Trials Australia Forums

Mount it .... Straight to the pool room ... Don't dare risk such beauty putting it on a bike!

Hi Everyone,

Kurt wrote:I'm using a 2 jaw puller unsuccessfully at the moment, nothing as fancy as that ball joint splitter.
I used a bearing splitter on the crank gear.
Hopefully a few heat cycles and WD40 will eventually loosen it.

Kurt, did you get the sprocket off? If not it might be possible to split the cases, get the Kickstart shaft out of the way and then use a bearing splitter?
Your is a bit of a bitsa, the flywheel cover looks to be off another model? Perhaps this is the right one, happy to swap if you want?

Also, does yours have a GOLDEN flywheel?

David, I really like the wrap, remember this airbrushed one of mine?

Do you or anyone else think a wrap might fix this:

Not sure how I did it but I have had no success gluing the piece back in, superglue, rapid fix and all of the other plastics glues I have don't work. The piece varies from 3 mm thick to 6 mm thick and is a neat fit back in the guard but it is glossy in the break, gouging the edge to increase the surface area did not help! Sikaflex has been the best but the piece falls out when riding!

On another note back on lathes, I have never had a good boring bar so I bought this secondhand one that turned up today:

Have you tried MEK (methyl ethyl keynote) , as it is a solvent and should “dissolve/melt” the two parts together.

Phil

Greg Harding wrote:Hi Everyone,

David, I really like the wrap, remember this airbrushed one of mine?

1627875445388.jpg

Do you or anyone else think a wrap might fix this:

1627883274462.jpg

Not sure how I did it but I have had no success gluing the piece back in, superglue, rapid fix and all of the other plastics glues I have don't work. The piece varies from 3 mm thick to 6 mm thick and is a neat fit back in the guard but it is glossy in the break, gouging the edge to increase the surface area did not help! Sikaflex has been the best but the piece falls out when riding!

1627883274462.jpg

On another note back on lathes, I have never had a good boring bar so I bought this secondhand one that turned up today:

1627883330606.jpg

Greg that is a very nice boring bar. Good score there .

Nice to see the airbrushed TY guard again. I had forgotten about it so please retell the origin/creation story?
Is that rear guard photo showing a real mudguard ??? It looks like it's made of cake icing. If so, no wonder the glue won't stick. If it's just an illusion and it is actually made of fibreglass, there seems to be a distinct lack of glass fibres in it. What is really going on there?

Only one way to fix that mudguard - Epoxy resin fibreglass.

The sprocket is still attached to the shaft unfortunately.
I will resort to David's suggestion of the angle grinder I think, I tried your suggestion of putting it into the low heat Tasmanian night with the puller still attached but to no avail.

Yes very much a Bitsa I came across the side cover cheap as it didn't have one initially. I think yours may be more correct than what is on it but it fits.

Golden flywheel here also, I assume they made them out of bronze for a bit of extra inertia provided by the denser material while having a smaller flywheel?


An interesting story on the flywheel is I got the primary coil rewound by small coil rewinds in Geelong but he couldn't fit the coil back into the same spot so he shifted it around 60 degrees so it was still being activated by one of the magnets at the right time and fitted it there.


Have you tried a PVC glue on the plastic mudguard Greg?

A couple of years ago I pulled my KT250 apart and when I got it back together and running again this year, the float needle kept sticking to its seat. Not just when I first started it, but even after freeing it up and riding around for a while it would then stick shut again. If I hit the float bowl I could get the fuel flowing down into the carby again but having to keep doing that got annoying pretty fast.
So I pulled the float bowl off and sure enough there was some fuel gum on the float needle and on the needle seat. At that point I was thinking that the fuel had formed a gum while the carby was drying out off the bike and I should have cleaned it out when I put the bike together.
So after that bit of attention, the carby behaved itself during the next riding session.
The next time after that, I went to ride it and once again the float needle was stuck to the seat and kept getting re-stuck after being freed. Hmmmm... more thought needed.
At this point I had an idea that maybe the fuel tap was not fully sealing off and while the bike was parked up in the shed, maybe fuel kept getting fed to the float bowl, replacing the fuel in the bowl as it evaporated, and leaving a gum behind.
So last night I did an experiment to test the fuel tap by running a piece of fuel hose from the tap into a clean yoghurt container. Sure enough this afternoon there was an oily trace in the container at the end of the hose where premix had been evaporating.
I then pulled the KT fuel tap apart and the conical plug is definitely worn (photo) so no wonder it leaked past the plug.
I then fitted a rebuilt TY tap and cleaned the float needle and needle seat again (photo). I also cleaned the pilot jet while the bowl was off.
I guess the proof of the pudding will be what happens after the bike has been parked up for a few weeks.

Hi Everyone,

David Lahey wrote:
Nice to see the airbrushed TY guard again. I had forgotten about it so please retell the origin/creation story?
Is that rear guard photo showing a real mudguard ??? It looks like it's made of cake icing. If so, no wonder the glue won't stick. If it's just an illusion and it is actually made of fibreglass, there seems to be a distinct lack of glass fibres in it. What is really going on there?

David, I am not sure about the story of the airbrushed guard except it came to me in a Basket of bits and there was nothing else that resembled the paint job.
The TLAh mudguard is plastic, here is how it came to me:

Pretty sure it is genuine from one of these:

Does this photo help you understand?

Still have no clue how I broke it, my usual trick is to snap them in half next to the rear mounts?

Jools wrote:Only one way to fix that mudguard - Epoxy resin fibreglass.

Jools, do you think fibreglass resin with stick to it? All of the glues I have tried roll off when rubbed with a finger and only seem to be a cleaning agent.

Kurt wrote: Have you tried a PVC glue on the plastic mudguard Greg?

Good thinking Kurt so I tried today, scraping the plastic guard to clean the surface feels very similar to scraping Poly Vinyl Chloride (PVC) pipe. However bending the guard is more reminiscent of how my kayak behaves and it is Polypropylene. Glue test:

Left it in the sun for a couple of hours (should be almost instant with both parts PVC) and it just rolled off:

Phil 850 wrote:Have you tried MEK (methyl ethyl keynote) , as it is a solvent and should “dissolve/melt” the two parts together.
Phil

Phil, can you be a little more specific? Is this what you mean?

This is the stuff you spray onto plastic to soften it and you then have 24 hours to paint before the pastic hardens again. When I googled (Methyl Ethyl Keynote) which sounds (So naturally occurring and good for the environment), I got a lot of warnings about it being banned. The other useful bit was that it dissolve plastic! How should I use it and how do I control it to melt the join only?
Thank you for the help everyone!

Kurt wrote:Golden flywheel here also, I assume they made them out of bronze for a bit of extra inertia provided by the denser material while having a smaller flywheel?

IMG_1692 (2).jpg

I wondered about that too Kurt but there is only a small difference in density between steel and bronze.
Tin Bronze 7.9% to 14% SG = 7.4 to 8.9
Aluminium Bronze SG = 7.7
Phosphor Bronze SG = 8.88
Carbon Steel SG = 7.8
Lead SG = 11.35
There's gotta be another reason for the "gold" flywheel.

While I suspect that the 348 crankshaft is the same as the 247, the 348 motor has a different magneto flywheel to the 247 in that it is not "gold" and is called a "Dinosauria" or similar.
The 348 motor also has a large steel flywheel on the drive end of the crank and I'm wondering if the 247 also has a flywheel on the drive end.

Another thought about flywheel materials is that I suspect that some of the external cup magneto flywheels I have seem to be made from lead and some seem to be made from aluminium

Kurt wrote:An interesting story on the flywheel is I got the primary coil rewound by small coil rewinds in Geelong but he couldn't fit the coil back into the same spot so he shifted it around 60 degrees so it was still being activated by one of the magnets at the right time and fitted it there.

I had a sort-of-similar experience when working on Mark Casswell's TY175 many years ago.
I had been trying to get the magneto flywheel off it for days using heat/cold while it was under load with a puller and when the taper finally let go, the flywheel and puller sprung off so fast it slipped through my grip and fell onto the concrete. The flywheel cup was slightly dented in one spot and one of the four magnets was smashed.
I found another flywheel to use in Mark's TY175 motor but I managed to put the damaged flywheel to use on a DT175E motor that was fitted with a TY175 crankshaft by removing the broken magnet and the opposite magnet to the broken magnet. One of the two remaining magnets was the one that is used for the ignition so worked fine in that motor. Would not be good for powering lights though.