feetupfun

We have to use lanyard killswitches for trials competition here and popular lanyard kill switches are made by Leonelli and Jitsie and have a magnetic action https://www.google.com/search?q=leonelli+magnetic+lanyard+kill+switch&rlz=1C1GCEB_enAU911AU911&oq=leonelli+kill&aqs=chrome.3.0j69i57j0i22i30l3.11568j0j7&sourceid=chrome&ie=UTF-8&safe=active&ssui=on All my bikes require the killswitch to earth out the LT circuit of the HT coil to stop the motor. These kill switches I mentioned have two wires and either of them can be used to connect to an earth point. It's best to run the earth wire from the kill switch to an earth point on the main frame of the bike, to avoid sending current through the steering bearings, which could otherwise damage the bearings. Most people connect the kill switch earth wire to where the HT coil connects to the frame. Most people connect the other wire from the killswitch to the LT wire near where it connects to the HT coil.

If the reason for your conundrum is that the gasket is acting as a weir then you can test for this by draining the gearbox and seeing if the dipstick is still showing a level

Yes there are listings for when different models were sold but beware that the sales timing was different in different parts of the world, they didn't work to calendar years and they changed things without changing the model number, so it can get a bit confusing to think in terms of the calendar years. Here's one list that may help. There are plenty of other lists available on-line. They don't all agree. https://newellmotorcycles.com.au/pages/bultaco-history

Yes that's the drain hole

On the motor I took the photo of, the drain plug drains from both the clutch casing and from the gearbox. The drain plug hole is open to both sides. I suspect that this could be where your problem lies. For some reason your drain plug may not be draining both compartments. Before I went and found the engine casing to take a photo of, I was expecting that there would be a dedicated hole near the bottom to let the oil levels equalise, but Yamaha have designed it for the levels to equalise via the the shift drum hole and the shifter shaft hole, both of which have rotating components that are a loose-enough fit for oil to pass through.

The first "350" Alpina (model 99) was 325cc and at the time, all Bultaco San Antonio 2 motors 250cc and bigger were 60mm stroke. The "350" Pursang, Alpina and Sherpa T were all 325cc. They didn't want to go any bigger in the bore for that stroke so that's where the 325cc came from. When they wanted to make the Pursang 360cc instead of 325cc, the stroke was lengthened to 64mm. This required larger crank wheels so when they went to 64mm stroke, the crankcase design also changed. The "350" Alpina and "350" Sherpa T also went to the same larger crank wheels design however the Sherpa T stayed at 60mm stroke (325cc) while the Alpina went to 64mm stroke (350cc). The 325cc Alpina (model 99) was sold in 1973. The first 350cc Alpina is the model 116 and was sold in 1973/74. Later Alpina "350" were all 350cc. However, Bultaco are reknowned for changing things in the design of a model during the production period so anything is possible (such as a 325cc motor in a model 116) which is one reason for why when you order engine parts from In Motion they want to know the engine number, not just the prefix.

My first thought is something that is acting like a weir between the gearbox and the primary drive compartment. There's another test you can do before taking the clutch cover off if you want. If you drain the gearbox via the drain plug and yet still have a high level when you dip the primary drive compartment, then that will prove that there is something stopping the oil level from equalising between both compartments. If there is something acting as a weir, it's possible that whoever built the engine made their own gasket and didn't put the bottom hole in the gasket for one of the passages where the oil flows back and forth between the gearbox and primary drive. There are also other possibilities but no matter what it is you or someone will need to take the clutch cover off to find out what is going on

Here is where 1000 ml comes up to on my A model. I put masking tape on the dipstick so the oil would be visible in the photo. The oil level is 12mm from the end of the dipstick. I dipped it without screwing it in.

There are a few possibilities for what you are seeing: 1 Not all the old oil was drained out. 2 The bike was not level when the dip was taken. 3 Not enough time was allowed for the oil to flow out of the primary casing and into the gearbox before the dip was taken. 4 There is a problem with the oil flow path between the clutch casing and the gearbox (maybe gasket covering the passage).

Photos for Tillerman6

I'll post up a photo of an A model dipstick here tonight

I figure that some people don't do them up tight enough because on a TY250D I bought, it developed a base gasket leak that stopped leaking when I re-tightened those nuts

The 250 is 10kg heavier than the 175 because the 250 motor is 10kg heavier. The 250 feels light for a 93 kg bike which is a normal weight for a standard 250 twinshock. They didn't sell so many Yamahas by accident. They were designed to appeal to Clubman riders and they still do. The 250 is 16 HP and the 175 is 12 HP. They both pull well and in proportion to their capacity. They both have a ridiculously wide useful RPM range. The 250 is a short wheelbase and the 175 is an extremely short wheelbase. All mods are entirely personal preference. Both are very good to ride stone stock. Many people lengthen the 175 to get a light full-sized bike.

https://www.amazon.com.au/3-5mm-Metric-Right-Thread-0-6mm/dp/B07B4C9TH8 I haven't check the pitch of the Bultaco spokes yet but if they are 0.6mm then I'm thinking of getting some of these and some blank nipples

Heat those nipples with a fine flame and they will fall apart. Any remnants of aluminium can be removed from the spokes by soaking the threaded end in a mild acid

For many years I bought replacement aluminium Bultaco nipples from Bultaco parts people but I think that the remaining stocks of them have been used up by now. It seems a waste of the spokes not to reuse them because the stainless steel Bultaco spokes are/were very nice. For my most recent Bultaco restorations, I gave up looking for aluminium nipples and bought new stainless steel spoke kits, which are quite economical nowadays.

99 is like a square steel funnel with flat filter horizontal at the top. 115/116 has a flat filter in a vertical plane in a fibreglass housing They changed the design to avoid having to remove the tank/seat to service the air filter

No I don't know of a special replacement footpeg mount made to exactly fit your frame. What's wrong with doing weld repairs on the frame anyway? It's not unknown that trials bikes newer than yours have needed weld repairs

Yes repair if you are worried. Only you know your own level of acceptable risk. If it was mine and depending on how much life is left in the rest of the bike I would either fit new peg mounts or let them wear down another few mm. Pre-formed peg mounts are readily available and you could fit them a bit higher than original.

Your idea of a swap sounds sensible. I've bought quite a few trials bike fuel tanks from overseas (UK, USA and France) and I'm not alone in doing that so I guess postage cost is not prohibitive to a motivated person. Your tank would be amongst the best (unrestored, original) of its type I've seen. If your tank was here it would sell quickly for $AU200-$300 (GBP 100-150).

Shane it would probably be good to put an ad for it on the Trials Australia website

I would love to be able to buy that tank from you or swap for one of my 115/116/137/138 tanks, but there is a law preventing sending second hand tanks from the UK to Australia.

The photo I posted is a 115 and the cylinder looks different to your 116 because it is a 250 and that is how 250 cylinders looked until around 1974. After they changed the 250 cylinder finning design to a more open spacing, the 250 then looked very similar to the 325/350 cylinder. The common name for motor in the photo I posted is round barrel because viewed from above, the fins form a circle. The round barrel 250 has poor heat rejection capabilities because the fins are too closely spaced. Bultaco realised it was a problem and when the 325 came out it was made with wider spaced fins that form a square when viewed from above. The 250 was later changed to a similar finning design to the 325. Other than the motor capacity and the colour of the stripe on the tank, the 115 and 116 are the same.

The 85/99 tank you have is more valuable than a 115/116 tank

This what your Alpina tank shape should be to fit your frame. This is a 115 which is the the 250 version. The 115 and 116 have the same shape tank. The 250 has a silver stripe and the 350 has a yellow stripe