feetupfun

Good to hear and welcome

Lots of people ride in competition trials events without using a scorecard. They just ride whatever line they want to challenge themselves with. Also lots of people enter the grade they feel comfortable riding and sometimes take a harder route to increase the challenge. I set lots of sections and my goal is to do it so that people can ride higher grade lines without going outside the gates for the grade they entered. Yes gate trials are great fun and they are also a competition. I love the mental aspect of gate trials in that the better you know your riding ability (and act on it when choosing gates), the higher you will place.

You've got me thinking. Doesn't the top triple clamp pull down against the adjusting nut?

Hi Dirk I'm in Gladstone, Queensland, Australia. We have an active old trials bike scene and have a great time. David

I don't know what tyres are available to you but if you can get a rear tube type IRC trials tyre it will be great on your TLR for trials. None of the other brands make tube type rear trials tyres. The Michelin rears are tubeless type and are more difficult to get to stay sitting on the bead seats on a tube type rim. The IRC is an amazingly grippy tyre like the Michelin. It is more sensitive to tyre pressure being too low than the Michelin as in the rear of the bike moves around if the pressure is too low. Where I live I can't get IRC rears for my twinshocks so I buy Michelin rears and trim the beads so they fit properly on my tube type rims.

I can advise you to say what country you want to register it in

To get milky oil out of the gearbox you drain the milky oil out the drain hole or by taking the clutch cover off and put dry oil in, go for a ride then drain that oil out then put dry oil in and go for another ride. Usually by then the oil is visually free of milkiness. If it is still a bit milky, drain it again and put in dry oil again. It's not a big deal/damaging/dangerous to ride with milky gearbox oil. The action of the clutch might be a little different to normal. The oil is designed to keep the water away from the metal bits by encapsulating the water as billions of microscopic globules. The water globules are why the oil looks milky to the naked eye.

$AU500 to $AU3000 depending on condition and location

Scorpa trials bikes originally had Rotax motors, then Yamaha motors, then they had financial problems and were bought out by Sherco. From then, they have had Sherco motors.

you can also use a DT175 A/B/C/D cylinder and head as a swap for TY125 cylinder and head and may be more easily found. The compression ratio is slightly higher than TY175 which some prefer anyway. Maybe say where you are located to assist you in your quest

I bought a Tubliss many years ago for the rear tyres on my trials twinshocks and ended up not even trying it because it was heavier than a tube. It's still on my shelf.

Depends on what you define "manufacture" and "in house" to mean. Yes. Some brands share engines with other brands. Current examples are Montesa/Honda and Sherco/Scorpa.

Yes something weird happened a few years ago that changed that. It previously showed if you were a financial supporter of Trials Central or not. Now we are all just Newbies!

In Australia, riding Motorcycling Australia sanctioned trials competition events, helmets are required to meet the same standards acceptable for on-road motorcycle riding, which in Australia includes helmets made to European standards, Australian standards and the popular USA standards Snell and DOT. There are helmets available that sit on the top of your head that are legal on Australian roads and they would therefore be legal for use in MA trials competition. Here is an example of such a helmet https://www.easyr.com.au/m2r-rebel-shorty-helmet-w-quick-release-matte-blac I wear a normal trials competition helmet because I think they are a good balance of protection vs comfort vs ergonomics.

Modern premix and injection two stroke oils for road use are designed to be "low smoke" to avoid making visible emissions and they achieve this by resisting burning during combustion of the fuel, but the penalty paid is that they condense/accumulate within the exhaust system as a gooey liquid. If the fuel/air mixture is well managed on your Alpina and you run a modern premix oil at 40 to 1 or 50 to 1, the exhaust gases will be invisible. If you want to get the best fuel/air mixture control, run with a new modern carby jetted correctly. I run a 26mm OKO from Mid Atlantic Trials on my Alpina and it runs super sweet with perfect jetting straight out of the box.

Further to what Woody said, having just converted my series 1 (1968) model 49 to having the later type magneto cover, I found that not all the later clutch cover types (with an adjusting plug) provided enough side clearance for the clutch spring adjusting nuts. I was just about at the point of replacing the clutch hub with one with shorter clutch spring pins, when I found a clutch cover that was the same shape inside as the original 1968 type clutch cover except that it had a pushrod adjustment plug in it. My point is don't assume that a later (boot-heel shape) clutch cover will necessarily fit over the clutch spring retainers in your Lobito. It has a better chance of fitting if you have the pin type clutch spring retainers. I found the clutch action with the original worm drive actuator was quite good (with aftermarket clutch plates and just enough spring preload). I changed my magneto cover to the later type so I could fit the model 49 motor in a later model frame with side frame rails under the motor. With the clutch cable retainer underneath, it interferes with the left side lower frame rail on the later Sherpa T/Alpina frames.

Judging how much oomph for obstacles is a skill that comes with practice, no matter if it's a 125 or a bigger engine. The concept of riding a 125 to start with is that the relative lack of power helps you to more quickly learn good riding technique. As for jumping up things, it is safest to initially "over oomph" things then reduce the "over oomph" progressively until you oomph "just enough".

Think about what happens as the forks extend. Those little springs cushion the end of the fork extension travel. They are important when riding up steep hills.

pretty sure the standard needle nowadays is rubber-tipped https://amalcarb.co.uk/shop

No argument about why two strokes need crankcase seals but we are not talking about crankcase seals, we are talking about seals for the internal parts of the crankshaft main bearings. Rubber - sealed bearings are used to help the bearings last longer in motors that have poor ventilation/lubrication of the crankshaft main bearings.

The plastic float needle in those carbies does not give a reliable seal and can become roughened where they touch the seat. To see the roughness I need to use a magnifying glass and good lighting. However while that can cause fuel to fill the crankcase overnight if the fuel tap is left turned on, it will only be a tiny trickle, not a gush, and if the tank tap doesn't pass, is generally not an issue. Maybe test yours with the float bowl removed and you holding the float up when you turn on the fuel tap, to see if that reveals what is going on. My first thought is that perhaps your tickler is touching your float

I confess to being a twinshock trials bike train-spotter. TY250 forks have 34mm diameter tubes and TY175 forks have 30mm diameter tubes. TY250 forks overall are about 20mm shorter than TY175 forks, which is fine on a TY175 because the standard setting on a TY175 has the tubes about 20mm through the top clamps. The clamps are the same for both apart from the size of the holes for the tubes. Yes it's a common and good mod. I don't have vernier caliper eyeballs and it can be hard to measure fork tube diameter using a photo, but I could easily tell with yours because they look to be bigger than 30mm and TY250 fork caps have an internal hex and TY175 caps have an external hex and the sliders are the right type.

From the photos it looks like it's got a mixture of brake backing plates and wheel hubs from various DT175 models and TY250 twinshock forks and triple clamps. All quite suitable for trials use. The frame number means it is based on a competition TY175 model frame from 1977 onwards. Maybe take the magneto cover off and see if someone has fitted a TY175 flywheel and ignition. They can be made to fit under those plastic covers with a bit of trimming of the cover and the flywheel weight.

So it looks like you have a TY175 rolling frame with 1978 DT175E wheels and engine. If you post photos of the complete bike and at least the first half of the frame number it will allow for an ID of the frame and the other components. As for the gearing, one of my TY175s had a 1981 DT175G motor (which is very similar to your motor) in it and first gear was fine for trials sections but second gear was like third gear on a TY175. It would be easy to get your first gear to work well for trials by selecting a suitable front sprocket, probably 13T with the 60 rear. I think mine with the DT motor was 12/54. Putting a TY175 gearbox into your engine is a lot of work and expense and if it was mine, I wouldn't bother because I don't use anything but first gear in sections and the DT gearbox makes it much better to ride between sections and trail riding. That DT175 motor is actually pretty good for trials use. The porting of the DT175 motor is pretty much the same as the TY175. The port timing is the same but the ports in the DT motor are more squared-off in the corners. The DT175 motor has higher compression than the TY175 which is something that some people do to TY175 motors to get more grunt. The standard carby on the DT175 motor works fine for trials. The biggest difference in the motors is that the DT175 flywheel is a fair bit lighter than the TY175 flywheel. Some people lighten the TY175 flywheel and for experienced trials riders the DT175 flywheel would be fine. For novices it would be a bit easier to stall with the DT175 flywheel.

OK based on you posting photos showing the backing plate at both ends of it's rotational adjustment range, I suspect that you might not be approaching the task the right way. Maybe I'm off track here. How about you say what you have tried doing so far and what the status of the points is? Are they new? Are they the existing points that worked OK earlier?