phiggs

When I was a youngster, I used to deliver newspapers on my push-bike, at each stop I would lay the bike onto the ground before stepping off the pedals. As my paper round was quite long I used this technique many time a day. I could also step onto the pedal and lift the bike, to continue on my way. So theoretically you should be able to lay your trials bike all the way to the ground and back up, without dismounting... It's worth a try... hi hi

Sometimes increasing the power to the back wheel is counter productive, especially in muddy conditions. Learn to use the clutch by slow riding ( or static.), practice starts in a straight line, and also whilst cornering in tight spaces. Remember, lowering the gearing effectively gives you one more lower gear ratio, but some sections require 2nd, or 3rd or more.

I don't think you will need to change the pilot jet as the slow mixture screw can be varied for best tick-over. The main jet should be chosen for best performance, and plug colour. I see you might have some difficulty finding a long enough piece of land to hold it at max speed for a few miles however. Richer is probably best, so that it four strokes at max revs in the garage, much the same as setting the high end mixture screw on chainsaws. Also bear in mind you might want to ride in the mountains at some time..!

Yes.

That wing nut on the additional side panel looks to be an accident waiting to happen...

Way back in time when trials could be up to 40 miles in length, we used 32:1 ordinary oil. On the long inter-section road links, the exhaust would finally heat up and cause a pretty good smoke screen behind you at full throttle in top gear. . . . Once the trial was over there was still the 25 mile ride home on the bike. Modern sections are hardly 100 yards apart, so different rules apply.

A kitchen knife would work OK, if you can sneak one out of the kitchen. To resurface the valve you grind a new surface into it at the correct angle, usually 45 deg. There are many Heath Robinson ways of doing it, if you don't have the correct machine. Don't forget to lap the new surface into the valve seat with grinding paste, for an air-tight seal.

Well 50:1 is about normal, but some use 70:1 if using fully synthetic oil.

If you have a track stand, or suitable blocks of wood, chock your bike up vertically, then stand on the pegs. You should be able to stand with your hands not applying much pressure at all. This goes for the fore and aft position of the bars as well as the height of them. Also try left to right turns, is the forward bar end going beyond your reach..? Hope you get it sorted to your position.

Over 80% of the hassle with trials riding is the preparation: Club membership, ACU License, Helmet suitability, Boots suitable and Dubbined. Transport to the trial. Bike preparation and spare Petrol. Entry on time... etc etc. Once you have all that done the riding is relatively easy. On hot days, an energy drink is advisable, or flask of hot tea... Have fun.

A lot depends on how long you run the engine. Some trials bikes just run 20 seconds in a section, then cool down in the 10 minutes waiting for the next section. Enduro bikes, or some moto-cross, run for up to an hour of full throttle action. I hope the NGK BR6ES works for you... ( Other brands of spark plug are available.)

As for the second way, to just wheelie for a hundred yards or so. It is easy on a MX bike, as they have sufficient power in 2nd 3rd and 4th, maybe 5th, in a six speed model. You only need to be in a sufficiently high gear to be able to throw it down the track, on the rear wheel. Just opening the throttle with a slight pull on the bars, to get the bars at chest level. Trials bikes are easy to wheelie on slightly uphill ground. it's not often you need to wheelie downhill, unless you need to clear an obstacle. As for clearing obstacles, I seldom use the clutch, unless it is from a standstill.

I ran a Bultaco 350 for many years and got away with the perforated mesh between the bottom two frame rails. If you make any wider bash plate you are opening up yourself to loss of control when bumping over rocks or tree trunks. My Ossa Mar is very wide at the sump, and it threw me off once when trying to balance on a not too flat rock. . . . Stick to the mesh, and straighten it every so often.

Hi Guys, I have just replaced an old wheel on one of my bikes with a brand new one, as the old one was going rusty on the rim and spokes. Would there be any problem with painting the new wheel with Clear Coat Spray, so that it would last longer (over 30 years) than the previous wheel..? I have used this petrol proof spray on freshly painted fuel tanks, and it has given good results. .

Sound like your coil is either dirty, wet or cracked. If the spark is going to the outside of the coil, instead of the plug, then your engine must be running very strangely if at all. A new coil would fix the problem, but you could try drying the old one in a hot place for a few hours/days.

Well guys you may have noticed that we have a Global Pandemic affecting all our lives just now. I am a member of several bike clubs, but as they hold their meetings in Public Houses, this has not been possible for the last 18 months. No Beer = No Trials. Fortunately some events are coming back, especially the ones where social distancing is possible. i.e. Solo ride-outs to certain landmarks etc. ( got to do Joderal Bank next week.) Three of my local clubs have just held their first meetings, but limited in numbers. So I didn't go, as I left my space for the Committee Members to have their say. I hope you have all kept your ACU Licenses current, as events are happening to return.

Must admit I have never seen that done before, but it seems like a very good idea. Might try to get our club to allow that, cos it would be good to try some of the easier expert bits, once in a while. .

Just found this on the internet, as a guide to re-jetting for changes in altitude and temperature. FAQ REJETTING FOR ELEVATION AND TEMPERATURE CHANGE (jetsrus.com) One carb manufacturer recommends -5% in jet size for every 3000 ft additional height. .

Some exhausts have a hole in a low part to drain any water that condenses, so don't worry about it. The carb screw only adjusts the slow running mixture, so not too likely to cause a black plug. It is more likely main jet or needle position, but first check the air-filter, as a blocked one will richen everything up.

Hi Guys, I used to have an old two stroke motorcycle with a 225 single cylinder twin exhaust engine. It had a 6 inch lever on the side of the points backing plate, that could be used to vary the timing. The engine would run with this lever either vertically up, all the way to about 90deg horizontal. So Ignition timing was not so critical. Admittedly there was one best position, that you could find when driving down the road, but that was +- 10 degrees before you could notice anything. The starting position was best set a little retarded, if you didn't want a kick-back. . . . So Guys, it's not so critical that you get it to less than 1 degree. Having the points surfaces polished smooth is much more necessary.

I think it has something to do with there being a breather hole in the float chamber, which lets neat fuel into the engine, when the angle of the carb is tilted forwards. Maybe this could be modified, or blocked up, but the float chamber still needs to be ventilated somehow.

I had a similar problem with my ride-on mower, it would run for some time Ok, but then went all weak at the knees. It turned out to be a blocked fuel tank exit hole, which needed three blasts with an air compressor to clean the debris out of the pipe. You might have the same problem, best of luck..

The orange wire at the end of that semi-circular valley looks to have been rubbed by the flywheel, and possibly shorting out. .

Looks like a nice carb, I haven't got any of those on my relics. The old Monoblock was notorious for having a rich incident, on most scrambles bikes way back then. The only cure was to lay the bike on the ground whilst it sorted out the mixture. Happened to at least two bikes every Scrambles meeting. .

If it was changed deliberately, it could be for several reasons. Maybe he ran with more oil in the fuel, and needed a hotter plug to keep it clean. It could be his choice of Winter plug vs Summer plug, especially if he only ran the engine for three or four minutes at a time in the sections, rather than flat out for hours on end. I wouldn't think a change of just one grade would make too much difference, are the colours on the electrodes looking Ok..? .