avoid as a euphemism for low quality or low spec.
Be aware the 1200 cases have larger holes to accept bigger liners and of course series 1 and series 2 vastly different ( if you do change)
Hi all,
Thanks for all the replies and offers of help.
'Onethinbloke' lives just 5 miles away so I'm going to look at his cases. It would be great if I can re-purpose his busted cases rather than butcher a serviceable set...but don't stand down just yet pf1!
My engine is a series 2 Jota but I think the area I want to cut and shut is common to all triples (top case area above mainshaft extending to the starter - I'm guessing if the donor cases are sandcast then the alloy would be different but other than that it should be okay?
The chain was a Iwis non o ring and I've talked with Jason. I've used these chains for many years and they stand up well despite being light. Jason thinks it may have been a stone between the sprocket and chain but in truth I think I messed up (age doesn't come alone). Sometimes you just have to hold your hand up, learn the lesson and focus on fixing what you broke.
Nick
Thanks for all the replies and offers of help.
'Onethinbloke' lives just 5 miles away so I'm going to look at his cases. It would be great if I can re-purpose his busted cases rather than butcher a serviceable set...but don't stand down just yet pf1!
My engine is a series 2 Jota but I think the area I want to cut and shut is common to all triples (top case area above mainshaft extending to the starter - I'm guessing if the donor cases are sandcast then the alloy would be different but other than that it should be okay?
The chain was a Iwis non o ring and I've talked with Jason. I've used these chains for many years and they stand up well despite being light. Jason thinks it may have been a stone between the sprocket and chain but in truth I think I messed up (age doesn't come alone). Sometimes you just have to hold your hand up, learn the lesson and focus on fixing what you broke.
Nick
engine cases weld very well, never had an issue as long as they are clean, no contamination in the metal
not the same area that you are looking at welding but came across this Series 2 engine that had the rear right upper engine mount welded up numerous times by persons unknown who had no knowledge of how to weld alloy, total mess and just waiting to break again
only option was to replace that section of the engine, lucky for myself I have a couple of engine cases that are way past repair and the donor engine in this case was a Series 2 engine, #7605 that the owner had near redline, broke the drive chain which sent revs sky high and threw the middle conrod which did its best to cut the engine in half
cases have holes in the top, front, bottom and rear, way past repair
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IMG_1457
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IMG_1471
not the same area that you are looking at welding but came across this Series 2 engine that had the rear right upper engine mount welded up numerous times by persons unknown who had no knowledge of how to weld alloy, total mess and just waiting to break again
only option was to replace that section of the engine, lucky for myself I have a couple of engine cases that are way past repair and the donor engine in this case was a Series 2 engine, #7605 that the owner had near redline, broke the drive chain which sent revs sky high and threw the middle conrod which did its best to cut the engine in half
cases have holes in the top, front, bottom and rear, way past repair
IMG_1455IMG_1457IMG_1460IMG_1471
piranha-bro2
Hero member
- Location
- Melbourne
That is beautiful work, Red.
Dellortoman
Hero member
- Location
- Tasmania, Australia
My bike came with a dodgy repair in the same area. It's evident that a chain broke at some time in the bike's history. Probably way back when rear drive chains were little better than industrial chain and used to break with alarming regularity. It's a much less likely event these days with mega strong O-ring chains and rivetted joining links.
It was patched with car body-filler bog and painted over with aluminium coloured paint. I didn't notice it when I bought the bike because there was enough dirt and grime around that area to disguise the repair. It only came to light a few months later when a lump of bog fell out.
It's a non-critical area that didn't involve the rear engine mount or any oil-containing area, so rather than strip the engine down to bare crankcase to get a lovely welded repair like Red's work above, I just did a better job of patching it. I cleaned out the remnants of old bog and did a much stronger fibre reinforced epoxy patch, with epoxy bog on the outside to re-create the smooth curve of the case. I painted it with an epoxy type aluminium coloured paint so it won't wash off when petrol spills on it. It's still holding together decades later and is pretty much undetectable by a casual observer.
I think of it as a temporary patch while it's waiting for a welded repair, perhaps if/when the engine needs to come apart for some other reason. But I doubt that'll happen during my custody of the bike.
It was patched with car body-filler bog and painted over with aluminium coloured paint. I didn't notice it when I bought the bike because there was enough dirt and grime around that area to disguise the repair. It only came to light a few months later when a lump of bog fell out.
It's a non-critical area that didn't involve the rear engine mount or any oil-containing area, so rather than strip the engine down to bare crankcase to get a lovely welded repair like Red's work above, I just did a better job of patching it. I cleaned out the remnants of old bog and did a much stronger fibre reinforced epoxy patch, with epoxy bog on the outside to re-create the smooth curve of the case. I painted it with an epoxy type aluminium coloured paint so it won't wash off when petrol spills on it. It's still holding together decades later and is pretty much undetectable by a casual observer.
I think of it as a temporary patch while it's waiting for a welded repair, perhaps if/when the engine needs to come apart for some other reason. But I doubt that'll happen during my custody of the bike.
Rob
Hero member
- Location
- Midlands, UK
I did wonder if that was the chain used. Bought one (M106SL) from Andy the chainman many years ago after he extolled its virtues. Decided against using it due to its very lightweight construction. Personal choice... o ring chains better suited to my riding.
chrisk
Hero member
- Location
- Brisbane, Australia
He's active on Facebook.
Paul