Mech

https://www.babbittsonline.com/oemparts/a/hon/5053de37f870021c54bddb6f/front-crankcase-cover-trx500fe-fpe Part 21 is attached to the gear shift mechanism and when the shift lever moves any direction it swings part 13 left or right. Part 17 is a housing with three ball bearings in it, and it, and parts 13 and 15, all work together to lever 13 and 15 apart. Part 13 pushes against the cover and 15 has the adjuster screw in it's center. The adjustment screw presses and disengages the clutch. So yeah, it looks like it may be needed to take that cover off. If you have it off and are putting it together again, use a bit of vaseline to stick the bits in place while you fit the cover.. It saves/stops then falling out of position.

At such low pressures it's almost certain that the rings and the valves are at fault here. You say the valves were not to spec.. so were they too tight or too loose ? And I suppose there's no sign or sound of the head gasket beingreally badly blown ? No whistling or whooshing (haha) sounds ?

Yeah compression that low it will be a valve problem. If the/one valve has a lot of clearance it might be that valve sticking open.. Try tapping it and/or turning it ..

Check the valve clearance.. Check the cam timing. Then check the compression with a gauge, then put about two teaspoons of oil down the spark-plug hole and check the compression again. If it comes up by more than about twenty pounds (depends on what the first figure was) then it's an indication the rings are leaking/weak, if the two figures are almost the same then it's probably a valve. If it has more than a hundred pounds then it should run, just, but be hard to start.. Less than eighty and it's unlikely to start at all.

Yeah ok. So when you get the new rings, check the holes in the back of the oil groove are clear, check the side clearance of the rings (that's the clearance top or bottom of the ring), and check the ring gap of course. When you get the bike together, check it all over before you start it, then when you do start it, check the oil is getting to the head, then start riding straight away, don't let it sit idling, and when you are riding it, put a heavy load on it until it's built up about 3/4 revs, then let the throttle right off till it's slowed to just above idle revs then give it about 3/4 throttle again and keep it there till about 3/4 revs.. repeat that cycle about ten minutes or so and the rings will bed in.. That first few minutes is more important than hundreds of miles of careful running in.If you bed the rings like that, the engine doesn't need any running in. Let it sit idling and the rings might never bed in. The rings have to have a heavy load on them in the first few minutes.. That means letting the engine labour slightly..

You could check the engine breathers. They generally run from the crankcase to a branch where one hose goes up the front, around the fuel filler and then down a little, and the other branch goes onto a restricted vent into the air box. The restricted vent in the airbox is only to stop water getting drawn up the main breather if you drive into deep water. it breaks the vacuum. They also often have a short branch going down the bottom of the bike somewhere with a plug on it, that's to drain water out if any does get drawn in. The main vent hose can get blocked by dust and oil, and then if you undo the filler while it's running there will be pressure. You could test that and/or check the main vent hose going up front and high is clean.. If the filler plug gets pressure, the vent isn't clean.

Ha.. Very good. You said you used a barrel and piston and rings off another bike that didn't smoke.. Then later you say you think the head must be good because the bike didn't smoke.. So you did swap the head off the other bike too ? The cam timing being a tiny bit off wouldn't make it smoke.

You should have checked the valve seals, and possibly for leaking between the guide and the head when you had it apart.. The exhaust valve sits in a puddle of oil and if it leaks the oil goes straight down the exhaust pipe and gets burnt.. That could be your problem.. I understand it's getting oil into the cylinder too, and that could also happen once the engine is stopped, then the oil can drip off the valve and into the cylinder. It's also possible that the new rings didn't bed in, and that could let some oil get up into the combustion, but for it to burn as much oil as you are saying the rings would have to be really seriously damaged. Just having the ring ends aligned or not, doesn't really make that much difference. Repositioning the rings alone won't cure the problem. For it to burn that much oil in one tank of fuel it should have fouled the spark plug several times over.. I'd have to suspect the exhaust valve over your ring fitting job as being the culprit.. Were the ring gaps correct ? Did you de-glaze the bore a little ? Did the barrel slide down over the piston nicely ? If yes to all those then the rings shouldn't be letting that much oil be burnt.. If you have the cylinder head off again, take the valves out and block the head up so the exhaust valve guide is pointing up, and you should be able to make a small puddle of fuel around the guide, but not deep enough to run down the guide..Leave it and see if fuel leaks down the side of the guide. If you can't get the puddle deep enough like that you could put the valve in and test the guide and the seal at the same time.

Oh.. I'm stupid.. haha. When did we start talking about this one.. kidding.. I do remember you coming back with a new bike now.. I should pay more attention.. Ok, so it does take about 3.5L.. And after a run (to circulate the oil and leave a bit in the head {which holds quite a lot [especially around the exhaust valve] }, and other places, and with the bike off, the oil should be half way up the sight glass.. And if you undo the filler cap, no oil should come out.

Well I don't know where you got the 3.5l oil capacity from but I've never seen an LT250 that took more than two litres, and they definitely aren't meant to overflow back out the fill hole. No I don't think it needs flushing with diesel or kero.

If the engine burnt as much oil as you are saying it does, then it wouldn't run. I've seen exhaust valve guides loose, or leaking between them and the head, and/or worn exhaust valve seals, let heaps of oil straight into the exhaust, and make a huge amount of smoke, but the engine run quite well because the oil wasn't getting into the combustion chamber. Those suzukis have the head tilting forwards and the exhaust valve guide and seal gets deep in oil. If there is oil getting to your valve gear then the oil pump is fine. I doubt the engine is meant to have three litres of oil in in..

#107, Not sure about those figures. They might be ok. But unless the starter works by turning the key against a spring for start, then I think you've misunderstood the wiring diagrams. Try using the ohm gauge and check which contact/wire gets connected to which other wire on the back of the switch's plug, and then check that when they are connected they have less that one ohm resistance. I think you'll find there are two wires that get connected when the key is on, and disconnected when the key is off, and another pair of wires that are connected when the key is off, and disconnected when the key is on.

That oil seal #17 is too keep oil in the crankcase and out of the pull start cover. That's not your problem. The LT50 they were talking about is a two-stroke. Blocked breather hoses could make it smoke, but disconnected hoses won't make it smoke. You leaned it over on it's side and the smoke went away, you set it down flat and the smoke started again.. There's too much oil in the sump.

Inside of the side cases there is oil, and the generator and timing marks are in there where there oil is, but generally speaking they design things so the crank throws and flywheel don't get in the oil, they'd make too much oil mist and breathers wouldn't be able to separate the oil out fast enough, and as I've said, it wrecks the ring's seal.

I'd suspect that when you think you are seeing low/no oil in the sight glass, you're actually looking at clean oil that's right above the sight glass. Regardless of what the oil level was or is, if fuel gets into the oil it raises it's level, and, when you start them up they evaporate that fuel fairly fast once the engine starts getting warm, and that evaporated fuel gets into the cylinder and makes the bike run rich. Having the oil level too high splashes it up the bore as I say, and that's probably why your bike stopped smoking when you tilted it over.. (good test by the way..).. You need to check the operation of the fuel tap, and perhaps the float level needle and seat operation. I've got the fuel out of bikes just by letting them idle till they got fully warmed up.. Done it a few times with varying amounts of fuel in the oil and it's always worked and doesn't seem to have had any detrimental effect on the engine. If you load the engine with the runny oil though it might damage the bearings.

If the fuel tap doesn't shut off, for whatever reason, then the fuel can get into the oil. If oil gets onto the crank throws, that's the webs or counterweights that make up the crank, then it flicks so much oil up the bore that rings can't control it and engines smoke. If the flywheel is getting oil on it I'll bet the crank throws do too. If you want to lower the oil level while you are looking for the timing mark you could just lift one side slightly and the oil will run away. If you look at a parts diagram you will see there's a big drum in behind the pull start, and that, can be turned by hand or with a screwdriver through it. There's no oil behind that cover and it's a good idea to take it off and check if it's dirty in there, and to move those small bolts.. The cover has a paper gasket, but some of them used to have a dimple in the steel to let water out anyway..They hardly need sealing.

You can test them while you're holding them in your hand by blowing into the fuel fitting while you slowly tilt the carb in a way/direction that will make the float slowly swing from it's hinge at the top, towards closing the needle onto it's seat. You have to hold it so the float's hinge is going to be at the top. It should blow through freely when the floats hanging away and block off entirely when the float is hanging even just lightly against the needle.

Ok, well, the oil shouldn't be up to the flywheel. That might be why you are having smoking problems. You should check the oil isn't full of fuel.. They do that if the fuel tap is playing up. Other than that, check your oil filling procedure. And.. I always take the pull start cover off and turn the crank with the drum that's in there.

Hi. The float needle will be stuck a little open. Well unless there was some dirt in the fuel fitting before the carb went on. if it's just a stuck float needle then a tap fairly hard with a screwdriver handle, done with the end of the handle so it's got some force, and right by where the float needle seat is going to be, quite often cures that. Or you leave the tap off, wait for it to dry off a bit then start the engine, run it till it starts to sound like it's getting low on fuel in the carb bowl, then turn the tap back on and keep listening to the engine while you keep it a bit above idle revs. If it starts to run rough and belching smoke then the float needle's still leaking.. probably got a bit of fluff on it. To be real sure before pulling the carb off again I'd repeat both those things again.. Or even run it right out so the needle drops a long way down, then turn the fuel on hoping it flushes a speck of dirt out and lifts the float and needle better this time.

haha.. That's right Viaco.. People complain to much. This is a good site.. It refreshes the pages fast, it's well organised and run, the admin is helpful and obliging if you have problems, and it has the books.

Switches can get no or dirty contact because of dirty contacts, or they can have wear that gives them lost movement, so when you move the key or button they don't slide the contacts far enough to turn right on or right off. In the case of the kill switch it could have rust in it that could be enough to partially short out and give bad running. Dirty contacts can generally be found using an ohms meter, but for the key switch it's better to do a "voltage drop test"..Google voltage drop test. Make sure you understand how a voltage drop test works, and how that relates to a key switch.

You can test the main jet by test riding.. It need a good bit of track where you can hold it at top speed in one of the high gears for a couple of seconds though.

Bigbell, I doubt that changing an exhaust would need more than one jet size difference. It's possible they didn't even change jets. I'd forget trying to figure what size your bike had originally and just tune is as you find it now.

You are going around in circles here NHWQ. It's really really important you work through your possible faults eliminating them one at a time by doing a really thorough job and making sure that one thing at a time is right. Just looking at things and deciding they look fine isn't enough, you have to know they are fully functioning and correct. By now your carb should be clean and set up right. The only thing that should possibly alter/go wrong in the carb is the fuel level if the float needle or seat is defective, has dirt getting to it, or is leaking under the seat. Those problems, which do occasionally happen temporarily, can generally be cured by turning the fuel tap off for a while. Try turning the fuel tap off and start riding, when it starts running out of fuel turn the tap back on and keep riding. Check whether it goes better as the fuel runs out in the carb, or when the tap is on. Do it repeatedly till you are familiar with how it runs at all speeds, loads and throttle openings both with a full carb, and as the fuel level drops/is low. That way you will diagnose whether it's a fuel problem, and you will hopefully become familiar with the symptoms of low or enough fuel, or if it turns out it is flooding, what a flooding carb does.

The parts places sell them from 125 to 148 in steps of two or three. That's a huge range.