Mech

You need to use a volt meter to look for voltage across places, and at times, where there shouldn't be any.. So from one side of the solenoid to the other should show battery voltage when you aren't trying to crank it over, but that voltage should drop to near zero when you operate the starter. If it shows more than about a half volt as it's cranking then there's a dirty connection in there somewhere, possibly inside the solenoid or in one of the battery lead terminals. Then check for voltage across(from one end to the other) of each battery lead while cranking, there should be no voltage shown.. if there is a voltage shown it's because there's a dirty connector or near broken lead. To speed things up you could check for voltage while cranking right from the battery to the starter terminal, if there's no voltage shown then those leads and connections are clean and tight and working. If there is more than about a half volt then there's a bad connection in that power feed somewhere so you start checking one lead and the solenoid at a time to find which one. Then do the same process with the earth.. from the battery earth terminal to the starter body should show no voltage while cranking. If there is a voltage then there's a bad earth connection somewhere, so check one lead to earth, then earth to engine, then engine to starter body.

When checking the starter leads, make sure you are checking from terminal to terminal, they can get bad connections where they crimp to the wires..

Yeah could be a leaking float needle valve, or the float level might be set too high, or there might be a leak between the float needle valve's brass housing/seat and the carby body.

Take the carby apart and pull the float out, then the needle and then the needle's seat. Check the "O" ring or washer that seals between the seat and carby body, then put that in and check the needle's clean and put that in, then fit the float and check it's height adjustment.

Ok. I've been keeping a look out for you...  I'll keep watching.

To go with the press you will need a couple of short lengths of what I think you guys call girder steel.. it's cross section is like a capital I... That's a capital "eye", not an "L". It needs to be big stuff, like six inches tall and about four across the two side plates. That's to support the crank on the bed of the press.

You also want a bit of angle iron about two inches by two inches. That doesn't need to be very long, about eight inches will be plenty. It's what you use to align the crank webs as you start pressing it together. You set the webs in the angle so they line up initially before you press the second web on. The books often say to use a special tool that's a bit of rod that goes through holes in the webs, but the angle does fine as long as you get it all sitting nice. You're also going to need those centers I was talking about.. Have you figured anything for that yet ? 

Before you press the old crank apart, take note how far the crank pin pokes through the webs. Mostly they are about flush with the web face but sometimes they poke out a little. It would be a good idea too, to make sure the new parts are identical to the old, in the length of the pin in particular. If the new pin's a bit longer or shorter then you'd allow for that when you press the new pin in. The rods sometimes seem a little different in dimensions or weight if they aren't genuine but that's ok..  As long as they are the same length anyway. .haha  Being a little thicker or chunker is ok.

I'll look for your posts.

Sounds like you need to fix the earth wire or connection, and it may not come out of gear because the gears in the diff are wound up and can't let the engaging dog slide till you back up a little.. that's quite common on a lot of things.

Simple things first.. You could try a new spark plug.. that black/rich could be caused by it misfiring. Misfiring could also be caused by some other electrical problem as has been said but those things need diagnosing and are dearer to fix..

The idle mixture only effects idling and a tiny amount of throttle, after that other jets take over. You should check the air-cleaner, and also, those things have an auto fuel cutoff tap which plays up sometimes and lets the sump fill with petrol.. check the oil level.. If it's too full, or if fuel seems to be disappearing out of the tank, check the fuel tap mechanism.

Do a standard tune, plug, aircleaner, valve clearance, then start to diagnose it. If you have a timing light it's an easy test to drive with it connected and watch to see if the spark starts disappearing as the faltering starts

Yeah, that isn't a good look for a new piston alright..  Good onya finding it.

Hi. How long has it been doing this, and did you do anything to it before it started doing this ?

And are you saying it sits there idling at the right speed for a while, then starts revving by itself ?

You should check it doesn't have air leaks between the carby and the head, and probably clean the carby and then check it's idle mixture adjustment.

Hi again. My problem with the movie is my crappy internet connection.  Yeah sometimes we can get blind once we've looked at a thing too long.. sometimes a new pair of eyes, or even just a break and when we come back it's obvious..

 So does the sound get louder with load ?  Which would sort of point to the bottom end, even though you are sure the bottom end looked and felt ok, and the noise sounds like the top.. but.. If it gets louder with a heavier load ? When you checked the conrod for play, did you make sure you were testing it at the crank position where the play would be on the crank pin ? If there's going to be play in the bottom end bearing it would show up a bit after top dead center, where the heavy load comes on. And did you check the play by trying to move the rod up and down, or by seeing if it would rock from side to side  which is the more accurate test. When you had the head off the second time, did you look for any sign of the piston hitting the head ? Was the piston genuine and did you use the genuine gasket at the bottom of the barrel ?

You say you can listen to it with the stethoscope, so I'm guessing this is stationary ? And you are sure the piston was a proper fit in the bore ?, though I'd expect that to be noisier when it was cold if it was loose, and then quieten a bit as the piston expanded.

Spark plug is the right sort ?  Couldn't be detonation caused by a too hot plug ?

Some of these things I'm suspecting should have been there before you pulled it apart, which would sort of have to mean the new noise is something you've replaced..  Piston slap or if the barrel was second hand, a ridge at the top of the bore ? It was a new piston and barrel ?

Running out of ideas now but perhaps something will prompt a new thought.. Keep us posted..

I can't listen to your movie.. so does this noise happen at idle, or only with a few revs, and does it get louder if you put a load on it, or does it rattle worse when there's no load on it ? In neutral, if you just gently bring the revs up a little and then back down again, does the noise come in as the revs are building up, or as the revs top out and the load comes off it, or is it worse as it slows down again ? And would the noise be at the speed of the piston going up and down, or only every second stroke, so on the firing, or perhaps something in one valve ?

Well... Did you ride it before taking it apart ? Could it have had the noise before you worked on it ? What was the original problem you were fixing ? So the timing chain stopped the rubbing noise, that's not the noise you have now ?

And.. does it make the noise when it starts up cold, does it get louder or quieter as it warms up ? Did you check the piston pin fit in the conrod ? And are you listening to the noise through a screwdriver to your ear when you say the noise is coming from the top end/valve cover, or is that just where it sounds like from a distance ?

Well since the cdi sparks when it wants to I doubt it's faulty.

In the smaller models there's a neutral relay that has wires going into it from the neutral and reverse lights and the kill switch and the starter button... If that thing has that relay I'd be checking it out and it's earth wire..  I see in the manual I have here for a 300 that there's also a diode in the neutral circuit.. that might be a suspect too.. You really need a workshop manual and then start tracing the power through one wire at a time going to the cdi unit. Check the neutral switch, neutral diode and neutral relay..  I reckon the problem will be in there somewhere..If your 500 is like the 300.

Hi. You can't fit a regular clear plastic filter to a fuel injected bike.. They have about forty pounds of pressure in the lines and it could burst and start a fire.

I'd be suspecting an electronic fault. That time related aspect sounds like an electronic component getting hot then failing, then cooling and starting to work again. I'd suspect cdi or ecu.

That said, there was a case in here the other week that turned out to be a tight valve clearance. Checking the valve clearance would be a good idea.

And, in all problem diagnosis they always say as the first step.. do a standard tune and check everything is to specs.. So fuel pressure, voltage, aircleaner, tank vents ..  It's boring but you really want to know everything's right before you start fitting parts..

Dang... Posted in the wrong thread..  Problems with a slow connection.. Haha

So is the battery going flat while the bikes parked up, or after two days of being used..

I'd be checking the charging system's working.  Put a multi meter on Dc on the battery while it's running and see it's got at least thirteen volts. Then I'd put the gauge to AC and check the power for ripple.. if it has a faulty diode in the regulator there will be some AC showing, and a dud diode could be what's draining the battery.

Hi. You can't fit a normal clear plastic fuel filter to a fuel injected system, they have about forty pounds of pressure in the line.

I'd be suspecting that your problem's an electrical fault, and an electronic fault to be exact.. So cdi unit or something in the ecu.  The fact it takes a certain amount of time, rather than load or throttle to cause it is what makes me think that, and the fact it takes a few minutes to cool down again. Overheating electronics do that.

That said, there was a case in here the other week with similar symptoms and it turned out to be tight valve clearances.. as the engine gets hot the valves must have been loosing their clearance and holding a valve open.. Perhaps check them before trying a new cdi or ecu... 

The symptoms don't really sound like the advance curve. Have you had a timing light on it ?

The five you returned, are you saying they wouldn't even make a spark ? Because that sounds so unlikely that I'd have to suspect you have some other problem. Have you checked the wiring, and the trigger and stator outputs ?

I think I've seen a few instances in here and other places of yamahas having wiring problems up around the steering head.. 

Ok, well I'm not sure what's wrong but it sounds like the bike's trying to start off with the driven pulleys too far apart or the drive pulleys too close together. Either thing will make it seem like it's in too higher gear. Since you've had the driven pulleys and centrifugal clutch hub apart I'd guess you might have assembled that wrong. I think you will have to take it apart again and check how it's assembled and that everything's nicely lubed and free to move.

I think that if you look at an Arctic Cat manual it will be pretty much the same. There's probably  manual on this site.

So what was the original problem with the clutch, what was it doing ?

And was it the belt you changed ?

And just to confirm, it didn't have this problem before you changed the clutch/belt.. it was some other problem ?

And did you check or notice whether the two pulleys could change their inner and outer plate's, distances apart ?

Was there a lot of chewed up belt in there, and did you clean it all out really well ?

It sounds to me like the changeable diameters of the pulleys isn't operating correctly, possible just dirty with chewed up belt.

Hi. I've never heard of a linhai. Does this have a manual clutch, with a lever on the handle-bars, or is it an automatic clutch ?

It sounds like the key switch isn't letting power get through from the battery to all the ignition fed things, and it's not letting the charging power back through from the charging to the battery. But when the motor's running the charging's running everything that should normally be fed from the battery. so the lights and starter work.

Hope that makes sense.

Found it...

§2381. Treason

§2383. Rebellion or insurrection

§2384. Seditious conspiracy

§2385. Advocating overthrow of Government

Trump was inviting the Russians to interfere in the elections..  As a by the by..

Now they are saying his talk is sedition.. That is so far short of what he's been doing ever since he got in that it's a joke.. It's been deliberate treason from start to finish.

What's the punishment over there for treason ?

Ha good one.. getting hot and tightening up..  I've seen it before on things, but normally with a whole lot of spitting out the carby.. 

In all the manuals for auto stuff the first thing they always say we should do is, do a standard tune and servic and check everything is to spec...  Boring !!  Haha.

Sounds good Billy.. A late christmas..  Hope the little fellah's keeping you amused.

Auto parts store should have one.. Take a sample.

And there we go... Burning the place down as he leaves..