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scifi

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Everything posted by scifi
 
 
  1. Hi Guys, The Haynes Manual for the TY range of bikes gives the details for the 175 Carbs as follows.... Mikuni VM22ss , Number 52561 , 22mm Choke size. Main Jet 240 , Air Jet 2.5 , Pilot Jet 25 , Needle Jet 0-0 , Needle 4L6 , Clip Position 4th from top. Pilot screw 1.5 turns out for an idle speed of 1100 rpm All the TYs I have looked at seem to be as above, but one seemed to run rich at full revs. The small O ring on the needle jet should be changed regularly, as they wear and let fuel pass. .
  2. Many years ago I had a Honda tl125, but the trials organisers were putting lots of long hill-climb sections in their trials, or bottomless mud sections. So I went for a Bultaco 350 to solve that problem. Nowadays sections are different, not so much mud about, mostly tight turns and medium sized steps. So I have found that a Yam TY175 is mostly Ok. It is certainly easier to start than a 300 Beta Evo, you just move the kickstart from top to bottom, which all adds to the enjoyment. .
  3. Don't think that by coming out of the EU we will be exempt from these rules, or that the ACU will come to the rescue. Our trials rules are governed by the FIM in Geneva, they set the international standards, including the tyre specification. This is to ensure that foreign riders are using the same equipment as us British riders. .edit... Found this on page 10... Enduro and Trials motorcycles used on the road included in the type approval structure (Enduro and Trials machines manufactured for use exclusively in competition remain exempt) .
  4. You could try to be a bit more agile on the bike... get animated... I have tried bouncing on the footpegs two or three times, this makes the front wheel move in six inch steps each time you load up the rear suspension. I don't know what it actually does, just that you are in balance two or three times, until the corner is completed.
  5. Hi Lineaway, these Beta Evos use hydraulic clutch (and brake) controls. I think there are 70% springs available, that we could mix and match to get the correct amount of pressure, have not got around to buying any yet. Dan Williams.. I did do the glue filing, and polishing of the tags and cage. I am a bit too old fashioned to do much clutch action in sections, I just let it out at the start card, and pull it in at the finish cards ! So in the lower gears the slipping is not so apparent. edit... Whilst looking for clutch springs I found this on the internet... http://betausa.com/sites/default/files/pdf/STT-2012-3-Evo 300 clutch set up.pdf .
  6. I tried the removal of two clutch springs, but I am sure that on very long uphill roads in top gear the clutch seems to slip. Anyone noticed this? Mostly after quarter mile or so. .
  7. I don't know why you want to use anything but the original footrests. Way back when, we all used to shorten our fixed footrests so that they cleared rocks easier, we soon got used to the shorter pegs. If the Kickstart clouts the footrest, a long scaffold tube and a big vice is all you nee to give your kickstart shaft what-ever bend you require for clearance.
  8. I think there are many different types of alloy used on motorcycles, I always used Brillo Pads on alloy mudguards, and 'sealed' the shine in with a rub over with a diesel soaked rag. I have had a sign made up from aircraft grade Duralumin, it has remained shiney for over 25 years without even cleaning. Some alloys, or Yamaha magnesium alloys, go dull after just a few weeks. Whatever alloy they are using on Indian Enfields, tarnish after a few months. Most early British engines (and pistons) were made of almost pure aluminium. .
  9. Think it all depends upon the miles you do... During TT week in the isle of Man, I did the Scarlet Point trial, which had us going through salt water rock pools and up craggy climbs. on my Honda TL125. The following day I went to Ramsey to see a race, and when that finished I rode up the mountain to get back to Douglas. The Bike slowed in 4th gear, so changed down to 3rd, and it still slowed, pulled the clutch in and the engine revved Ok. but the TL had stopped. Tried pushing it back and fro, it was stiff. Thought I had done the rear wheel bearings in , so looked closely and burnt my fingers on the chain ! It was near enough seized. Not having any chain lube on me, I used the next best thing, butter from my picnic pack in my rucksack. That got me back to Douglas, and then some borrowed engine oil got me on the Liverpool Ferry and back to North Wales. It's all good fun..! I was told by an elderly technician, who used to oil mechanisms with one drop of oil on a small paintbrush, that you only need oil on the bearing surfaces and that all the oil on the outside should be wiped off with a rag as it only attracts dust.
  10. Don't know what area you live in, but around here, the Manchester17 club does several 'Dead Easy' trials... And they really are dead easy, it is sometimes more difficult going between sections than the sections themselves. Its a good day out, and you are unlikely to end up in the local casualty department. As you gain skill you will find that your total score will be in single figures, and 0 is possible if you get it all just right (you could finish equal first with maybe ten others !) Some of the Classic Clubs allow new bikes to enter, and their sections are non too athletic ! I find it is much more pleasant to end an easy trial on 6 points than a very hard trial where you would loose over 80 points. You get to be able to figure out what went wrong, so much easier. . As for your bike stopping, where you running on Main or Reserve..?
  11. scifi

    BSA C15

    Used to have an ex works C15 that had a Scrambles frame and engine tuned for trials, for use in the SSDT. After I used it for club trials, I modified it further to be competitive in Scrambles and Grass Track. Used a 1 1/16 Amal on Methanol, sprint cam, Goldstar inlet valve and 12:1 CR Piston. The Close Ratio Gears cost just £15. So if you want to mod a road bike to trials, there are several things needed changing. Frame mods to give Ground Clearance at least 8 inches, High Lift Exhaust. Single Seat, Long Movement Forks, maybe modern shocks to extend the travel on the rear. Proper handlebars and ball end levers. Then the engine needs the correct low compression, and a mild Camshaft, there is also the Wide Ratio gears to find. I think these days you would need folding footrests. Lower gearing cogs gearbox / rear cog Then to use trials tyres, a 21inch front wheel WM1, and a WM3 18 inch rear wheel, with the security bolts. Best of luck I don't know if the frame head angle lugs were different types on all the BSAs models, maybe that's Ok.
  12. I have always thought that the softer the better for MX or Trials, to give you the best ride. The forks should bottom out at least once on every lap of a MX track or during trials sections, that is what bottom stops are there for.
  13. scifi

    TL125 Backfire

    A bit of spitting I can accept, but this little monster is refusing to jump, and throwing me over the handlebars !
  14. Haven't used my evo for some time now as I went to do a season of classic twin-shock riding. Mine is the opposite problem, the fan runs continuously, starts to turn as soon as the engine starts. Most likely the thermostat, but have not yet checked it with a multimeter.
  15. scifi

    TL125 Backfire

    Thanks for the reply, I set the ignition when I changed the cylinder, so have had a gauge down onto the piston to check for TDC. I did note that the screws on the points plate were very worn, as if the previous owner had been adjusting the timing many times. I tried it again tonight, and got some of the petrol on my fingers, it wreaked of turpentine, so maybe its gone stale, will empty the tank, and try fresh fuel tomorrow... fingers crossed.
  16. scifi

    Electronic ignition

    I've timed several engines, including 4 cylinder cars, and found it best to set it up by adjusting for best tick-over and slow running. If you have clean running then who cares what the actual degrees are? Could solve your splutters...
  17. scifi

    TL125 Backfire

    Bought a TL 125 with a 150 cylinder, and when I rode it towards a log and blipped the throttle, it would backfire and make the engine kick backwards. I got a 125 cylinder and the same problem occurs... sounds like... bup bup bup bup bang, with the instant stop. Twiddled everything on the carb, it must be some sort of pre-ignition.
 
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