stork955

Gday, press the old one off if you can. It removes almost any chance of damage. You can tell if the shaft comes out by looking for weld underneath. Few bikes are. I use the inner of the old bearing to press the shaft and new bearing back on (cut a slot in the side of the old one with a grinder to make it easier to get off afterwards), and the old cups to tap in the new cups. Most important is to pack them correctly - just wiping grease around the outside is not enough. You need to get a handfull of grease in your palm, and "wipe" the new bearing's edge into the grease which will push the grease into the cage and between the rollers. Keep going until you see grease coming out the other side, and turn the bearing a bit and repeat until you have it all the way around. I also like to pack a good dollop around the top of the lower bearing to help keep water out of it. Grease the cups and you are ready to go. Adjust them firm firstly with a spanner, and then back off till loose and retighten by hand until all freeplay is gone and no more. My Techno uses stock off-the-shelf tapered rollers which are the same as your I think, much cheaper from your local bearing supplier. Cheers, Stork

Gday, I agree higher bars are the answer. I run 6" Renthals on my Beta with an extra 30mm of spacers under to lift them up even more. The big guys don't use them because they are all 5'6 I guess:-) I'm 6'1 and find most bikes are "short" for me. Cheers, Stork

Gday, yes, that is the way you measure oil height -with the leg compressed fully. You also need to pump the leg a few times until the internals are bled out, you will notice the level dropping while you do this until it settles down, and then take your measurement. It may well pay to completely dismantle the legs so you can clean them properly. I believe the later bikes like yours use a cartridge type of damper and these typically get full of rubbish which can effect damping. A complete strip will let you clean and flush the internals properly with solvent (kerosene etc. )It also pays to lubricate all the adjusters with grease to prevent seizing later on. Don't for get to lube the fork seals with some grease also on re-assembly, then you have a clean slate to set oil levels and adjust damping settings etc. Cheers, Stork

Gday, Search around the Sherco forums for the fork seal job. They are the same pretty much. Good luck bleeding brakes - also search for that topic as you will probably need it. Cheers, Stork

Gday, clean the exhaust. There are many posts in the forums on how. That will make a big difference to the bike. Cheers, Stork

Gday, can you dig out the potting right back to the circuit board and solder a new wire in? It might be a bit of a job, but to save the cost of a new one might be worth it... Cheers, Stork

Gday, they probably dont think we want to play with our timing! - Its always been a bit neglected on bikes anyway. Most people go straight for the carb and possibly dont know how much is actually gained from timing adjustments... My TDC tool is made from an old plug (I have 3 in fact in different sizes)with the centre knocked out, and tapped for a bolt with a rounded end. Easy to make for anyone really. It gives a nice reference point so you can advance it up till it pings and back it off a couple of degrees. Cheers, Stork

Gday, I have seen an online tool on the net somewhere that calculates degrees to mm BTDC. You need to know the rod length IIRC and some other data but it would be workable. My Techno has a timing mark on the flywheel so it gives me a reference point to work from. The other way to do it is to use an advancing light and make your own TDC mark which is easy to do with a piston stopping tool. This is what I generally do especially when Im in a hurry on a paying job. 2/4 -As far as points go if you need to adjust them every 2 trials I have to ask are you lubricating the rubbing block? On the Hall sensor thing, the sensor itself isn't digital as I understand it. It does need a nominal current and allows an "external" current flow through itself when in the magnetic field. The sensors do have wave shaping built in to give a nice square wave result, which can then be used with either digital or anologue systems. It would work fine with your standard basic CDI however it still needs that constant 5 volts or whatever to run. The dual pickup system is as you say Cope, totally RPM based - it uses variations in sensor output voltages (Reluctors increase output with speed) to give a change in advance. The system (as I understand it) splits the output from the advanced trigger into 2 waves, one that is held constant, and the other that is allowed to change. The outputs of both are summed together to give a resulting change in retard amount. God only knows how this would happen with a Hall sensor... maybe someone can explain this for me! Cheers, Stork

Gday, try using ATF in the 'box. It might help, and its cheap compared to rebuilding if it works. I take it there are no weird noises, other issues etc associated with it? Cheers, Stork

Gday, just a quick thought regarding the carb, Are the ones on those Bulty's a bolt on flange type? If so, don't over tighten the nuts, its a classic way of making the slide stick. If they use a rubber, just ignore me... Cheers, Stork

Interesting - A Sherco system! It seems I'm learning a bit too! The stator wouldn't vary for single or dual maps as that is all done in the CDI. Grounding something is probably changing the way the wave shaping comparitor bit does its job to get the different curve. That stuff is getting over my head... Cheers, Stork.

Gday, That's the easy way to tell Jon, 3 wires for a Hall sensor. I was thinking this morning that another reason Hall sensors are not common in dirt bikes is because they need a stable supply voltage to run which is not easily obtained in your dirtbike. Unless it has a battery. Of course Honda have worked around that with the Montys, but I hazard a guess that they still use reluctors for triggering. And definately a hall sensor Cope! What was that system from? Cheers, Stork

Gday, some early Yamaha's (TT 350's and some others I think) used 2 triggers in their systems, the one closer to TDC is used when starting so your knee isn't driven into the bars when it kicks back and the other is the "advance" trigger. That is probably what Leonelli are doing. There is no need these days to use two triggers for different advance curves, even without a battery for a constant voltage source to run the electronics. I've never seen a Hall sensor on a dirt bike, they all use reluctors (factory systems at least) apart from the very early systems like the PE and RL suzuki and KDX's etc. They use a simple coil much like the source coil but with a lower output. Hall sensors take up too much space for the timing disc! (And they might not be as resistant to vibration etc as the reluctor). Cheers, Stork

Gday, the electronic ignitions use 2 coils - one makes the power to run the system, and the other smaller one "tells" the ignition to fire. Both of these coils are mounted on the stator plate, so if you move the stator you move the ignition timing. The pickup or trigger coil replaces the points but effectively works the same way and is what the CDI uses to "know" where the engine is. The modern things with 2 maps (sometimes more) vary the actual advance curve the system has built in, so one curve will use slightly less advance than the other. (Technically CDI's cannot "advance" - they actually retard from a maximum point back towards TDC). This is one major variation from points systems in that they actually have a variable timing system. As an example, one curve might give a maximum amount of 20 degrees and another might give 18. Of course its more than just that, but hopefully you get the idea. Retarding the timing will make the Techno more tractable, but go with the lower gearing as mentioned above. I have retarded my 270 a few degrees and it pulls like a tractor but is "soft" which with my riding skills is a definate bonus! Hope this makes sense, Cheers, Stork.

Gday, if it has a ball, the answers are no, and no. Cheers, Stork.

Gday, you have a common issue. You need to crack the throttle slightly while starting the bike in this condition. The reason is that after a short "soak" heat from the engine begins to evaporate fuel in the carb bowl, causing an over-rich mixture which sits there until it dissipates or you try to start the bike. Holding the throttle slightly open weakens this mixture slightly by allowing more air in, so restoring balance. Its the same as the hot start systems people buy for the 4 stroke moto crossers etc but you do it yourself for no money. The amount you need to open the throttle will vary but you will find this out through trial and error. About 5mm on the grip will be a good place to start. Cheers, Stork

Gday, failing that, have a look here - http://www.hpi.be/universalignition.htm They have a rotor "sizing" guide that you might be able to crossreference to your rotor and get a new one from something. Heaps of stuff in that site. Cheers, Stork

Gday all, the FCR on the previous page is a standard carb, not C.V. (The difference is when the slide is connected to the throttle itself, which the FCR has, CV's use manifold vacuum as described earlier). EFI is better than a carb as mixture control is more precise. Atomisation of the fuel mixture is still a problem as raw fuel does not burn until it is vaporised and as mentioned, EFI still sprays fuel droplets. This is also true of carbs and in fact carbs don't atomise as well as EFI injectors. Basically manufacturers try to get the drops as small as possible and this is easier with EFI. Fuel wash and oil dilution is the final outcome of all of this but again this has been an issue since day 1 of the internal combustion engine. Its much better these days as a result of using EFI. The other advantage of EFI is the fuel can be delivered to the precise location where it will do the most good -usually onto the head of the inlet valve where it cools the valve, helps atomisation and promotes combustion swirl. The downside of using a mechanical carb on bikes is that inevitably the needle and needle jet wear over time, causing a rich fuel mixture, as they physically touch each other each time there is an intake pulse. Given correct maintenance and no tinkering EFI will never do this. Cheers, Stork

Gday, do those bikes use a high pressure fuel filter? I would assume that they at least have a strainer over the fuel pickup. It'd be worth a look at those. If it has an inline filter, check it by blowing it out backwards (by mouth air pressure only) into a bottle so you can see what's in it. If it takes any effort to do this it needs a new one. Apart from that look very closely at all connectors for corrosion. Its rare but I have seen it happen before! It pays to use dielectric grease on them while they are apart to stop this in the future. Cheers, Stork

Gday, Id check in this order - Correct spark plug to the letter. Aircleaner - Clean? - don't over oil it! Carb - float level, jetting and wear on the needle and needle jet. The smallest amount of wear makes a huge difference. I don't know the specs for a Rev 3, someone will chime in here. Clean the exhaust. Do this anyway. You can check spark - the best way is to grab a spark checking tool from your local bike/automotive shop and it should easily jump a 6mm gap in air. Basically though if it has spark it should be OK. Cheers, Stork

Gday, 126cc per side of 10W/30 is recommended. I use ATF. Cheers, Stork

Gday, its unlikely thats the problem. Start with your air cleaner and go from there as Jon said above. Check carb related things first (after the air cleaner) and of course make sure you have the correct plug for your bike. Fresh fuel too. Cheers, Stork

Gday Wally, both forks will increase air pressure as they get hotter with use. It sounds like your front sag is better, but maybe a little high statically. That is not as important as feel however. Both ends of the bike should move pretty much together. It sounds to me that you need to play with the oil amount in both forks - the easiest way to do this is to use a syringe with a hose that you can calibrate the length and remove oil above a given height. These tools are available cheaply if you dont want to make one. Start from factory and vary from there. What the factory level is - ? I have no idea. Maybe someone will chime in with the spec. From there vary a few mm at a time, and remember that less oil = more springing, and more oil reduces springing. Have you experimented with the damper settings at extremes to get a feel for how it changes? That is also a good starting point and costs nothing. Finally, its best to only change one thing at a time so you can go back to where you started if you dont like the results. Use a note pad and work from there. Good luck, Cheers, Stork

Gday, 2.5 ohms sounds right for a source coil. Remember you are really checking the length of a strand of copper wire. Much higher and there is a break, any lower and there is a short circuit. Also make sure there is no circuit to ground, unless the coil grounds from one end, in which case you are doing that anyway. (Hope that makes sense :-) Cheers, Stork

Gday, a couple of thoughts in addition to all those above. Your .36 mfd capacitor (are you sure its mfd's not ufd's?) would be available from any electronics store - get as high a voltage one as you can (there are ones that are suitable for up to 600 v). You need an electrolytic type, but dont get a polarised version. The value is important so get as close as you can. Very cheap ($1.00) to try. Recheck your timing - were you checking in the correct direction of rotation? An easily made mistake that can put your timing out 20 degrees or more - enough to cause problems. Also try starting the bike with exhaust removed. If it runs it will be loud,but at least you will eliminate this as a possible source of your troubles. Costs nothing to try! Its important that you do one thing at a time so you know what is actually giving you trouble. If that doesnt work go back to your starting point before attempting something else. Cheers, Stork