feetupfun

Sorry Woody I had the metallic green paint matched by a spraypainter from an old KT sidecover. I suspect that is the sort of thing that most people have done. The spraypainter told me there were no listings (or he didn't have access to any listings) of paint numbers for old dirt bikes like the KT. David

Tim that got me thinking and the first famous/infamous person with Wayne as a middle name I thought of was John Wayne Bobbit.

Woody the late 1970s KX125 case in the photo I posted has the arm at the top of the clutch bulge like the red KT photo and the 250cc KT prototype shown in the Don Smith book. Every KX250 I have seen has the arm at the front of the bulge. How can you say the KX125 cover is the same as the KX250?

Heres a KX125 with a clutch cover that looks like it might be the same

The red KT in the photo has a KT motor that has been fitted with the clutch cover from a KX motor. Why don't you take a photo of your motor and post it up so we can have a look at it?

Ignition timing is adjusted by rotating the stator mounting plate. Yes you have to take the flywheel off to get to it. Your motor probably has adjusting slots for the screws that hold the stator mounting plate to the crankcase. If you rotate the stator mounting plate in the same direction as the crankshaft rotates, you will be retarding the ignition ie it will spark later in the cycle than before you moved it. If you rotate the stator mounting plate in the opposite direction to the way the crankshaft rotates, you will be advancing the ignition ie it will spark earlier in the cycle than before you moved it. I hope this helps

We run 10 club trials per year and rider numbers have increased from about 20 (total) in 1995 to 60 (total) at present. This year the numbers riding at events has ranged from 25 to 45. Most riders live within a 150km radius of the riding sites. Some drive 1800km (1080 miles) each way to attend the 2 day events but that is only two or three of the riders and they only come twice per year. Most of our riders live in one of two regional centres separated by approx 120km, both around 50,000 population. One is heavily industrial, the other heavily agricultural (beef cattle). The industrial centre tends to have more riders per unit of population (probably due to a high proportion of petrol heads) Successful strategies for us are: Running all-day riding demonstrations at weekend markets, swap meets, machinery shows, car shows and annual regional shows. We have a permanent riding display site at the Historical Village of one of the towns and a portable set of obstacles including fake boulders, real logs and a creek with waterfalls (made of fibreglass). Getting a story with a photo in the local papers during the week preceeding the trial Making posters and having then displayed at motorcycle shops Inviting the local TV station to come and take footage - they usually stay for the first lap and put 30 seconds coverage on the local evening news. Running a club email list for everyone who shows an interest in trials Running a club website with lots of interesting photos (not just top riders on obstacles - lots of people shots) Supporting the use of older bikes (for people on tight budgets) with donations of parts and help with keeping them running Keeping as many second hand bikes in the local area as possible. This has worked very well with the growth we have seen because new riders can buy a 2-3 year old bike without having to travel long distances to a capital city. Having an annual final 2 day trial/Christmas party with a catered meal and award presentations One of the riders produces an annual DVD of the years events with very high production values and this is first shown at the party. The contributing footage is communal. I just converted our local "gas" price into US units and it is $US6.87 per US gallon. The people who drive from 1800km away pay more like $US8.00 per US gallon on most of their trip.

I just had a read of the New England rulebook and while there are some differences to how we run things, I couldn't see anything that would be affecting rider numbers.

Heres the Aussie version. Click on General Competition Rules 2008 http://www.ma.org.au/Content/MA/FormsRules...f_motorcycl.htm

If you like hopping the front of the Scorpa, why not just learn to hop the DRZ instead of all that modification stuff? I've done lots of course setting for Pony Express and Enduro events on a similar bike to your DRZ and found that when you get caught in a very tight spot the old fashioned balance-the-bike-on-the-rear-wheel-and-pivot-it-around-to-the-new-direction works very well. It is easiest if you pivot towards the left so you can hold the rear brake on while your left foot stays on the ground.

Copemech's explanation is very good and even works without a beer to help. The man in the boat is definitely what makes the boat.. er...bike turn. That is why bikes are more fun than 4 wheelers in my opinion. There is way more skill needed to do the turns well on two wheels. Whoever it was that asked the question first, you can do an interesting experiment on a dusty surface that will answer your question perfectly - actually any surface that will leave a visible track of the front wheel of your trials bike. Part 1 Ride the bike in a full lock turn with standard fork height. Measure the diameter of the front wheel mark. Part 2 Raise the forks as high as you want in the clamps and try it again. Again measure the diameter of the wheel mark (it might be a bit smaller diameter than part 1) Part 3 Put the forks back to standard position and ride the turn with the bike leaning over into the turn about 30 degrees and your inside foot just above the inside footpeg (to make sure you have all your weight on the outside footpeg). This time the turn diameter will be much smaller than in parts 1 and 2 and you may not have even touched the steering angle stops in the process. Good clutch control, rear brake control and footpeg weighting is how to make a trials bike turn amazingly tight. If you ever find the front wheel sliding sideways on a flat or soft surface, that is a clear message that rider technique is in need of improvement.

Its not Don Smith that created that ugly KT frame, it is just a standard Japanese feature to have an ugly frame. No matter what Don created in the UK for Kawasaki, by the time it became a production bike out of Japan the elegance would have been lost. The Cota 247 frame design (created by Don Smith and Montesa) is pure elegance.

Well you might have slightly reduced the pressure drop through the airbox, but the reduced surface area of the air filter media would surely cause a few issues if the bike ever gets ridden in dusty conditions.

Yes that would be great. I would love to be able to do away with having a side stand.

Yes Neo. Of course that can be welded back up again. If you have to pay someone tradesmans rates to do it though it might cost you more than a new set of pegs. You really should think about getting some decent strong pegs though and improve your bikes reliability. Imagine if that had happened during a trial. Forged steel, pressed steel, fabricated steel, cast steel or titanium (for the weight conscious) footpegs are the go unless you are never going to scrape or whack them on rocks. Hebo pegs are almost indestructible and very comfortable.

Blocked or almost blocked fuel tank vent

I was in the same boat as you a couple of years ago. There is probably no need to modify the bike, just keep practising and the sensitivity of the controls will miraculously become exactly right as your brain adjusts. Be patient. It will happen. Yes, a slow action throttle tube can help you adjust. You will find that modern clutches are absolutely fabulous to use once you get used to them. Same for brakes and throttle too. I don't get what you are saying about the clutch lever. You should be able to use one (usually the index) finger with the standard lever and rotate the bar clamp wherever you want.

Dave, there are a few different pistons you can use. The cylinder spacer is to compensate for the different gudgeon pit height of the new piston compared with the TY175 piston (the top surface of the new piston must be at the same height at TDC and BDC as the old piston) A popular choice is to use a TY250 twinshock piston. Another you can use is the KDX220 piston. Another is from a Yamaha Blaster (I think) quadbike. The TY250 piston has a bigger diameter gudgeon pin so would need the pin holes sleeved down. Can't remember about the other pistons re pin diameter. The cylinder will need to be resleeved. The crankcases will need to be machined out to fit the new sleeve OD. I don't know what other people do with the head but mine was machined to suit the new bore diameter. A much easier route for better TY175 trials performance is to take a bit of weight off the flywheel and fit a very thin head gasket. Top end performance can be improved with a bigger carby but at the expense of some low RPM throttle response.

About how the water gets in there- There are many possible routes for water to get inside the crankcase of a Sherco two stroke. You have checked for water leaking from the coolant circuit so scratch that. You don't often wash your bike (me neither) so scratch that. Water can condense out of the air if the inside of the engine is cooler than the dewpoint of the air. Depending on daily temperature swings and the amount of water in the air, it is possible (and in some places very common) for liquid water to build up inside things like fuel tanks and engines. It is why steel fuel tanks rust out so quickly. Water is also a significant component of the products of combustion in petrol engines so no matter how warm your motor gets, when you turn it off, some of the water which is in the form of a gas in the combustion chamber will turn to liquid water as the motor cools down. Being a two stroke, the combustion chamber is usually open to the crankcase with the motor stopped so it gets water in there too. About the oil- Yes mineral based two stroke oil will protect the bearings from rust better than synthetic oil when stored but if you are riding your bike every two weeks it is probably not necessary nor advisible. It would be the sort of thing to do if you were storing the bike for months in a wet climate. Using semi-synthetic oil can be a good compromise for preventing corrosion and minimising engine wear. Thats what I use too. Something else to think about- I hope you are totally sure that the bearings are failing due to corrosion. There is another possible mode of failure that is common in 1970s Bultaco motors that sounds like corrosion failure with the motor running, but when you have a look at the bearings, there are thousands of impressions in the bearing running surfaces caused by tiny particles of hard carbon being squashed between the rolling and fixed elements. Bultaco motors are more susceptible to that mode of failure than many others due to a couple of factors. One is that due to the design, there is no through-flow of fuel-air mixture to keep them cool and clean. Most other bikes have a hole ventilating the space between the bearings and the seal which provides a cooling flow. The other relevant Bultaco design feature is that there can be significant side loading on the main bearing races due to all four bearing seatings having an interference fit. Some people fit a roller bearing on one side to avoid this problem. Its a hunch, but maybe Shercos also suffer from this carbon particle induced damage. If the reason for the short life of your mains is this, then you should use the highest quality full synthetic oil you can get, at the mixing ratio recommended by Sherco, to minimise carbon formation. Using sealed bearings would also provide protection of the surfaces from carbon particles, but you would want to be sure that the grease inside was suitable for the duty.

After-ride easy-to-do sequence to minimise risk of rusty mains: Wash bike Fit a clean and freshly oiled air filter element Run motor enough to warm it up and to blow any free water out the exhaust Pull the starting knob to get it running very rich just before you turn the motor off Plug the exhaust For extreme protection: Before storing, run the bike on 20:1 premix using mineral based two stroke oil and petrol with no ethanol. Store it somewhere with a low relative humidity and minimal daily temperature swings.

Neo I'm with your wife on this one. I've been camping and bushwalking up the top end in summer and it is not the time and place to go trials riding. People are flat out staying conscious just walking slowly in the shade and it only gets slightly cooler at night. David

Chris Maybe the number is actually B440483 and the stamping of the second number was a bit poorly done in which case it would be an Explorer (and the frame will look very much like an MAR). A decent set of photos would be helpful for identifying your bike. I suggest you include photos showing the front mount for the rear mudguard, the wheel rims, the fork sliders and a close-up side view of the swingarm. Regards David

Synthetic oil has a higher film strength than mineral oil at the same temperature so it can generally be used at a lower ratio for the same protection. Synthetic oil creates less visible smoke if used at the same ratio. Using synthetic oil means it will take longer to clog up the exhaust pipe with gunk and form carbon deposits in the exhaust port and inside the head and on the piston crown. An air cooled motor sees a very wide operating temperature range which puts it more at risk of lubrication film failure than a liquid cooled motor. Synthetic two-stroke oil resists film failure due to high temperature better than a mineral oil will. It's not all good though. A fully synthetic oil is not as good at protecting the engine internals (conrod bearings in particular) from corrosion when it is not being ridden. My bikes sometimes don't get a run for months at a time so to provide good corrosion protection I use a semi-synthetic two-stroke oil. I live in a very hot climate and sometimes have problems with motors overheating during the extremes of use (my Cota 348 in particular is prone to heat related problems) so tend to mix my fuel for air cooled two-strokes on the conservative side at 3%. If I lived somewhere cool where motors have an easier life, I would probably use a lower ratio like 2% in my air cooled motors.

Here is a picture of the diode used on Yamaha twinshocks to prevent the motor getting a spark when rotating backwards. This diode is from a 1977 TY250D

Yes 25% oil is too much. It should run fine if you use somewhere between 33:1 (3%) and 50:1 (2%), full synthetic or semi-synthetic. Ideally you should not use two different oils together so either continue to use what is in it already or drain the fuel tank and carby first if using a different oil.