feetupfun

What Billy says does make sense but why do you need a battery for the fan? It gets very hot here in OZ and we just leave the motor idling when inspecting sections so the fan runs when needed. Sometimes the motor runs for hours without stopping or problems during summertime (well over 100F) events.

More info needed Neutrals between which gears? Upshifting or downshifting? Does it happen when you shift with the motor stopped? Is the shifter moving back freely after you shift? Is the shifter moving all the way back to the mid position each time? Did it have the problem before the several years rest? Why do you think something is loose in the cases? I suggest you post questions about your 172 in the twinshock or mechanical help forums

No matter what frame you use for a TL250 engine, the height of that long stroke, wet sump motor will always create a centre of gravity/ground clearance compromise that handicaps the bike in comparison with others of that vintage. If you yearn for a Honda 4 stroke twinshock that is light and handles well, a far better better starting point is the humble TL125. With suitable engine work (bore and stroke increases), a different front end and rear suspension mods, these can be made into something that is a much better competition mount than something based on the TL250. Attached is a photo of a TL250 (Jeff Eckert, Queensland, Australia) showing an exhaust that lightens the TL250 without spoiling the beauty of the original styling.

From the wide range of lightening techniques you already mentioned for your TL250, it sounds like you already know what is needed to get the TL down to a nice weight so why are you asking for more ideas? If you did all those things to your TL250, would it really still be a TL250?

This is intended for Beta Rev3 owners. If it hasn't been done since the bike was new, you should: Dissassemble, clean and grease the steering head and swingarm bearings. Remove the shock mounting bolts, clean the bolts and holes and reassemble with antisieze including the OD of the head of the lower bolt. Remove the front vertical frame member screws and apply antisieze on their threads. Remove, antisieze and refit the handlebar cross brace screws. Periodically: Check the rear axle nut is tight. Check all the brake disc screws and sprocket bolts for tightness. About the air filter Replace it if it starts falling apart. Keep a new spare in a dark cool place (the fridge is good). Only clean the filter if it is dirty or the oil is getting dry or is contaminated with water. Air filters are damaged by UV light, heat, residual detergent, incorrect cleaning solvent and the mechanical effects of cleaning and reoiling.

Suggest you go back to whoever told you an RD400 piston will make a TY175 into 200cc and point out that the TY175 (66mm) has a larger bore than an RD400 (64mm) so it would be a small bore TY175 not a big bore. Yes a TY175 made 205cc goes great if done properly but it is not easy or cheap.

Those bars on Martin's 348 are beauties. Yes he is tall. As well as the high bars, the footpegs on his 348 have been lowered. The 348 second from the right has the original bars. I wish someone still made bars with a rise like those.

We finally managed to get these four Australian Cota 348s together and thought it would be nice to share the picture

Hello Cactus Jack. Where in the wide brown land are you?

The sleeve in my bike is made from an early 1980s Suzuki GS1000 sleeve and yes it ends up thin when bored to 72mm but is suitable to be bored to 72.5mm if required. The WR200/DT200 big bore pistons are no longer available here either. I would suggest checking out big-bore kits intended for the Yamaha Blaster Quad if you are serious about making your TY into a 205cc.

More snappy: lighten the flywheel More powerful: source a later model cylinder and head. The TY250B (1975 model 434), C and D model (493 model) TY250s are noticably more powerful than the TY250 (1974 model 434) in standard trim. More powerful: Big bore it to 320cc (DT360 piston, new sleeve, welding and machining). Not cheap but works More powerful: fit an ignition that has an advance curve More powerful: raise the compression ratio More powerful: fit an expansion chamber Talk to Bob Ginder at B&J Racing

Mine uses a piston made to increase the capacity of a DT200 or WR200 to 230cc. I've heard but not tried out a big-bore kit piston made by Wiseco for the Yamaha Blaster Quad. It's not listed in the regular Wiseco catalogue but are made for someone selling the kit for the Blaster. I've also heard that a TY250 piston can be used but this must also require a different conrod because the TY250 piston has a larger gudgeon pin than the TY175. KDX220 pistons are the right diameter but I haven't checked ring locating pin locations or pin to crown height on them. There is much more to it than finding a piston. The cylinder has to be resleeved with a larger diameter sleeve, machine the crankcases to suit the sleeve OD, weld the head and remachine to suit the new bore size and weld the cylinder stud holes up and redrill a smaller size. Shape the head to achieve the correct compression ratio. Find longer studs to reach through the head. Use plain nuts. Make a bigger head gasket. Lighten the piston as much as possible. Rebalance the crank, rod and piston to suit the inevitably heavier piston.

Best option is to get someone who owns a similar bike to listen and ride it. Next best is to make a video (with sound) and post it somewhere we can down load it from.

If you are running 428 chain on your TY175 then yes a 16 tooth front sprocket will fit. I used to run a 16 front 51 rear combo on mine when I rode it to work and it would do just under 100km/h on the freeway. Pretty useless on hillclimbs though.

For a standard bore size TY175: Thin head gasket Boyesen reeds Reed case spacer WES two piece exhaust A big bore (205cc) also improves things over standard but if you are going that far with motor mods I wouldn't lighten the flywheel until you are finished.

Dear oceanvibe In the last 10 years I have sourced many parts for Yamaha TY175, TY250, Kawasaki KT250, Montesa 348, OSSA MAR, Bultaco M49 and M198. I've had no experience with bikes that became popular after 1978 like SWM, Fantic and Italjet. Bultaco parts are generally the most abundant but other popular 1970s trials bikes also have their parts suppliers in different parts of the world. There are good suppliers for Montesa parts in the UK and the USA and the same goes for OSSA. Very few genuine parts are available for the Japanese bikes but there are very good reproduction parts available. If you buy a bike that is complete, you can be sure to be able to get it up to competition standard. If it is a popular model, missing parts can usually be sourced from wreckers and on eBay. My advice is to steer clear of buying any model that was rare in its prime, no matter how cheap it seems, unless you thrive on a challenge.

The steering stem is intended to shear before the forks or frame get bent. Instead of forking out big $$$ for new frame or new fork tubes, the steering stem is relatively cheap and easy to replace. Yes making a steel one would probably stop it shearing in a similar crash but if you want a trials bike to weigh 65kg, easily damaged chassis parts are part of the deal. Alternatively the same part could be made from titanium at huge expense but who would want to pay megabucks for a trials bike that was slightly more crashproof?

If you are ever unsure, drain and refill. Level too high or too low in service is bad news.

Hi Mike If your vice is too small, a large G clamp and two blocks of 75 x 50 timber about 250 long usually works for me. David

Yes it certainly is possible to fit the rear wheel from a M137/138 Alpina (or from a left shifting Frontera or Pursang) to achieve a brake drum on the right hand side. The penalty paid for this arrangement is a rear wheel that is heavier than the original M199A wheel because of the different hub design. You may find the rim is a bit wider than the Sherpa rim too depending on which donor bike it came from. Steel LH shifters are easily available.

Dear Austini I didn't need a lobotomy, being born here in OZ. I have found though that the heat does tend to gradually melt ones brain which is probably a bit similar to having a lobotomy, but slower. Anyway, about the fasteners, I have seen two Beta Rev3s, one TY250Z and one Scorpa SY250 all suffer from the frame screws and brake disc screws coming loose in use. I don't think it is a problem confined to SY250s. David

Don't ask me why it works but it does. Instead of loctite on these threads, use a thread antisieze compound.

Hi James I suggest you might get more response if you post your 349 queries in the twinshock forum. I would say it is very likely that the 248 front end would fit your 349 provided you use an axle length and wheel that matches the width of the fork tube spacing of whatever clamps you use. David

Mich Lin Are you having a bit of a lend here? Do you really carry a handgun when out riding? Where I ride we have snakes that leave anything in the "Wild West" of the USA far behind for danger to humans (Australian taipans, eastern browns, and tiger snakes in particular are quite deadly while death adders provide a similar risk of death from a bite to the US rattlesnake) yet all most people do is keep their eyes open. People who like to take precautions carry constricting bandages and some form of hand held communications. Please tell me the snake shot gun thing is really a joke.

2001 Rev 3 270 should have come from Beta with a hydraulic clutch. Betas have had hydraulic clutches standard in all Rev 3 and also the preceeding series which came out first in 1994 (Beta Techno). Are you able to post or email a photo of the bike you are looking to buy?