I'm assuming you are asking why the mounting holes do not perfectly align with the muffler sitting there.
How close does it get to the mounting holes lining up if you lift the muffler?
If that's not enough, you could loosen the exhaust mounting bolt near the airbox and loosen the bolts at the cylinder and try moving the exhaust upwards.
If that's not enough you could bend the end section of the exhaust upwards.
Brand new to trials. I have a 04 Scorpa 125 which has a stop button. Just wondering if there is much difference between the Apico & more expensive Leonelli ones used on modern Scorpas before I buy one?
The Leonelli has a longer red plastic bit that houses the magnet, so is a bit more easily bumped off its seat.
They have opposite magnetic polarity.
I haven't looked close enough to see it the magnets are held in place differently. Having the magnet pop out of the holder seems to be a fairly common problem, based on how many people have asked to borrow a lanyard after theirs lost its magnet.
I didn't notice a difference in price between them.
Yamaha sy 250, I haven’t tried birketts yet I’ll give them a ring on Monday see what they say, apparently Yamaha stopped making them so it’ll be old stock if I’m lucky enough to find one, or if anyone has had any luck with a suitable alternative
There will probably be an aftermarket rod kit available because the TY250Z motor is based on the YZ250 motor of the same era (ie probably the same conrod)
It sounds like you haven't pulled a motorbike engine apart before. The Cota 348 is far from being an easy one.
To get that casing separated on many other bikes is straightforward. The primary drive components are removed, the shifting components are removed, the gearbox output sprocket is removed, the ignition flywheel is removed, the shift drum indexing plunger is removed. All the fasteners holding the halves together are then removed and the crankcase halves are separated.
Cota 348s have a few unusual things that can prove to be more challenging than on most other bikes.
The drive gear on the crankshaft is on a taper that can be very difficult to release.
The sprocket is on a taper that can be very difficult to release.
The gearbox components are positioned precisely left/right with shimming that can fall off the shafts during disassembly.
The crankshaft seal holders, gasket thicknesses and shimming are what positions the crankshaft in the right spot left/right and provides correct end float.
If the reason you asked this is because it is hard to find B7ES plugs for sale, there are other brand plugs that can be used in place of the NGK B7ES.
If you only ever use your TY250 for trials type riding you could probably get away with a BP7ES but if your riding involves sustained riding under load then you are at increased risk of heating up the piston crown compared with a B7ES.
Those nuts are on the ends of bolts that hold the two centre casings together. The other ends (inside the clutch compartment) may need to be held to retighten them.
As for the crack, there is a common mode of failure with 348s caused by the kickstart shaft being rotated too far during a kickstart stroke. This usually punches a hole into the magneto compartment and is not a big deal. The marks on your inner casing and the position of the crack does not look typical for the damage to be caused that way.
I'll take a guess that someone has attempted to kickstart the bike without the magneto cover in place. Because the kickstart shaft loses it's outer support when that cover is removed, kicking it with no cover in place could cause a crack like that.
The crack is fixable by welding and to do it properly, requires disassembly of the motor (removal of the cylinder and separating the left and right inner casings).
Rather than welding, you may be able to source a second-hand RH inner casing.
Whether it is worth fixing or not depends on many things that you haven't mentioned.
All these videos of Trial GP and the elite riders may well be scaring off a whole lot of people, just as the contemporary video I watched in the 80's did me. At the very least they may well be creating people like me who want to do all the cool tricks, even though we have absolutely zero practical use of them. Not productive for developing low-intermediate competition riders!
We have run lots of public trials riding displays and static displays at rural shows and swap meets with videos running and this thing about the videos is one of the things we have got down to a fine art. We only ever show videos made at our own trials events. This way people not familiar with trials have a look and think to themselves "wow they are a gumby lot. I could do better than that!" Of course when they do turn up for a ride we make sure we have suitable sections for them to ride as they discover that it actually a fair bit harder to do than how it looks on a video.
The big growth in rider numbers for us in the past couple of years has been people wanting to improve their skills in Hard Enduro, which seems to be popular everywhere. It's well known within the Hard Enduro scene that the riders who are at the pointy end of the field are mostly ex or current trials riders. We don't need to do any advertising to get these new people coming along to trials and having a ball.
Another story about people doing cross-training on trials bikes is about a middle-aged rider who had obviously done thousands of hours riding dirt bikes and had some amazing bike skills. However it was very entertaining when he had a go at riding trials sections on a borrowed bike and could not, no matter how hard he tried, stay within the boundary tapes.
Just thought of another story. This time about arbitrary rules in trials. One local rider convinced his Dad to have a go with him at trials and bought his Dad a trials bike. No matter what we said about the rules, the Dad would not, ever, inspect any sections from outside the section or by walking them. His idea of the right level of challenge was to ride through each section navigating only using the coloured arrows as he could see them while riding along through the section!
What other Yamaha dirt bike fork tubes (not stanchions) are identical to the TY250A? I was thinking 74'/75' DT250 might be the same?
I would like to replace one of my fork tubes and it might be easier to source other Yamaha dirt bike tubes.
Glenn
DT250 sliders of the same era will probably work apart from the lack of the mudguard mounts that make the TY250 sliders unique.
There are two different slider types on the TY250A. The earlier type has the drain screws on the sides and the later TY250A type has the drain screws at the rear of the sliders and are the same as the TY250 BCDE models fork sliders.
I'd be grateful for advice please on what pullers/special tools are needed to replace the crank seals on a 1978 Bultaco 199a.
Magneto side requires a puller for the magneto flywheel. The magneto flywheel will have ID on it so you will be able to buy the right puller.
The drive side seal requires you to take the clutch off and to get to the clutch nut, you may need a clutch spring tool if you have the spring pins that have a cross-pin retainer. If you have threaded clutch spring posts then you wont need any special tool to get to the clutch nut. The clutch nut is 22mm (from memory) and requires a thin-wall socket because the nut is recessed. I machined the OD of a standard 22mm socket down for this.
To unto the crankshaft drive sprocket nut it is helpful but not totally necessary to have a clutch holding tool. This sprocket is on a parallel shaft with key drive. It may need a puller to get it off. A standard industrial two leg or three leg puller will do for that. The clutch basket and crankshaft sprocket come off together with the primary chain in place.
Bultaco clutch holding tool (helpful if the motor is out of the bike)
Bultaco clutch spring tool (unlikely needed on a 199A)
I've been mulling over the comments from @lemur & @lineaway to figure how I might channel some of their attitude to riding events to my own.
I came to the thought that we are just fundamentally looking for different outcomes due to being at different places in our riding "careers".
You have both been riding for decades, with hundred of events behind you. Critically, I'll take a pretty confident guess that neither of you are on the steeply rising part of the skills acquisition curve, your peak was quite some time ago. This gives you quite a different set of goals. I'll hazard that you don't much see trials events as an opportunity to learn and improve, nor as an opportunity to identify skills and techniques to work on before the next event - very obvious when lineaway states he doesn't practice between events. My guess is going to events is sort of a comfortable, familiar activity that just gives you pleasure for the simple act of going riding and with like minded people. And whatever else tickles your fancy. I completely get that - in skiing I peaked in my early 30's, some few decades ago. Since then I've only been on the gradual decline of skills, so I have a far more relaxed attitude to the activity than I did in my 20's.
I'm not in the same place in my Trials journey. I'm still on the steep side of the learning curve, and loving that. I am driven to improve my skills for as long and as far as I can. As I said, I expect there will come a time when decreasing ability due to age effects intersects increasing skill due to practice, and that's as good as I'll ever get. Then I'll need to adopt a new mindset. But until then I just want to get better, learn to ride things I presently can't and generally feel progress. However alongside that I am not externally competitive - I don't care how I place compared to others, that's irrelevant to me. I only care that I am learning and competing against my previous self.
There will be a third group of people at events who are trying the improve just like me, but are also competing for the sake of competition. They want to move up the placings and grades. Perhaps they want to reach toward the pinnacle of the sport and ride Trial GP.
Then there'll be all sorts of other individual motivations, but I think these three groups probably pick up a majority of riders at comps in some shape or form. For instance the Enduro cross-over riders are probably more akin to my motivations than the other two, even though their ultimate goal might be competition driven in Enduro itself.
So while I can appreciate your approach to events, I'm not sure that it's entirely relevant to me at this stage of my journey. No doubt I can take some part of it and bring it to my own psyche, but fundamentally I go to events to learn and ultimately improve. If I come away feeling like there's been little opportunity to do that, then there's little motivation to return. I already try hard to take away from events some key areas to work on, whether that be coping with bigger, scary obstacles or being more accurate, or simply keeping a bit more flow in my riding.
This has made me wonder if there might be room for some adjustment in an event so that people like me could maybe start riding half an hour or an hour earlier, without observers and without score cards. Our first lap would be totally un-scored and pretty much do what you like. Then our remaining laps would be scored, but not included in results.
There's obviously a bunch of issues to solve, it wouldn't work for all events, but maybe one or two a year?
I feel like this would be a huge motivator for me to go. I could really work on some of the sections and obstacles that I can see are where my skills are lacking or where I'm just not confident. Then in the scored laps I would get to see how it all transferred to comp riding, and be able to just enjoy the comp without feeling like I want to stop and work on something.
Maybe tie it in with section setting - if you come and help set sections you can ride all of them before the event, but then not be included in results.
Just thinking out loud.
I do like how you think outside of the box. Please keep at it. Here is a story that might be of interest.
At 64 and with lots of old injuries, I'm not looking to take big risks when riding trials, but for the past 15 years or so have had a thing about improving the setup and performance of my twinshock bikes, mainly to maximise how long I can keep riding trials for, because I get such a kick out of riding trials.
Part of this bike improvement thing is that I have a few comp bikes and find that by riding the different bikes in the same sections on the same day, I can better work out how to improve them. Swapping bikes like this is usually detrimental to my score.
It's also great fun riding different bikes through the same sections.
It's not a big deal though and it wouldn't stop me from riding an event if I wasn't allowed to swap bikes. All I do is ask the event organiser in advance so I know how to approach the event. Sometimes it's no and sometimes it's yes. If they have concerns about fairness to other riders, I suggest that I'm happy to be taken out of the results if I swap bikes.
In your case, you may be able to choose events that are more favourable for the sort of riding you want to do. Many clubs I'm familiar with run events where you can continue riding the sections after the event and also, depending on the observer and if there is a queue or not, are happy for you to continue in a section after having fived.
This is very much just a personal observation, but I'd be interested to hear how it resonates with others.
The last "regular" trial I went to was a bit of an exercise in frustration - I was (knowingly) riding a grade at & above my abilities because I enjoy a challenge and I don't care about placings. I ride for self-satisfaction.
That 2-day event saw me really struggle in parts, taking voluntary 5's on a couple of sections. The second day I dropped down a grade which at least let me ride every section.
Last weekend I went to my first Gate Trial.
Lot's of fun - more fun than I think I've ever had at a comp.
Last lap I decided to go for maximum points (11) on every section. I ended the lap with 9 x 0 and 1 x 11, total of 11 out of possible 122. LOL. And had a blast. Totally different experience to getting 5's at the previous event.
Reflecting on the difference I realised a big part of it was that at the gate trial I could mostly ride at least the majority of the section even if it was going to end in a failure. There were only 30 or so riders, so no one was too stressed if I continued to finish the section after a dab (failure). There's also sometimes the ability to structure your ride so the hardest obstacle is later in the section.
In a regular trial once you 5 then you have to leave the section. If that hard obstacle is one of the first, then you'll never get to ride the rest of the section.
So now I'm seriously considering how interested I am in going to more than the odd Trial. I enjoy riding challenging obstacles, I enjoy riding terrain different from my home area, I enjoy riding what others have set. But I'm not interested in spending $100+ dollars and usually 6 hours driving time to go to an event where I only get to ride a percentage of the sections.
If the rules where modified so it was OK to complete the section after a failure, even with a very short time limit - say 30 seconds, then it might be different. At least then I'd get to challenge myself, and get to ride everything I can.
Of course the other option is to drop down a grade and change my idea of challenge to simply keeping my feet up and getting a much lower score. Strange idea I know.
I'm working on changing my mindset to emphasize low scoring on easier obstacles, but damn it, I enjoy having a crack at harder obstacles!
I guess it is largely the difference between comps as competition, and comps as practice. I go to comps to ride on something I can't at home, and to ride with others. The competition itself is a very distant third.
What do you think? Does it take away from the enjoyment when you have to ride conservatively in order to get to ride everything in the sections?
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.
Feet up fun, thank you for the response. I did not know the Michelins were tubeless, seems to me that’s going to present a problem, this Michelin set of tires is for a TY 175.
don’t know if I mentioned that my two TLs a 125 and a 150 both have Dunlops the 150 is a Mick Andrews School Boy framed Tall Boy? Frame swing arm and triple clamp on it. Haven’t ridden it yet it’s at Pete Fisher “ Power Roll” ex owners house his son Scotty’s doing the 150 upper install.
shhesh I did it again, my mind wonders while I’m writing stuff. Think it’s from being a retired cop. I’m so used to writing everything in a descriptive manner like a dam criminal report.
feetupfun if I may where are you located at? I’m in USA Oregon. Finding it fun to meet folks from other lands.
dirk
Hi Dirk I'm in Gladstone, Queensland, Australia. We have an active old trials bike scene and have a great time.
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.
Hello again, I have a Honda Matise MH200 it looks road ready to me has lights ,horn ,speedo, brake light. I have no documents ! How do I register it ??? All advise welcome . Regards Bernie.
I can advise you to say what country you want to register it in
Quick question regarding draining the oil after my water pump seal failed on my 2004 Gas Gas TXT Pro 125. I've replaced all the water pump components with a new kit (shaft seal, impeller, circlip etc) and wanted to ask about draining the sump. Obviously there was water ingress into the oil so my question is how do I go about ensuring I have gotten all the water out of the sump?
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.
Can folks give some input on the value of a 1973 montesa cota 247 trials bike? Looking at parting with my father's bike which is not currenlty running and we need a ballpark idea of what to list it for. Thank you in advance.
$AU500 to $AU3000 depending on condition and location
Interesting. I never knew Sherco and Scorpa were related. I knew about the Montesa, Honda thing because I owned an 02 Montesa. I remember the clutch cover ( I think) having an HRC emblem. That's a long time ago lol. But I remember that
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.
Has anyone taken a 125 out to a 175 or a similar size? Or what is the max you can out of the standard 125 barrel.
I was hoping to locate a 175 barrel and head, seems a fairly rare thing nowadays!
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'm not sure if I should try an IRC tire or maybe the tubliss system. Does anyone run Tubliss on a trials bike?
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.
Montesa 348 exhaust
in Montesa
Posted
I'm assuming you are asking why the mounting holes do not perfectly align with the muffler sitting there.
How close does it get to the mounting holes lining up if you lift the muffler?
If that's not enough, you could loosen the exhaust mounting bolt near the airbox and loosen the bolts at the cylinder and try moving the exhaust upwards.
If that's not enough you could bend the end section of the exhaust upwards.