scifi

Back in the day, when we used steel ball end levers, I noticed that they were not all to the same design. Some had the nipple to pivot distance of 1 inch, but I had some that were 3/4 and some even less. So you could try a lever with a smaller pivot distance, to give you a lighter clutch. Also the cables are nearly always nylon lined these days, so that could reduce the friction even more. .

The welded up hole was most likely caused by the clutch basket finger exiting the chain-case. As there are many ears on the friction plates, I don't suppose the loss of one will be noticed. The irregularity might actually help to avoid the plates sticking together. The only downside is that the clutch may now be out of balance, but as it revolves 3 times slower than the engine, it might not be noticeable. Hope you manage to get a replacement from someone who has parts for TYs.

You want the Falcon 'Speed Bump Shocks'... With their 5 inches of movement, they will coast over 4 inch Speed Bumps, without you ever feeling a thing... Just 400 Dollars from your local supplier...

If your studs have a coarse and fine pitch, the fine pitch nut end should undo before the coarse pitch. On old British engine studs, the coarse pitch was BSW and the fine was BSF, mostly used in cast iron parts without lubrication or Loc-tite. .

I am sorry to hear about your injuries, hope they get better with time. As trials require full lock to lock movements with the handlebars, will this be Ok with your restricted arm movement..? On a road bike you only need to move the bars an inch or so in fast bends, but trials requires the full lock quite often. There are a few venues (e.g. in N Wales.) where the course in-between sections can also be a challenge, think of slippery muddy 100 yard climbs etc. Will you be Ok if you need to get off and push..? Also most courses are 4 laps of 10 sections nowadays. Ask locally if there are any simple events to attend.. I hope it works out for you.. .

Just noticed something else that will prevent a wheelie... You ought to try 2nd or 3rd gear, not 1st. The camera's wide angle view makes it look as if you are going faster than you really are. I can generally get my 175 up to my ears, and straight back down in less than 8 feet, in 2nd gear. .

I suppose you do realise that it is possible to buy a brand new 36a Villiers engine, and fit it into a square section frame that you have recently built, and call it a classic bike. I have yet to see any vintage Scott, Rover or Sunbeam motor cycles, but maybe I just go to all the wrong meetings. .

Quote... Rule of thumb :- any modifications I make are ok, anything that goes one step further is cheating. Showing my age a bit, but I remember a time when if you raised the ground-clearance, it was frowned upon. It should be worth stating in the rules that a seat of 1 inch or more thickness is required... But who needs more rules... .

Yes it is number 4, but it is a very odd size, not often found in O Ring Kits. ( from memory maybe 4 x 1.5..?) To tell if the O ring is worn, it should be a squeeze to put the float bowl on. If the float bowl just drops off the o ring, then it is too slack. You can use a smear of silicon grease to lubricate the fit. .

Have you checked the ignition timing...? If it is retarded, then the response could be slow. Also if the points gap is on the small side, it will retard the ignition. The TY175 has Contact Breaker gap = 0.35 mm (0.014 in.) and Piston BTDC 1.80mm (0.070 in.) I suspect the 250 is similar.

I think the current is much less than 0.5A , cos if you work out the power ( VxI=W.) you would get 50,000 x 0.5 = 25 kilowatts... Nothing on the bike, including the engine produces that amount of power. I think the current will be much smaller, maybe micro amps, or milli amps at the most. There were 5, 000 ohm resistors that you could insert into the plug leads, which would reduce radio interference, yet do very little in reducing the voltage. Your plug lead needs a much higher insulation to avoid the current leaking to ground, or to your fingers.

Why do you want longer Stantions and Springs, are you thinking it will give you more travel...? ( cos it won't.) The travel distance is set in the slider, being the distance between the bump-stop and the upper bearings. Maybe you just want to convert your bike to an Easy Rider type Chopper..?

You need tyres with less grip, have you tried Mitas..?

Looks like it will do the job, as long as you don't want to win any International Competitions. My MAR has a similar paint scheme, but does have 5 gears. I find the crankcase is quite wide, so for some rocky trials I ride my Yam TY175.

Sound like it is running too rich at full throttle. You haven't done something daft like clean the main jet out with a twist drill have you? Or perhaps you have put the needle back in the wrong notch. Either way you should have a sooty plug, to confirm it is running rich. Maybe the cure is to reduce the main jet size until it gives the correct performance. edit.... Just had another thought... Is the Cold-Start mechanism working correctly, with no rotting of the rubber seals.?

Hi Lefebvre, your idea about the seat/fuel tank is good if you intend to ride for many miles at a time. Most Trials riders change their rear tyre before it wears more than 2mm, but for Trail riding you can ride them down to 1/4 tread depth and still have lots of grip on forest roads. Also the tyre pressures should go up from 6+4 F+R, to 12 all round for road work. You may find that the trials gearing is quite low for fast road work, so you could try a larger gearbox sprocket, up from 12t to 15t would get you moving a bit quicker. Have fun...

Well you ain't going to make one of those, unless you have a 200 ton stamp press and the correct dies. So you will need to fabricate it out of 6-8mm sheet steel, and machine the angled curve to match the frame. Then how to provide the screwed portion is up to you. The standard exhaust does attach via a twin rubber bushed Dog-Bone, but I have seen many different types used, some with and some without the rubber inserts. The Dog-Bone piece is 28mm centre to centre (others are up to 40mm.) and hangs down at whatever angle is required to fit. .

10 psi..? Are you riding an Enduro or MX Bike..? The standard setting for all trials bikes is about 6 psi front and 4 psi rear. (as 99% of all UK trials riders will tell you.) As for damping, when I rode Moto-Cross, I used to have very minimal damping both front and rear. The idea was that the suspension had to recover quickly between bumps, especially when taken at racing speed. However for trials, where there is usually 3 seconds between each bump, the damping can be a lot slower, try sae15 instead of sae 5 oil. It's not all about rider comfort but about keeping in control. .

Same here….. 404.That’s an error. The requested URL was not found on this server. That’s all we know. .

Have you tried riding down the steps..? On the 1 it will be Ok, but on the 2, 3, and 4 you will need to aviate the front wheel, and land first on the rear wheel. The reason for this will become clear to you if you manually push the bike over the 3 logs... As the front wheel hits the ground, it will try to go on to full lock, and unless you are a Yorkshire-man you will not have the strength to stop it...!

Hi, remember there are two separate end floats in the little end, and each needs to be independent of the other... 1. The needle roller cage needs to be free within the little end, as the cage needs to move ( it rocks at half the speed of the rollers.) In the above photo, it's 19.5mm within the 20mm eye, = 0.5mm slack. 2. Then the little end eye and spacers need some slack on the piston gudgeon pin, maybe 1 or 2 mm, but this might be specified somewhere. .

You say you have tested it on a stand, does this mean you have not tried riding it...? Maybe your bite point is out of adjustment... Have you re-assembled the push rods and mushroom correctly...? Aren't two of the plates thicker, and need to be put on the outer and inner of the clutch pack... You did put the springs back in..??? .

You could check the heat range of the plug, to see if it is the correct one. Or maybe even try one grade hotter plug. Trials bikes take a bit of a battering as they very rarely run under power for more than a minute or so before you are queueing for the next section, and never get to run flat out for an hour or so, like road bikes. As long as the plug does not foul up and stop working, you should have nothing to worry about. .

Some bikes ( in 1970's grass-track ) were required to have no tick-over at all, so needed the throttle stop screw to be well unscrewed. (I am not too sure of the current ACU regulations.) So you could try that to see if the engine goes to idle sooner. For Trials you can set whatever tick-over speed you require, some riders even adjust it for particular sections. Get to see what is the correct method of setting your tick-over mixture and speed. It is usual to adjust the mixture screw for a peak in revs, then back off the throttle stop screw to reduce the revs to whatever you require... I usually err 1/8 turn on the rich side of peak, to avoid a lean cut when accelerating. .

Hi Brian, I know nothing about the Canadian Trials scene, but best of luck, and hope you find the organised events near you. The 300 may just suit you, but just because you have one bike, does not stop you from getting a few more... ;)) We are lucky here in North Wales, just this week there were 3 events within 40 miles of home, and lots of the easy sections that I now prefer. .