Mech

Ok. I just found one for 2001-20014.. but I'll get the one you have, and have a look.. horrible complicated wiring these yamahas have.. I bet it has about nine wires into the cdi.. at least !! And too many complicated isolation relays.. I'm drinking beer now though, so don't expect any sense out of me(yeah right) before tomorrow morning..

There's probably a gear position sensor down on the side of the gearbox.. You could try to locate that and check it seems to be working. A lot of bikes will start in gear if you put the brakes on enough to light the stop light.. Try that.. You might have a flat battery too or a bad starter cable by the sound of that dimming dash. If the dash dims when you push the start button then it looks like a bad battery or cable.

I see there are two manuals here, up to 2000 and from 2000 onwards.. Are you using one of those two ? Which one and I'll download it and have a look at the diagram..

The figures for the coil are way off though.. it needs a new coil.. Do that first and then start testing..

"If I leave it sit for a few weeks I do get a weak spark for about 10 cranks and then nothing."... CDI ? Flakes of metal on stator/trigger poles ? I think I agree with Savage, you need to check there is AC voltage coming out of the stator windings (the three with the very low ohms, approx 1 ohm) and the trigger coil (high ohm reading, approx 80 to 200 ohms). If there is voltage coming out of them, then trace the wires and make sure that at least two of them go to the cdi unit. Check they are getting the same voltage at the cdi as they were down at the engine/stator. Check the stator and the trigger coils windings and wires to the cdi. Let us know what AC voltages you were getting. If at least two of the stator's three wires (not counting the trigger coils wires), aren't going to the cdi, let us know.. it means it's a 12 volt cdi.

The wrong coils ? CDI systems have to have a coil made for them, not one made for the old 12 volt systems. A bad earth or, if it has two wires, reverse connected.. Bad mounting, either distorting it, overheating it, or vibrating it too much.. All long shots because they are normally pretty tough.

I'd look up the year 2000 onwards and see if the parts looked different, then try to decide which is my model.... Or look up your bike on another site and see if they recommend those parts, which are listed down the page further i see.

Mmmm.. Well the service manual says to check those pins for power and earth and the gauge should go.. Better check the power/earth is getting right in, not just to the end of the wire.. crimped connectors can get dirty on the wire.

No worries Dwayne.. Just thought it might be a help..

"I'm also a bit confused by the DC and AC on same wire. CDI is fed AC. ".. I figure that is probably right Savage.. an AC voltage of about double the DC voltage, and I'm guessing one half of the wave is being sunk through a diode into the capacitor.. that could explain that. The DC will be pulsing I figure. And yes, as Gw says, some pictures or even better a diagram of which wires go where would be helpful.. You could trace them with your multimeter if it has a buzzer or using the ohm gauge. It would be good to see the wires with their colours at the engine/stator connector, the crank position wires with their colours, and the wires at the cdi unit with their colours and the wires and colours at the kill and possibly the key switch.. And also if you can find an earth, what colour they are using for earth would help.

Coils for cdi bikes are pretty much universal.. You'll get one that will do the job no trouble.. Just find one the right mount spacing, with convenient terminals, and a long enough HT wire. I don't think we should even try to guess the correct readings or the wiring for the cdi unit.. Without a service manuals it's better to verify everything else is working and so through a process of elimination deduce whether the cdi unit if good or not. That's how it's generally done even with things with a service manual available. One thing you can do is eliminate wiring as being the problem.. Trace the wires from down on the stator connector on the engine, up to the cdi unit, and check all of the wires have the same resistance/ohm reading up there as they did have down at the engine, or check for resistance from one end of those wires to the other..

The stator and trigger coil readings sound about right. The ignition coil isn't right. The primary winding should have almost no resistance, a half an ohm perhaps, and the secondary winding should have a high resistance.. I don't know what the readings should be on the cdi but the service manual will tell you. They vary a lot. Without a manual I'd change the coil and hope that's the only problem.

There's likely one on this site..

If you look up the parts diagram online it will probably help, and if you download a service manual and have a look they generally tell you early into it what can be done on the motor and gearbox without removing the motor.. and what needs the motor removal. If you copied the parts diagram and marked it where you reckon the leak is it might help too..

I don't have one or know much about any of them in particular, but I know that you can do quite a bit of diagnostics using the service manual and the dashboard display on most of them. The engine anyway is fairly well supported.. the EPS maybe not so much.

The way you describe it as chugging to a stop makes me think you should check for fuel in the oil.. when it's cold and before you start it check the level hasn't/isn't going up, and take the oil fill cap off and smell for fuel. That does happen. Other than that you should check the state of tune, how the spark plug is, replace it if necessary, adjust the valves, adjust the idle mixture and speed.. That might cure it and is the recommended starting point.. Then, if you bought a cheap timing light it would tell you if the spark was dying out after fifteen minutes if you still had the problem.. Or.. To eliminate the electronic part, any way you could borrow a buddiy's cdi unit, or that would be ok with you trying your's on his bike to see if it changed things.

"Is the 15 minutes at idle or normal driving? ". Good question Curmudgeon.. If it definitely seem like it's more a matter of time rather than load or temperature, then it could be electronic.. If it just takes a bit of time(long enough to clean out the airbox), then starts again for a few more minutes, and it's sort of consistent, that really sounds like electronic. If you have a timing light put it on and watch it when the bike starts to falter.. See if the spark is giving up..

First thing I'd do is recheck all my work taking the starter out, looking for knocked off wires anywhere near where I was working, or bad or wrongly connected wires, or bad earths between motor, frame and battery. Then, as suggested, disconnect the kill switch, check the spark plug, check the spark plug.s cap for resistance or shorts to earth, then start checking the coil, stator and trigger coil.. If all those seemed to be ok I think I'd pull the stator cover off and check for tiny bits of magnetic stuff stuck to the magnets or trigger or stator winding laminated cores.

To adjust the slide needle you take the top cover off, pull the slide up, take the needle out taking careful note of where the spacers above and below the C clip go(look carefully, they are different thickness), Then shift the C clip up or down to another groove in the needle. Putting the clip higher makes it leaner.

Try these guys.. They used to have an amazing range of old OEM parts... https://www.anacondaltd.co.nz/

The high speed mixture is changed by moving the slide needle or changing jets. There will be an idle mixture adjustment somewhere though, perhaps underneath at the front/engine side and facing downwards. Aftermarket carbies often need some adjusting to get them to run right.

Yeah well I'm a mechanic and I manage to overhaul things for an economical price for people.. My customers don't think it's a waste.. I don't like the idea of scrapping things just to go buy a new one..

The gearboxes are simple too.. Most manufacturers design their gearboxes these days so it's almost impossible to get them wrong. All specialists tell people that they need their help, and that there are dangers involved, and that paying more and getting them to double up on things is the premium way of doing it.. There is a lot of bullshit and pandering to people's vanity involved in a lot of it... I've seen it and been inside it.. It's why I became self employed.. I always advocate that people should have a go at fixing things themselves. I've always been willing and happy to give my time to anyone that wanted to have a go themselves. In the mechanical field, there's nothing that somebody else can do that we can't do with training and care.

Wheels hit solid things all the time.. I think Vince is having you on. If a gear broke and the gearbox locked up maybe.. but a wheel.. Pffff.. Anyway, when I was young and not very careful I put a crank together and didn't align it carefully enough... you know what happened.. It vibrated for about three seconds then started to get smoother and smoother.. My sons have done the same.. After a few revs they are as good as gold.. and go for years.. Weird aye ? But then I wouldn't have been building race engines like you.. I just overhaul them. About the minimum you need to do one is some way of pressing them apart, I use a thick disk of steel with a slot in it, and a hydraulic puller, then V blocks or a set of centers, and some sort of dial gauge that reads thou.. A bit of angle iron to align them as you start to press the second half on and then learning how hard to tap them to align them.. basic hand skills. Seriously, a kid can do it..

" If there is any slop there the motor is junk. You'd have to split the case and send the crank off to be split and new rod installed and welded. It's not worth it.". They aren't that bad.. The rod kit is often about the same price as a piston, and they are easy to rebuild, it doesn't take much at all, a set of centers is the main thing, to align the crank when you assemble it. My sons used to overhaul cranks by themselves when they were thirteen, using my vices to press them because they found it too awkward to hold the puller, and pressing plate, all at the same time.. They broke two of my vices doing that.. little buggers.