Sunday 23 February 2020

Everyday TR1 - overhauling petcocks

The first rule of buying used parts is don't buy used parts unless you have to. The second rule of buying used parts is: follow rule #1.

Now if you buy two similar petcocks and one is notably easier to move than the other, this might be the moment, where you should consider either sending one back or buying an overhaul-kit as well. I initially did neither of those two things.

As you  can see, the diaphragm has swollen and was extending over the outlet a bit...

The fixed petcock - the standard kit comes will the hardware (even though I didn't use the petcock-to-tank ones) and it's a matter of ten minutes per piece.

If I had done it right away though, it would have saved me from having to repaint my fuel tank (again).

As we're already onto the subject of vanity, I also bought a set of shiny new mirrors. Not exactly because they are shiny, but because I wanted squarish ones again and in my old round ones, I couldn't see much, because of the vibrations.

Expect stories of me spraypainting the fuel tank rather soon, as I need the old girl back in service in a rather timely fashion.

Sunday 16 February 2020

Make Dre-XT-Stueck great again - couple more touch-ups and finally the correct choke knob (part 3.1)

... or the touch ups of the touch ups.

First was to get the carbs out and revert from 130/126 to 135/120, which is the stock setup for the XT600-model my carbs are actually off, but I only found that out later in the evening after going though some workshop manuals.

Followed by slowly increasing the number of holes in the airbox-lid to increase the amount of air going into the engine. (Remember it was running more than fine with this setup when it was just a 500cc engine!)

And then I finally found the correct choke knob in my "stash of valuable unused parts", i.e. the left-over parts bin. This one's from a TM38-86 and is about 6mm longer than the VM29/47 choke knob below. In order to make it work on the XT600 carb, the o-ring has to be removed.

Result? Starts first kick and pulls like a horse. The combination of more air and richer jetting definitely has released some ponies inside the engine and I have the nagging suspicion that the fuel consumption will go down, because I am not 100-percent sure anymore that the old cable-operated choke sealed all that well.

Sunday 9 February 2020

Finally fixing the Coronet-/Rhino-lathe cross-slide

Now this has been one of those tasks that has bothered me for a long while. My lathe's cross-slide was stuck at a weird angle ever since I bought it. Meaning that whenever I used the cross-slide I've cut a three to four degree taper.

As usual I would have expected the bolts to be something weird and wonderful straight out of Whitworth-land, but it turned out to be "just" a set of stainless M12-bolts, which the pre-owner had bought. 

Now if he had taken the time to remove the letters on the bolt-heads, I would probably never have had to take the lot apart. 

A set of fresh bolts, bit of oil and cleaning of the ways where the bolts sit and we've got ourselves a winner.

Which is a typical moment, when the heavy-handedness of the pre-owner reared its ugly head. Now I admit the amount of meat between the dovetails on the inside and the cutout for the hold-downs is rather limited, but the whole lot had fractured all the way over the last fifty or sixty years.

After some very thorough cleaning and with the gib-adjustment bolts removed, I put the whole lot in the vise and used an M8 nut as a spacer to pre-load the broken section.

After taking a deep breath and then turning my tig-welder up to eleven (210 Amps), I floored the pedal and this is where we're at.

As you can see, the crack extended round the corner, so I touched it up from this side as well. Before I did that I could see, that I had (almost) full penetration. The material is only 3-4mm strong at the bottom of the dovetail!

So the precision engineer in me knows that without the correct torque, the dovetail would at least need touching up, but in reality I must have been very lucky, because the cross-slide works all the way with pretty much the same resistance, so there's no loose or tight spots and as such I will call this a proper success!

Sunday 2 February 2020

Make Dre-XT-Stueck great again - couple more touch-ups (part 3)

With a 17°C day in February and some spares waiting for their install on the bike it was well about time to get the Dre-XT-Stück ready for the new season. So after a bit of cleaning up in the workshop, it was time to tackle a few minor jobs.

From left to right: a choke plunger instead of the cable operated stock (forgot to put that one one), a stock indicator mounting plate for the rear (as the MOT-man complained about it last year) and a sprocket support plate to stop it from wobbling around  and wearing out the gearbox-output shaft even more.

As my stock sprocket holder plate was also a bit chewed up and the whole kit actually cost the same as just a new holder, it made more sense to get the whole kit than just buying the original part form Yamaha. 

The additional plate goes over the end of the shaft and actually keeps it engaged nicely thus dramatically reducing the wear on the splines.

The indicators in the back had been fitted to a bent piece of stainless steel flatbar, which is a pretty good solution in order to get them out of the way of a set of panniers, BUT my MOT-man says that it might impose a safety risk to others... As I have to modify my pannier holders anyway, I thought I might as well tackle this bit.

Last thing on the list was to adjust the valves, because after touching up the valve seats they always need a bit of adjustment. Same here - inlets a bit tight, exhaust valves a bit loose, which worries me a bit more to be honest.

So what's the verdict: Dre-XT-Stück is starting to become a bit more lively now that the rings are bedding in. Actually so much so that I had the frontwheel in the air after taking off from a crossing a bit more spirited than was good for me.