feetupfun

I think all Yamaha PW50s had the same cap design. Another option even cheaper is to get an aftermarket (Chinese) PW50 cap. I bought one of those at a Yamaha shop for my 1983 Yamaha PW50 and it was under $10.

Neo I wish people spelled coarse and dual correctly but its not likely to happen anytime soon

Two answers Some people do make their own scale model trials bikes from scratch. There are some particularly well done Sherpa T models that have their photos on the web. There were at least two brands of plastic scale model kits for the TY175 made in the 1970s and 1980s and some of those kits are still available new-in-box. I found one in a hobby shop in NSW, Austraila (by searching on eBay) to give out as a rider award a couple of years ago.

Twinshock, air-cooled monoshock or water-cooled monoshock TY250?

A 200 Beta is probably the same weight or even slightly heavier than your Sherco. A Beta 200 is not a zappy bike and would haul you fine, as mine did and I am 51 years old and well over 13 stone.

If the problem was the perforated exhaust tube being displaced sideways then yes there would be an effect on how smooth it runs, but I would be surprised if it could cause pre-ignition. You said that you had a new ignition and had tried different settings, but have you checked what the timing is doing at different RPMs with a strobe?

Alan there is a steel sleeve that rotates inside plastic bushes. The bolt you are trying to move siezes inside the steel sleeve. The recommended way to get the swingarm out is to cut through the bolt with a hacksaw (bike upside down, swingarm rotated out of the way and something to hold the frame away from the swingarm enough to get the blade in). The sleeve comes out easily once the swingarm is free of the frame. That bolt freezing in place is a very common problem with TY250s and TY175s.

The standard Ty80 shocks have very soft springs so if they are not moving with an adult on the bike then one or both are probably bent or seized. Standard TY80 shocks are not meant to be rebuildable. If you can free them up they may be OK for a youngster even with no damping. Our TY80 has the original standard TY80 shocks with zero damping effect but they move freely and seem to work well with my kids (35kg and 22kg) riding it.

Whether your shocks are worth rebuilding or not depends on what shocks they are and you don't seem to have included that info in your posting.

I will bet that it didn't run with a plain big end for long

Neo it is quite frustrating to try and help people with bike problems over the internet with such limited imfomation. I will try and answer your questions: Adjusting the idle mixture screw may or may not noticably change the severity of a flat spot caused by too small a pilot jet or a part-blocked pilot jet. I'm sure I already said that it is not just the temperature of the air and the fuel that matters but also the humidity and barometric pressure. A flat spot caused by a carburetion issue is not usually revs, load or gear related. It is usually throttle position related. How about humouring me by either fitting the standard pilot jet or testing it out something like this: Stick some paper masking tape to the inner end of your twistgrip and another piece to the housing. Make a mark on each so that they line up just as the slide starts to lift off the stop. Warm your bike up fully and ride your bike in 4th gear along a flat smooth surface like a road. Hold your ground speed with the rear brake while moving the twistgrip from fully closed throttle to about 1/3 throttle, moving the throttle slowly in both directions. If you do this and still can't feel a flat spot, then there probably isn't a flat spot and we can go back to square one. There are other possibilities for the symptoms you have described but they are very unlikely compared with the possibility of a part-blocked or undersized pilot jet.

Maybe someone else will give an opinion that you can agree with

Neo you have gone too lean on the pilot jet. It was probably marginal until the weather went very cold. Cold air is denser and makes the bike run leaner. The fuel is also probably being affected by low temperatures and is harder to ignite (narrower flammability range). What seems to you to be the motor being more responsive is just that you now have a flat spot where the pilot jet has the most effect (just off closed throttle). You are actually moving the throttle through the flat spot/dead bit and when you go far enough open with the throttle, the mixture becomes strong enough to support combustion, and the motor takes off suddenly. To maintain a perfect state of tune with a carburettor equipped motor requires consideration of the temperature, humidity, barometric pressure and any changes in fuel type, oil type, oil ratio and fuel age.

I'm guessing you don't have Hyundai vans in the UK but the iLoad has taken off here like wildfire with tradies, delivery drivers and private users too. It is a recent and modern-looking design, is good to drive, good value, good on juice and if it is like previous Hyundais (imported since about 1984 here) will be good in the reliability and durability stakes too. iLoad has only been on the market two years so far. Hiace and Vito are the main models losing sales to the iLoad here. http://www.hyundai.com.au/iLoad/default.as...%20iLoad%202010

I'm with the poms on this one (colonial from the other side of the Pacific Ocean)

Issue 1 The airbox prevents water/mud impinging directly on the filter media. If liquid water touches foam filter media, it will wet the foam, increasing the pressure drop across the filter. When the airflow rate through the filter media gets high enough, the liquid water will be drawn through. It may travel harmlessly through the motor, or it may cause problems by bridging the sparkplug gap, getting into the float bowl, or if enough gets into the motor in a short time, it may cause great mechanical damage to the motor by preventing the piston from going past top dead centre. Issue 2 A pod fitted directly to the carby inlet (ie close to where the air goes into the carby) on a two stroke with piston skirt controlled inlet timing will become soaked with petrol, causing problems. This issue is not relevant to TYs as they have reed induction, greatly reducing the reverse pulse through the carby. Issue 3 Some bikes like the TYs have the carby supported by the connectors/hoses. If you don't have the airbox hose holding the carby up, and make the carby even heavier by fitting a pod, the connector between the carby and the cylinder will be overloaded on landings.

That cable is from an Italian aftermarket cable kit. I can't remember the brand - AGV maybe? The rubber concertina boot is from a TY Yamaha cable so no wonder it looks Japanese.

Thankyou. I'll stick with the roll pins

Thankyou Greeves That was fantastic to watch

Our 2007 OSET 16 24V has seen a bit of use now and has had a few electrical component issues along the way, but has been quite sturdy mechanically until the drive pin for the motor sprocket sheared recently. My 21kg son was riding in a manner I consider quite normal at the time, practicing crossing timber railway sleepers on a gentle uphill slope. I know it is quite a simple job to replace the drive pin, but am wondering if it is a common failure or not, to help me decide whether I should use a different type of drive pin or the same again. The drive pin that it came with from new is a 3mm diameter steel roll pin.

OK this is my M49 that has been modified by threading a hole in the cable stopper and using an adjuster on the cable outer. There is also a little hole in the brake arm for a split pin used as a security device to prevent the cable end coming off the arm (required to meet safety specs in our trials competitions)

Ha, I thought you might say that. I actually could get a photo of my M49 front brake real easy because that end of the bike is sticking out, but was taken aback when I went and looked at it - I had forgotten that I had done the mod DabDab talked about on my M49. I didn't want to confuse things with a photo of something non-original so didn't take a photo. Maybe it would be OK though because mr MCman56 might be interested in what a modded one looks like. Yes - in about 6 hours a photo will be up here.

And here is my TY250A motor showing the hole/plug that searay is talking about

I've gotta go and have a look at mine the suspense is killing me Ok here is what a LH case from a TY250D looks like.

Dave the cable on the mcman56 Sherpa T runs down the rear of the fork slider so it is nothing like your later model set-up that runs down the front of the slider. I'm think your M49 cable runs down the back of the slider. David