This is a very short service post for those Yamaha XV riders out there, who need "new" coils, which are readily available second hand, don't break the bank and just work. The Kawasaki 500 twins have been around forever and so have these coils. They are also 3 Ohm primary resistance, but have more secondary windings, which means they should have a stronger spark. Unfortunately, they don't fit straight away, hence you'll need a little adapter.
They also work well on older Guzzis, if you want something a bit more reliable/predictable than the cheap PVL ally can coils, which either run forever or fail within a few minutes of use.
So imagine this, your beloved steed (in my case a Yamaha TR1, but the
same will also apply to XV700s, late 750ies and of course 1100s), instead of
greeting you with the much beloved sound of grinding and crunching starter
gears, greets you with this noise
So it's disconnect the battery and take the left sidecover off time.
The name starter-"clutch" might be a bit misleading as it really is a
one-way-clutch and as you can see in the clip below, the clutch in this engine
is more an "open for everything" clutch. (Which is a great mindset in general,
but a bit problematic, when the clutch is supposed to drive the engine in only
one direction.)
As you can see, if you look at it closely, I already welded up the clutch
once, but this didn't quite yield the results I wanted. (The tacks on the back
sheered off.)
In order to fix this mess, we need a starter clutch (I am using a broken one,
which luckily I didn't throw away last time, a shaft for alignment of the
parts (your starter will do just fine, I had the shaft from a broken starter,
at least an angle grinder and a welder with some chest hair as the parts are
relatively thick. I will do it in a slightly more elaborate way on the lathe,
but that's really totally unnecessary as will come apparent over the course of
this post. (But it's been like four or five years since I modified my last
starter clutch and the first time to do it this way.)
All the parts as outlined above and an 18 tooth (XV1100) starter clutch, for a
regular TR1 with the original starter, you'll need the 19 tooth version.
The whole starter clutch is held together by the folded over lip on the back,
which I carefully removed on the lathe. A simple cut through the thin metal
shield perpendicular to the axis of rotation with an angle grinder would
achieve exactly the same result in a lot less time.
Peeling the metal shield back reveals the actual retainer plate and because everything is rather worn on this clutch, the gear can be pulled out.
Plate, springs and pins inside can be discarded and the gear and the clutch housing be reinstalled on the shaft, in order to trim it back substantially, so it can be welded, where the two parts meet up.
At this point I have to admit, I used my trusty lathe as a rotary head and cut the housing with an angle grinder as it is STUPIDLY hard.
And yes, I cut it too far towards the end initially, but we'll call this a lightening cut to reduce rotational mass and improve starter acceleration. 😅
After cleaning the two parts can be welded together, obviously while assembled on the shaft, so they are in proper alignment. I did it with TIG and quite a few amps, but probably it could have done with even more and probably some quenching in between, because I think I properly tempered the part. (Undid the heat treating/hardening of the steel.)
If you trim it down a little further, so it is the same diameter as the gear on the back (or less), you can make it small enough so in theory the start can be removed w.o. taking off the cover. (Not yet tested, but in my mind none of the other starter components in there can fall out...)
Additionally I had to ream the bronze bushing inside the gear of mine, because it always had been an overly tight fit on the starter shaft and while this is a good thing for alignment, having to install it by hammering it onto the shaft certainly isn't for either the starter OR the starter clutch. (Normally this isn't necessary, but the clutch shown was one of the cheapest ones I could - and apparently for a reason.)
And that's what it looks like, reinstalled.
Reinstall the cover, fill up with oil, hook up the battery and all the other bits you removed, cross your fingers, hope for the best ... you get the idea.
And then... nothing. It does help to hook up the wire to the actual solenoid. Probably to the great dismay of a bunch of Yamaha engineers, it works just fine without the extra clutch between starter and flywheel.
... but boy oh boy does the old girl sound fine, when she "just" fires up right. (Added bigger pilot jets and turned the air-screw in half a turn and she just starts like it's an EFI bike... perhaps even a bit better.)
So it does work remarkably well with the welded up / one piece drive sprocket. Even the initial repair would probably have been sufficient, if I am honest, but a few carb issues made starting a lot more difficult and the constant backfires eventually broke the welds. Not sure what would break this time, admittedly I am not overly keen to find out...
In the last installment "Geraet" passed it's inspection, got registered and I
took for the first few smaller shakedown runs. Whilst being "legal enough" to
take part in traffic, the old girl was pretty good from afar, but far from
good.
First on the list were the brakes. The pads were at least twenty years old and
definitely had seem some oil or other lubricant at some point and whilst
proper steel braided brake hose improved the overall brake performance quite a
bit yet those calipers were definitely dragging.
The blue Brembo pads, even though being the "budget" organic version already
made a huge improvement.
Next task: have a spare key made. I only had one original key and that was the
folding one, which felt distinctly wobbly in the joint and I was quite afraid
of breaking it off.
Both gearbox and final drive oil were also definitely well overdue for a
change, yet revealed no sparkly surprises.
As oil had been sitting forever in both the gearbox and final drive, I gave
them a good wash with some diesel.
And then admittedly after two or three rather spirited test-rides
the engine started to look like this.
And a bit more coolant and less oil on the other side.
In other words: waterpump-seal-time.
Now THIS is officially a lot of dirt and oil on top of the waterpump.
After a moderate amount of cleaning.
Doing the seal swap requires one special tool and I personally would highly
recommend you buy it at the shop you buy your seals too as the stock seal is
only about 9mm tall and the (improved) aftermarket one, over 11mm. Which
means, I had to alter the seal-driver to take those extra 2mm into account.
The pump shaft only needed a quick cleanup with a piece of scotchbrite to be all shiny again. The pitting is well within the coolant section and not where the seal runs.
Checking the height of the new seal.
So there's an official tool from BMW to drive the seal in, called the "BMW coolant seal installation mandrel", which has the following dimensions: Outer diameter 40mm Step diameter 28mm Center-hole 12mm Step depth 8mm - which I therefore changed to 10.5mm
Even though it may seem counter-intuitive, there should be about a 2mm gap, so when tightening the waterpump rotor bolt to spec, there is the correct pre-load on the seal.
Installing and aligning the pump, especially as there's an o-ring on the back, is a bit tricky, but nothing out of the ordinary, just expect to have liquid gasket on your hands everywhere.
As there's literally no way of ever cleaning the gunk out from on top of the water pump, I decided to trim it to size quite notably so riding in the rain would effectively wash the road dirt off.
... and only a few days later, I completed the first 1000km on the beemer.
At the time of writing it's almost a thousand more and whilst it is still not what I would call an exciting motorcycle, I'll admit that it is undoubtedly a very useful one. So useful that I'll soon have to replace the rear tire for the first time.
