With the attempt at welding the old case having completely and miserably failed, I decided to assess the situation and move my internals into a new case and while at it make an early health check.
Gave the cases a good clean up as they'd been sitting on the shelf for at least ten years in my various garages and check the oil-drain plug threads, just to be sure.
Next was the oil-pressure relieve valve, just to make sure it wasn't stuck. (It was not.)
As my BT1100/XVS1100 (V-star for the Americans) cylinders hadn't given me any
trouble over the last 40,000km, I decided to use them again. (Just in case I
have a spare set though.)
In the past I did this mod in a rather "medieval" fashion, by boring the hole
with HUGE holesaws, which nearly broke my wrist once. This time I went with an
80 grit flap wheel on a die grinder and let me tell you, this is simply the
best way aside from getting it done on a mill with a boring head. (My mill's
too small, in case you're wondering.)
Took about 5 minutes per bore and if you're a bit consistent, it's still reasonably round.
After all you only have to take out about 2mm on the diameter, so that was nice and easy. (It is rather dusty though, so one could postpone the cleaning of the inside of the case to after this step.)The finish is pretty spectacular though.
As the case had been sitting for a while one new OEM ball bearing was bought and it was painfully expensive.
At this point the cases were as far as I could get with them without the internals, so engine-out-o-clock it was.
So here is, where it was leaking from lately.
Temporary increase of workbench area.
Another one of the "glad I checked" moments along the line of this build, was when I removed the oil-pump screen and cleaned it very, very thoroughly.
Pistons and cylinders were looking very nice, so I wrapped some cardboard round them to prevent them from getting damaged during the crank removal. (Also I didn't have any new gudgeon pin clips, so I didn't want to remove the pistons except when I absolutely had to.)
Cases split, no real surprises except that the right side bearing seat had gone from "not very tight" to "rather loose" and the bearing had some signs of corrosion on it and decided to much rather stay on the crank instead.
Just for comparison, this is the sort of "finish" the holesaw left on the case, compared to what the flap-wheel does.
Pressing the crank out without removing the oil-pump sprocket is very straight forward, but while some people directly push on the bearing, I made a little spacer years ago.
Crank is looking very good with the rods removed. (Didn't even bother measuring, if it was out of round, because even the bearing shells look like new.)
Here you can see how this right bearing spun in the case, which was pretty much the only thing I found to be mechanically wrong with the engine.
Pressed the old bearing out of the new case as well as it become a bit crunchy from sitting so long.
Then put the engine case on a little hot plate (and had the new bearing in the freezer over night) - falls right in place.
Just to make my life easier, I then heated the other case half on the hot plate and sprayed the remaining bearing with ice-spray.
Dropped in the gearbox and then made another mistake by installing the clutch-fork guide-rod upside down.
Even managed to align it nicely 180 degrees out.
Literally with all the confidence I could muster at this point, I decided, it's f*cked already, might as well try and tack it in place.
The assembly then went moderately well. Started by pre-filling the oil pump as that helps a lot with priming it.
Circling back to the oil-leak mentioned during disassembly, I decided to try something new and fill up this cavity with silicone, so the rubber gromet had more surface to butt up against. (So far it's working.)
In order to install the right-side scissor wheel, there's a little trick in the form of the hole that's visible when aligning the dots. You can put a punch through and it'll allow you to tension the spring, making (correct) installation a lot more easy.
Clutch hub nut is tightened first, then comes the crank nut. Manual
suggests to use some leather to block the gears. It does work admittedly, but
the gloves don't survive the abuse.
In order to convert from the oil-level sender to an actual oil-pressure switch, the case needs to be drilled. I am going with an oil-pressure switch from a Volvo 240 with the classic B-series engine with a thread pitch of M10x1.0 and admittedly a bit of silicone around the base just to be sure.
In order to get the squish-gap a little closer - no base gasket, just some silicone. (Check clearances first though.)
Swapped the old ball bearings for some new C3-clearance ones and guess what, they really are less noisy as they allow for some ever so slight misalignment. (Most difficult part about this modification is to get the metal shield off.)
Time up the rear cylinder and be done with the first half of timing.
Other side is more of the same, except...
You have to turn the engine over 275 degrees to be at the right TDC. Guess who had sleepless nights etc. (Also with used cam-chains, the mark will not align perfectly.)
Quickly cleaned the (normally inaccessible) swingarm area and greased the bearings. Then attached the frame to the engine.
With all the timings triple checked, installed the camshaft bolts with loctite.
Safety wired the sprocket, because Loctite is nice, but getting the sprocket clean enough for it to definitely work is absolutely impossible.
Also wanna guess which finger of the lates gloves I wore had a little tear in it? 😂
Little something I wanted to do for ages as well: Stamp the cases with the correct TDC markings for each cylinder.
"Quick" re-assembly of the bike:
So I fired it up...
... and it only ran on one cylinder at idle. So I did *ALL* the troubleshooting.
Interestingly enough, the valves were sealing *JUST* well enough that if you spun the engine over quickly, it would actually build pressure.
Back to square two or something like that, fish the old XV700 heads out and get back to those.
Quick test-fire and it just check out the difference - sounds so smooth, when it's not firing out the exhaust.
Weirdly enough, I could sync the carbs perfectly via the idle screws...
... but not at higher RPMs. Turns out, I must have stretched and damaged one of the cables, whilst I had the bike lying on its side during the repairs.
Pulled out a new 2in1 cable, opened up the splitter and (gently) clamped it in the vise to use the tops as funnels to properly oil the cables.
Bit of heat-shrink on the adjuster as I found that rain-water finds its way into the cable otherwise.
But there's a happy end after all. Old girl cracked the 140,000km mark, is not leaking and running nicely again.
Which is a rather nice ending to this three week ordeal and I am mighty happy to report it's over.
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