stork955

Gday, drain all your fuel and put some fresh premix in. It sounds like the carb needs a clean, I dont think you have an ignition problem if you get the occasional "chuff" from it. Check the plug - use a 21 mm or 13/16 spanner to undo it. Its easier if you pop the wires off the fan temp switch to do this. My Techno likes full choke to cold start (no throttle) and turn it back off after a couple of seconds and let it warm up. Make sure the rear brake has clearance between the pushrod and m/cylinder piston - search other threads, there is heaps in here on that topic. Let us know how you get on. Cheers, Stork

Gday, was that a dip type hot tank or one of the dishwasher styled ones? Cheers, Stork

Gday, ditto to all above, and it might pay to check the float drop while you are in there. I'm sure you'll find the method for doing this on the net. It basically checks that the float drops enough to allow fuel into the bowl as the level gets lower. There is an adjustment on the side of the float arm for this. Cheers, Stork

Gday, if you have a local engine reconditioning place, get them to put it in their hot tank( parts cleaner) - it'll remove the carbon and paint and leave everything else. My local blokes do this for nothing for me. Cheers, Stork

Gday, Dry, Black and Sooty plug = Too Rich (too much fuel). Check the Air cleaner first, then make sure the carb is set correctly and it pays to make sure all the exhaust is clean too. Cheers, Stork

Gday, the parts cross reference I have only shows TY 250 T/S as using these forks. Go the rechrome, it works well and good TY forks are pretty much impossible to find. I have 3 sets in my shed that are currently useless! HTH Cheers, Stork

Gday Spoke, stick with what is specified originally for your plug cap - the system is designed to work reliably with this in mind. More volts wont make the bike go any better but it can damage the CDI or break down insulation in the ignition coil causing failures here. In almost every case what the manufacturer did originally is best for the bike. Resistor plug caps are most commonly used on virtually everything today so they should be cheap and easy to get if you need to replace it. A good tip here is to put a squirt of dielectric grease onto the end of the lead from the coil to help stop water getting into the screw connection and causing corrosion problems which can haunt you down the track. Cheers, Stork

G'day, you have found your problem, the source coil is shorted internally. This coil provides all the power for the ignition system. It typically makes about 50 volts AC at kickover, rising to 100 + volts AC running. If it is weak in its output the whole system falls down. It typically fails through vibration and heat. Sometimes weak magnets in the flywheels can also cause a low output here as well, but your issue is the coil itself. The resistance measurement effectively checks the length of the coil and if it is low it means that the coil is touching itself (no pun intended...) somewhere inside and bypassing some of the windings resulting in a low output. The actual wire is just copper wire coated in a varnish to act as insulation and this is what has actually broken down. The only cure is a rewind or replacement. It would pay to check if your bike is meant to have a resistor plug cap also, many early CDI bikes never used one and this can also cause issues with the CDI if incorrectly fitted. 5K is a typical plug cap resistance. HTH, Cheers, Stork

Nice! Stork

Gday, probably not enough oil. 6.5 inches down sounds like a big air space - do you have an actual specification for the bike? ( I assume that this measurement is done without the spring and with the fork fully compressed) ATF is actually around 7 weight anyway so that wont be the issue. A big air space above the oil is like a second spring - the air itself, being compressable, acts like a spring. The most important thing if adding more oil, is that you don't overfill which will cause hydraulic lock when the fork is fully compressed. See if you can find a spec, that will sort this question out. HTH, Cheers, Stork

That oil looks OK. IS the cooling system still full? That's the best way to tell for minor loss. Keep in mind that with no expansion bottle the coolant will sit a few mm down the filler neck when cold to allow for expansion when hot. Regarding the petrol thing, the petrol is not the problem, its the vapour left behind - think hand grenade when hot... Like I said, that oil looks OK. It will be like cream if there is water or "Silver Flecks" if there is metal. HTH Cheers, Stork

Gday, All Balls (available anywhere) list 4 seals for 35x47 forks - 33-129-44 = 35x47x10.5 33-129-72 = 35x47x10 33-129-83 = 35x47x7.5/10 33-129-67 = 35x47x7/9 The -44's (10.5mm) are fitted to heaps of Euro bikes from the mid 70's like Husky' and Ducati which sounds right to me if they are Betors. Also, make sure there are no mark or nicks in the tubes, anything at all will only cut the seals apart and continue leaking. Basic rule of thumb is if you can feel a mark with your finger nail it is no good. HTH, Cheers, Stork

Gday, if you can feel the scratches in the shaft with a fingernail It'll need a new one. It looks like the seal is shagged (there is a rust mark on it) so you should replace the bearings as a precautionary measure as they have been washed out by coolant. Its better to do this now than have to pull it all apart later to do the same job. The bearings locate the impeller anyway so if it has been touching the case that's probably why. I don't reckon you need to do anything with the case and impeller but its hard to tell from the photo's. HTH, Cheers, Stork

I wear Knee and Elbow protectors as well as helmet, gloves and boots. They get used a bit with my skill level... Cheers, Stork

G'day, Bore size is the diameter of the cylinder, and no, I have no idea how to check side clearance on tapered rings. I haven't even seen any for years so its lucky that fact was pointed out. A bit of research in my trusty ACL Rings book calls them Trapezoidal or Keystone rings and reveals this - Keystone and trapezoidal rings are sometimes used in engines with chromium plated bores. Always check that any chromium plated ring does not go into a chromium plated bore. Note also that tapered side rings will appear to have too much side clearance when fitted to the groove. The correct position to check for side clearance is when the ring outer face is flush with the land. In this position the ring must still have side clearance. Note: Some tapered side rings have a bevel on the outer edge to neutralise any twisting which might otherwise cause high blowby. These rings will still have the dimple the dimple or letters to designate top. I probably knew all that when I was at tech,so long ago now... Trapezoidal rings have only the upper face tapered, Keystone are tapered on both the top and the bottom. The book says that side clearance should not exceed 3 thou with the face flush with the piston. I also forgot to mention back clearance - making sure the ring goes right into the groove in the piston. There is a spec, but usually I just make sure I can push the ring below the face of the piston. HTH Cheers, Stork

Gday, I dunno for sure on the Sherco, but most fans will cut in at around 90 degrees C (195 F). Your cooling system is pressurised to increase the boiling point to above 100 C so there is no need to cool with the fan before this. That is where your thermo switch should trip. The engine is designed to run its cooling system around this temp so don't worry. You can get those stick-on things or use a thermometer to check the temp of the radiator if you wish for peace of mind. Cheers, Stork

Gday Neo, rule-of-thumb is 4 thou per inch of bore size (0.1 mm per 25 mm - a 75 mm bore should have around 0.3 mm gap). A little bit too much is better than too little. Also make sure the ring is square in the bore for checking - I do this at the base (unworn) end of the pot and use the piston to gently set the ring square in the bore. Keep the gap out of the ports. Also check ring side clearance (up-and-down) in the ring groove - about 8 thou (0.2mm) is getting too big. Obviously make sure the ring groove is clean first. Problems here mean a new piston. Cheers, Stork

Gday, its something that technically should be done on a regular basis, say every couple of years for our bikes. Same with cleaning the rest of the exhaust system. How old is your beast? Gasser mufflers can be repacked, I've done a couple, you need to drill out the pop rivets to get them apart, clean and repack and re - rivet back together. Pop rivets and tool available from any hardware shop. Packing from any bike shop. Cheers, Stork

Shaft measures 14.7 mm. Its a fairly fine spline - keep in mind that its "left-handed" and splines can vary. Good luck. HTH Cheers, Stork

Gday, I reckon you are on to it there. The slide is definitely knackered, but the big issue is the needle. The polished end is a dead giveaway, and likely the needle jet is worn oval. You can check this by finding a drill bit just a bit smaller than the hole the needle fits through and slipping it into the jet. Have a good look, maybe with a magnifying glass and you may well see an oval hole in the fore and aft direction. Carbs need only the very slightest amount of wear to alter the mixture radically, this is common on road bikes with a bit of work under their belts, some more than others. Replace the pair first before altering anything else (I reckon the slide also, it wont make it run rich but it can make it stick) and see how it goes. It would pay to check float needle while you are there and set float levels as well. Cheers, Stork

Gday Neo, mains would be shielded, not sealed if specified sealed. Sealed ones wouldn't last in the heat. I think there was some talk of this somewhere else in the forums. For crank seals go with the Sherco parts, often crank seals are a special and that's the best way to ensure you don't have to redo the job later. The bearings will have a number on them along the lines of this - 6204 C3 - which you can match at your bearing shop. The first number (4 digits) is the bearing size and the C# is the fit, make sure this is the same. Most Crank bearings are C3, but this can vary. Otherwise you can match dimensions, most (but not all) bearings are commonly sized. Honda are good at making unusually sized ones... If you get stuck measure them (ID, OD and width) and I'll look them up in my bearing book for you. Important thing is to fit the bearings and seals carefully and square in the bores. It pays to send your missus out for the afternoon and use the oven to heat the cases. Be prepared to be in trouble when she gets home and can small the results... Heat them to about 100C and your bearings should drop in. Let them cool and use a good-fitting socket or similar to carefully drive the seals in. Make sure they face the correct direction - have a good look at the ones coming out to get this. Lubricate them with a smear of grease before putting the crank in! Make sure also that all gasket surfaces are scrupulously clean as well. A kitchen scourer works well for this and wont damage the gasket faces. Use those green scotch pads from the supermarket (not the steel ones!) After all that, don't force anything - if things wont fit, stop and have a look what's going on before resorting to the big hammer... HTH Cheers, Stork

Gday, I can measure mine for you if you like. Why do you need this if I might ask? Cheers, Stork

Gday Neo, some clutches have a shock absorber built in, I dunno about the Sherco (A lot of dirt bikes don't bother) but that may be what you are seeing there with your free play. The rings each have a locating pin to stop them rotating into the ports. Be careful with these, make sure the gaps are lined up with the pin. Some need to be fitted the right way up also (the pin is mounted at the top or the bottom of the groove) One of the knowledgeable Sherco guys will let you know if its an issue for your bike I'm sure. Cheers, Stork PS -did you get your piston and barrel measured? They don't need to be scored to be worn past limits.

Copemech writes- ::::::::::::::::::::::::::::::::::::::: Storks other point in relation to the car. Well, if you just started it up and went from section to section while shutting down and restarting every time, it would likely fowl plugs too! Fuel or oil would make little difference here if you never really got out and drove the friggin car! As these things require a bit of normal running and cleaning out from time to time. Seems some negate that fact and just putt about, shut down, putt, shut putt,shut! If you never evem attempt to see if your bike will even achieve maximum RPM, then it may well not when you need it most! Blow some soot out of it! This is basic plug maintenance! ::::::::::::::::::::::::::::::::::::::: (Sorry I couldn't work out the quote box thingy) Good point! Stop/Start and cold running is an issue with our bikes. We see the big boys "cleaning" their 2 stroke bikes out on the DVD's all the time, and I do it myself. Not that it helps me ride any better... It is natural for 2 strokes to carbon up as they constantly burn their own oil so that can help things, give it a good ride to get it hot and a blast and see what happens afterwards. It might just stop any issues experienced. Certainly I have no trouble with any of my bikes. Cheers, Stork

Gday, is that carb the original one for the bike? Cheers Stork