trialsnutterman

I guess it will be the inline one way valve on the tank breather, I've seen loads of bikes do this. The ball inside them gets forced closed somehow then the tank pressurises due to the heat and your bike runs rubbish as it's getting force feed fuel. Either remove the one way valve or drill a tiny hole in the plastic ball to stop it sealing closed.

I believe they are banned

Just try adjusting it. You will soon feel the difference. Usually it will be clockwise for more damping.

It is hard but it could be ground out or I bet there is some chemical that will dissolve it away but leave the aluminium intact, I've got a feeling the replaters have to remove some (if not all) of the coating before they replate. The new Gasgas 225 is just a cut down 250 barrel on a 125 bottom end.

Make sure the rings aren't tapered before checking side clearance. The 290 rings are definitely tapered so you can't check them as the gap depends on how far in the rings are. Stork955 do you know any way of checking side play with tapered rings?

They are nicasil lined, well some kind of coating anyway. I wouldn't have thought that would matter the biggest problem will be if the ports are the correct size and shape, there is defiantly enough material there, the 125 barrels are very thick and surprisingly heavy too.

either igniting it too early and hence it's getting hot due to the extra work the engine has to do to overcome the early pressure wave while the piston is still on it's way up. or ignition it too late, I've read before if it is back off too much the mixture is still burning as it enters the exhaust so the exhaust gets very hot.

Your crazy Leave them open, it will let some oil get down to the seals to help lubricate them. Oh and the (250 290) original bearings are 6206 Deep Groove Ball Bearing 30x62x16mm 2RS1 Sheet steel reinforced contact seal of acrylonitrile-butadiene rubber (NBR) on both sides of the bearing E Reinforced ball set TN9 Injection moulded snap-type cage of glass fibre reinforced polyamide 66, ball centred C4 Radial internal clearance greater than C3 GJN Grease with polyurea thickener of consistency 2 to the NLGI Scale for temperature range

Err the new sealed Sherco Main bearings are rubber sealed!!!!!! Beta use shielded mains SKF 6206 2RS1 E TN9 and some more digits specifying the clearance and the grease fill type, I'll get them tomorrow if I remember. You can get info on the designation suffixes here

Get your stator checked It sounds like the timing is out to me I heard of a few bikes that ran really hot and the cure was a new stator

Your cylinder head looks fairly normal, it definitely doesn't look like it has been running hot. Have a look under the piston is it black, this is a good tell tale sign the engine is running hot. What gets hot? Why do you think it is too hot?

I wouldn't ride mine without one, they are that good! I don't really agree with the comment that it losses low end grunt, in theory it should but in practise I think it gains low end as well, just because you can get it to run so much cleaner, the D shape slide is claimed to help the throttle response and I agree. As the Keihin runs so clean it feels a lot smoother off the bottom end making it easier to ride if you can handle the power!

It would be a all right starting point but you will probably have to lean them off. As your using a smaller diameter carb, the air will flow at a higher velocity causing more suction on the jets so it will probably run rich. Oh and could you edit the spelling of title to Keihin so people can search for this thread easier in the future.

http://www.malcolmrathmellsport.com/Sherco2009Academy.htm Pictures at the bottom of the page (.pdf)

I don't believe they are out yet well not for the public anyway. Some of the pros are using them, I know Browny has got a few sets.

This one maybe http://www.trialscentral.com/forums/index....showtopic=23386

Could be one of two things 1 The motor is cold so it is still running a little lean. 2 A build up of fuel in the crankcases so it runs rich when you rev it, maybe from using the choke. Both are normal behaviour, you should always take your time to warm your bike (and yourself) up properly, ride the bike around though just taking it easy.

We bought a similar product technoweld it looked brilliant in the demonstration but in reality it's a lot harder to get good results than was made out, I certainly wouldn't even try and weld a exhaust up with it, find a good experienced TIG welder, I got my exhaust welded up for about

Get some Gaernes! You can come and try mine on if you want.

Yeah it will help to some extent, the more preload you run the less sag you will have to unweight and therefore it should be slightly easier to hop. You will if it hard work staying on line riding along any rough ground though. Get practising more it will come eventually, it's all about timing.

Are you allowed to use titanium over there then? Just thinking I now seen 2 fires started from titanium sparking.

Reducing the port sizes helps with low end grunt as does lowering the ports so they don't open for as long. Also longer strokes are better for low end power. Motorcross bikes use power valves which basically close off the top part of the exhaust port for low end power and open up at higher revs to give a better top end. A lot of two stroke tuning is archived though tuned pipes, you may be best looking in to this for better gains. For example trials bikes nearly all use a fairly straight constant cross sectional pipes, where as motorcross bikes have a pipe which gets larger and then smaller before it enters the tail pipe. The length to the belly part of the pipe determines the engine speed at which it will improve power, short = high revs, long = low revs. The angle at which the pipe tapers determines the rev range at which the pipe will have a effect, steep angle = small range (hard hitting short lived power band i.e. road drag racing), shallow angle = large range (soft broad power band but less ultimate power i.e. a enduro bike)

If you have got a small crack in the radiator, it will certainly cause problems with over heating. The coolant system is pressurised to raise the boiling temperature of the coolant, so if you've got a crack you may find that the coolant is boiling on the cylinder head and around the cylinder walls, once you get air bubbles forming on the surface it will dramatically reduce the heat transfer. Air is quite a good insulator compared with coolant. Take your radiator to a local fab shop they will have a dye penetration detection kit and they will be able to weld the crack up, if they are any good. I'd also check your timing with stobe light just to make sure.

Well you have to pre mix your oil with your petrol to lubricate the engine, I'm guessing/hoping you already know this. There is no separate engine oil supply. I use recommend Ipone strawberry two stroke oil. Gearbox oil, you need to remove the bottom engine screw next to the sump plate near the gear lever there should be a sticker saying oil or something next to it. Refill from the other side of the bike through the larger aluminium screw after you've put the drain screw back in of coarse, fill with 450cc of gearbox oil, I use recommend Ipone Box 2. The Clutch is lubricated by the gearbox oil, it is a hydraulic clutch though so you can change the hydraulic oil I use recommend Ipone dot 4 brake oil. Check out these Sherco Manuals they explain thing with pictures making it much easier to understand, have a look at "Sherco Setup and Lubrication Guide" for changing the gearbox oil and "Brake & clutch system bleeding manual" for changing the hydraulic oils.

Do you really need the back light, I'd just take it off! If you really want it, I think there were 3 wires on that bike two switched power wires (one for the brake light and one for the main light) and a common earth, test to see which wire is the earth, I think this one goes in the middle but I am guessing as it has been a while since I took one off, anyway the lights are LEDs so you could check, diodes will only let power through in one direction. Thinking about the light will either work if you've got it right or not work if you've got it wrong, it shouldn't sort anything. I'll have a look tomorrow to see if I've still got a old harness that I took off, I can tell you for certain then.