many thanks for your response. This came with the bike & there is a slight gap where exhaust flange isn’t sealing against barrel, not great photos but looks like due to exhaust flange not being able to rotate it doesn’t seal properly. Next question is what would be the best solution for this?
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Maybe the header pipe is bent. There is meant to be a metal crush sealing ring in there to seal against the flange. The flange needs to be quite close to being parallel with the mating surface for this sealing ring to work. When these header pipes are being fitted new, the first thing to do is fit the header pipe up fully to the cylinder then make whatever changes are needed to get things to fit. I remember fitting a header pipe that looks a lot like yours and had to reshape the header pipe (heating it with an oxy torch) to get the rear end of the header pipe in the right spot to fit to the front end of a WES mid box.
new to forum & looking for guidance on install of stainless front/down pipe ( unsure if I can mention manufacturer on here)? for 78 Yamaha TY250 T/S. Website I was looking at mentions a flange & using bolts instead of studs? Any help appreciated, many thanks.
Depending on the shape of the pipe and if it has a fixed flange or not, it may need to have bolts used where the pipe flange bolts to the cylinder, instead of studs and nuts, to allow the pipe to be fitted.
Some TY250 twinshock cylinders have exhaust flange mounting holes that are M6x1.0 threads and some have M8x1.25 threads.
The standard arrangement from new is studs and nuts.
The standard exhaust pipe flange can rotate on the standard pipe. Some aftermarket pipes have a fixed flange.
Thanks for that. I did find that manufacturers list an XT225 sprocket as having the same offset as a TY250 sprocket and happened to have one from an XT. The sprocket that came on the TY has about 5 mm too much offset. I did some measuring and my numbers are slightly different from yours but also found that different manufacturers (on Amazon) list minor differences in sprocket thickness. That seems odd.
If you had an OEM sprocket to measure, why did you not just compare it with the one causing the issue on the bike?
Were the original sprockets aluminium? This one is magnetic and all references I see to the brand on line are all old so it could be a 25 year old aftermarket sprocket. Is the OEM offset listed somewhere?
Everything looks straight as far as I can tell with a tape measure, eyeball and the bike together. One odd thing is that the paint is rubbed off the swingarm where it touches but I would expect to see it more torn up from the chain. If I mis align the snail axle adjusters by one step, I get about 2 mm clearance.
Were the original sprockets aluminium? This one is magnetic and all references I see to the brand on line are all old so it could be a 25 year old aftermarket sprocket. Is the OEM offset listed somewhere?
Everything looks straight as far as I can tell with a tape measure, eyeball and the bike together. One odd thing is that the paint is rubbed off the swingarm where it touches but I would expect to see it more torn up from the chain. If I mis align the snail axle adjusters by one step, I get about 2 mm clearance.
Yes original is aluminium. I'll measure the offset on an original sprocket
At the end of March I bought a TRS One RR 300 cc - 2023 new.
I got a very good deal and visually it looks very well finished compared to the Vertigo ( Finish close to the GasGas ).
I did not ride it yet as I am abroad fro business. Will be back this week and hopefully ride it in the week end.
What are your thoughts / experiences on this bike, please?
Thanks!
Kasty
I've ridden a 2022 300 TRS One RR recently while getting it running well for a friend. Yes they are very well-made. It had lots of mumbo on tap. The handling, brakes, suspension and steering are excellent. Initially the footpegs felt further forwards than what I am accustomed to but the feeling went away after a few minutes riding.
The couple of books I have at home say the first Sherpa T was based on the Millers modified Sherpa N. It's hard to find any information on the Sherpa N or the Matador, so it is difficult to work out what differences there are in those two models.
One thing I have noticed is that the standard Sherpa N has a very long horizontal rear frame loop (for a dual seat). The prototype Matador, Mk1 Matador and Mk2 Matador all look like a Sherpa S frame to me because of the steep short rear frame loop. On the Miller Sherpa T prototype, the rear frame loop and shock mount area doesn't look like any of them. It's rear loop is short and steep but the tubing looks smaller diameter and the gusseting at the shock mounts is very different.
The photos I'm looking at are in Bultaco Todo un mito and Don Morley Spanish trials bikes. I've also looked at two frames. A 5 speed Campera frame from 1966 which I think is an M21 and a 1963 M3 Sherpa S frame.
Hi I am looking for help/information about my 1980 Fantic 200 rear kick please.
I am in the process of sorting out my Fantic 200 and the distance between the shock mounting points is 203mm from inside frame mounting point to inside mounting point at the top on the frame and 220mm for the same points on the swinging arm this does'nt seem right to me and nothing seems to be bent, even with the wheel in and done up the bottom distance is still 215mm so the rear shocks are not parallel. I wonder if someone has replaced the swinging arm with one from a different Fantic.
Any views or help would be appreciated.
Thank you.
It's fairly common practice on multiple brands of twinshock trials bikes to have the top mounts closer to the mid-line of the bike than the bottom mounts are. It was done to make the bike slimmer where it counts
Hoping I can get some replies here! I’ve have a ‘74 TY250 for about a year. Took it out for a single ride other than up and down the road and around the property (moo), it was so much fun. Can’t wait for the upcoming season.
two questions:
1. i purchased it for $1300. It came with an entire other bike’s worth of parts. Wheels and tires, gas tank, etc. All except the engine that was destroyed when it got wrapped around a tree. What’re your thoughts on that price for the bike and parts? I thought it was a steal.
2. I get voltage spikes on throttle and keep blowing bulbs. I replaced the condenser, contact breaker, and spark plug today and the thing fires up like it’s brand new. But still experiencing the voltage spikes. Any ideas? Maybe I’m just dumb and incorrectly wiring the lights, but also fear it could be something more systemic. Would bad magneto coils lead to this or would the condenser catch that? Any tips for trouble shooting this would be greatly appreciated.
best from Montana,
Connor
Yes that is great value. They are a fabulous motorbike.
The ignition system is not connected to the lighting system. Each has its own stator coil in the magneto.
Blowing 6V bulbs was standard back in the day for TY250A. Fitting 12V bulbs was one way to avoid it, but the lights then became dimmer. They came with no voltage regulation on the lighting circuit so as the RPM rises, the voltage rises.
Nowadays there are a myriad of options for the lighting circuit on motorbikes.
My memory of riding the big-wheel Beta 80 is that it was OK for me at 5'10" but I would think it might be a bit cramped for someone tall. The motor was easy to use in sections.
Modern 125 two-strokes are excellent.
The modern mecatechno (electric) trials bike is extremely light.
I've just done a top end decoke on a friend's (low hours) 2022 TRS 300 and was astounded at how tenacious, dry and thick the carbon deposits were that completely covered both the piston crown and the inside of the head. It ranged from 0.25 to 0.5mm thick. The tenacity and hardness of the carbon in this TRS reminded me of the carbon that formed in my 1970s air-cooled two stroke enduro bikes running on 20:1 castor oil premix.
Sure enough, when I then asked the owner what premix oil they use, they told me it is castor oil based.
I'm accustomed to seeing soft, wet smudges of carbon that cover about 40 % of the piston crown on my 2 stroke trials bike pistons.
Is using castor oil premix in modern trials bikes common practice?
Talking to a couple of mates and we have no idea what the horizontal 'flat surface' on the engine case is there for. It's not on the earlier round case models, any ideas??
When that casing is on a 348 motor there is a screwed plug there.
Thank you feetupfun, your information and pics are wonderful. I am now using 360mm Betor gas shocks and wanted to understand how the original Betor shocks limited travel.
The new shocks 360 with 95mm travel just barely clear new white plastic fender.
Another factor in rear tyre clearance is that the rear competition tyres in the 1970s were nowhere near as tall as modern competition rear tyres
Need tech specs please.
1972-3 Sherpa model 92b.
what is the OEM shock travel?
Not wheel travel, not axle travel
Eye to eye, shock travel dimensions, exposed chrome shaft length when fully extended?
So here's a photo of a Spanish Betor trials shock from back then. I have no way of knowing if its actually from a model 92 or not but I do have quite a few and they all have the same length shock shaft. Some have this type of seal retainer and others have a different type of seal retainer.
Need tech specs please.
1972-3 Sherpa model 92b.
what is the OEM shock travel?
Not wheel travel, not axle travel
Eye to eye, shock travel dimensions, exposed chrome shaft length when fully extended?
My memory is saying 3.25". I'll have a look to see if I have one to measure
I put the case together this afternoon everything seems to be ok except for the kickstart mechanism. When the kickstart shaft is rotated (to simulaye a start) the the gearshaft turns (as expected) but there is a clicking noise when the kickshaft is rotated back to its home position.
Does anyone know the reason for this?
The ratchet mechanism you can clearly see in the photo should click as the kickstart lever returns towards the stored position. Just before the lever reaches the stored position, there should be a cam or ramp that moves the ratchet teeth apart.
If not for the ratchet mechanism, the kickstart shaft would be rotated by the motor when the motor starts.
TY 250 T/S front/down pipe - Stainless
in Yamaha
Posted
Maybe the header pipe is bent. There is meant to be a metal crush sealing ring in there to seal against the flange. The flange needs to be quite close to being parallel with the mating surface for this sealing ring to work. When these header pipes are being fitted new, the first thing to do is fit the header pipe up fully to the cylinder then make whatever changes are needed to get things to fit. I remember fitting a header pipe that looks a lot like yours and had to reshape the header pipe (heating it with an oxy torch) to get the rear end of the header pipe in the right spot to fit to the front end of a WES mid box.