Mech

All good Brother. Most jap machines actually come apart fairly easy. Sometimes we have to pull some body or other auxiliary bits away, but then things mostly come out pretty nicely.. Not that I've worked on one of those. But I'd do as you are and spend a bit of time contemplating which way is going to give the full access. Nothing surer than us thinking it might just slide through the gap.. and then finding we're moving it the wrong direction entirely.. haha. And yeah, your idea about it not producing it's own power like it should does make sense, that combined with a capacitor in there could explain it to a degree. I'm still stumped about needing the wire back attached again.. That doesn't make sense. See in the wiring diagram on the coil there is a rectangular box shown in the primary circuit, well in electronic diagrams they use a box like that to represent an integrated circuit. That could have a whole bunch of electronics built into that chip. Since it sparks a bit then the secondary windings are ok, and if it's getting triggered at the right time then I'd assume the primary windings are also ok, and since it's almost certainly the primary windings that produce the power to run the chip there should be the power there, an open circuit shouldn't/wouldn't come right by putting 12v in, and so it really only really leaves an internal open circuit or a faulty component inside the chip(resistor, capacitor,transistor etc). I think.. But... Weak magnets can cause problems.. Rare these days because we have better magnet materials, but flywheels that sat unused, or worse still removed without a keeper across the magnets used to get weak and then the charging got weak. Maybe slip a bit of steel past the magnets and make sure they are nice and strong.. Ok, that's the musing for the day.. haha. Good luck. I'm going to go throw a rope up a tree to climb up and cut branches off. That's nice and straight forwards. You can wish me luck though, I'm going to be fifteen metres up dangling off a rope wielding a chainsaw.. haha. Life in the country.

Changing tyre sizes is not as simple as it seems. If you aren't careful you will get gear/axle binding, and perhaps a badly behaving drive system/clutch if it's a belt drive model. I'd stick with yamahas very well thought out design.

And you're sure the service manual is for the right year and stuff.. The wiring diagram and the diagnostic procedure both point to a faulty coil.. Why it would do the things you are describing is hard to fathom. That kill wire should be open circuit between the wire and earth when it's disconnected from the the ignition coil, and the switch is on and all the requirements for starting and running are satisfied. I'd check it was open circuit and not earthed, and I'd perhaps leave a volt gauge on it while I tried cranking the engine.. Perhaps that combination relay does feed it a bit of voltage to start it.. It's not described in that diagnostic chart, but I'd monitor the kill wire..

Ha.. yeah thanks for that. That makes it even weirder.

#31. Yeah well that's real weird, and it's possibly as you say and you are charging a capacitor, that would sort of explain a few sparks for a while before it dies again. The spark is after you've stopped putting the 12v in right ? It's not a spark being produced while the 12v's being applied.. because.. it might be a later model with a 12v ignition.. Perhaps. If it is a magnet run ignition though, then I'd say it's crook, but I'd always want(as we both do) to confirm that somehow.. I wonder if the dealer can test it for you ?

There may not be anything wrong with the bike. It's common for gears to jamb hard against one other if the engine stalls, and it makes them hard to shift. It can happen in forwards or reverse. First thing to try is rocking the bike backwards and forwards quite forcefully while you are trying to move the shift lever. The rocking removes the load off the gears and hopefully they will slide apart. Another thing that often fixes it is, most quads have a feature where if you apply the brakes hard enough for the brake light to come on, then the electric start operates even though it's in gear. If you can use that feature to start it in reverse you will probably find that after you've backed up a foot or two that the gears will shift normally. I'd try those two things first, then as Gw says, check the gearshift adjustment, and any safety interlock that's to prevent it engaging a forward gear while it's in reverse. Not all bikes have such a feature but if it has a lever or knob you have to operate to get reverse, check it's adjusted right.

I always aim to change everything that is needed, and nothing that isn't. There's always something better we can do with the money..

Yeah well you're onto it and I'm not there.. haha. You can test the drive sprag by putting the bike in a forward gear and try pushing it. If the sprag is working, and the gearbox shaft/clutch basket, (which turns with the kickstart), turns faster than the crankshaft(which in this case is stationary), then the sprag should lock and turn the crank. If the gearbox shaft or the kickstart turn the clutch basket faster than the crank is turning, then the sprag locks. That's what gives engine braking at low engine revs when the centrifugal clutch has disengaged. The common symptom of a faulty sprag on a quad is they run away down hill once they have slowed to just above idle speed.

A Honda mower .. It sparked once. Checked it's earth ? That will be through the mounts. I'm assuming it will have an earth, but.. since the two plugs make an HT circuit, and the internal windings are all internal, perhaps it won't. If I was in there I'd clean the mount anyway I think, and check for the rust flakes. And if the spark plug leads come out check them of course. If either plug lead had an open circuit then neither plug will spark. If a cap or lead had a short to earth then the other plug should still spark. A lot of small engines use a similar system, and you might be able to find something made for the honda, or just a generic coil with built in controller. They (generic) can be got easily and cheap for small engines. They likely make them for twins.

You guys have great prices over there, and choices. Here batteries are two-hundred bucks, and even with the exchange rate that makes them dearer than they should be. It's freight, which has gone crazy since covid. I bought a starter bendix for an old inter bulldozer the other week, it was a good price at $33.oo American, but the freight, which once would have been twenty bucks kiwi, was $66.oo American.. My sixty kiwi buck part cost me over two-hundred kiwi bucks !

Howdy. I'm in New Zealand.

Those sprag clutches are really robust and hardly ever give a problem other than getting dirt/grit/metal dust in them, of which it only takes a very minute amount to make them slip, but if they get washed and washed in thin cleaner, like fuel or white spirits, they come clean and work fine again. I've washed heaps in bikes, both clutch and starter, and in auto trans which always have several of them, and they've always passed inspection and gone back in perfectly fine and done their job. I've never replaced a sprag in a bike or auto, and I've handled dozens and dozens of them. Car starters have them but they are sealed and can't be washed, and they get dry and rust too, so different story there, those we replace. I've talked people in forums into cleaning them, and after they reckoned they washed them good, I convinced them to wash them more and more, with lots of shaking about in clean fuel, and eventually their sprag clutches have come right. People replace them unnecessarily.

It's all internal to the coil. The magnets induce a voltage in the primary windings, the voltage is allowed to flow through the windings as a current, in the old days through a set of points, now days through a transistor, then, back in the day, when the points opened and the current stopped flowing the voltage flowed into a capacitor to help prevent the points burning, but also to increase the counter flow of voltage that developed in the primary windings as the induced magnetic field collapsed. Now days a transistor stops conducting instead of points opening, and there may or may not be a capacitor in there(I don't know). The collapsing magnetic field, combined with the voltage getting reversed as it goes back out of the capacitor, causes a high voltage to be induced in the secondary windings and so a spark. The wire coming out is only a kill wire.. Some of your old bikes will have a long core with a winding that spans two of four magnets in the flywheel, and a set of points. That winding either powers a separate ignition coil up on the frame somewhere, or in old machines it powers a secondary winding that's wound right over the top of the first(primary) winding I described. The second way with the secondary wound over the primary right there inside the flywheel is mostly on stationary engines and the separate coil is more common on newer bikes, like the sixtes and seventies bikes. Real old bikes, with a villiers engine say, they used the old system too.

Yeah. And the honda ones are real annoying I think. I like the suzuki levers.

haha. Yeah I'm always telling people that nothings ever simple. The thing is, that we all need some satisfaction in our lives, and there's no satisfaction in just doing the simple things. We need to do the hard stuff. It's good for us.

If it is close to the magnets on the flywheel, and in air, check carefully for flakes of rust, or a pile/finger of rust, bridging between the magnet and the core of the windings. If a tiny piece of steel bridges the magnet to core it shorts the magnetic flux. No magnet no spark. The little slither of steel can flick up and down and make for intermittent spark at slow revs, and then either run, or kill the spark. I just use a dry rag to wipe rust or flakes off the magnet, which is where it generally is.

And the spark is going through both spark plugs at every firing, one on each end of the secondary windings, so both plugs need to be connected or neither will spark.

I was imagining the coil must be right by the flywheel. Something like a chainsaw or small stationary engine has.. lawnmower in fact(of the walk behind variety). The diagram shows the primary windings being a loop, with a small box in the circuit. The small box is doing what a set of points did on some small two-stroke bike forty years ago.. You'd know them well.

This paint hardener is a new one to me. I don't paint ! My house is oiled with linseed.. haha. My machinery's sprayed with linseed.

Yeah I suspected it might. Thanks. It just saves that preferred view on my linux I suspect. I haven't started the windows system for literally years and can't remember if it works in windows.

Yeah it's either super-ceded or an aftermarket, designed to overcome some weakness I'd guess.

Yeah that's the thing. I haven't looked in the book but that's an interlock between forwards and reverse, so you can only engage one at a time, and the other's locked out. It might be keeping forwards locked out. When it shouldn't.

Looking good.

I don't know exactly how the setup works, but there is a cable that operates a safety on reverse, and if that isn't adjusted right it could be not moving/giving enough after reverse has been deselected and so it's preventing forward gears being selected..

Ho yeah, they are quite a bit different. So the other gear in there must be different too or it would be chewed up. You'll suss it. If it's not a market difference(thinking starter motors) then it must be some after market I reckon. Those chunky teeth don't really look like what a honda would have.. haha.. maybe. Or a honda mod.. There's probably a "old new stock" dealer somewhere with a set. We have one here called Anaconda.. They have a lot off old stuff.