Mech

It's not likely to have blown all it's gears.. I'd check the final drive where the driveshaft joins the engine..

Yup Gw's right there.. The choke plungers are often different, and so are the idle mixture screws different sometimes if it's an aftermarket. The idle screws can't be changed but the choke plunger can mostly.. but it might not always be so.

I thought you might have.. easily done.. You should check whether it does it in all the gears 86 in case it's a final drive making the noise...

This isn't what a worn clutch does.. The clutch may be worn, but then it wouldn't transmit enough power to make the gears slip. And clutches don't make noises, and they don't grab and buck. There must be a problem with the gears I think.. or the final drive ?

Whenever you split the cases it's really important to be absolutely certain the gear shift is operating at every stage of the reassembly. The gears and shift is the one thing that gives people the most trouble in my observations. Don't assume it will change properly once it's together if there seems to be any problem in the early stages of assembly. The gears and the shift\ barrel should all do their thing before the second case even goes on, and they should still all work once the cases are together and tightened. We nearly always have to rotate one or both shafts to get the changes to work, but it should get every gear and that spring loaded roller that presses against the shift barrel's start washer should move the shift barrel once the roller has gone over the top of each of the star washers bumps. It's that roller that moves it into each gear once you have started it moving with the shift lever, and the roller is what stops it vibrating out of gear. Here's an extract from the honda manual. read it all and look at everything in the diagrams, there are pictures and fine print that explain how the shift lever is meant to engage with the shift barrel. output.pdf

Yeah the plunger needs drawing out for choke, and they only work at idle, and it needs to be a slow idle, with the butterfly or slide closed right down. They draw extra air and fuel around past the butterfly or slide and that doesn't work unless the throttle is closed off .

Ok.. well I can't think of anything specific that would cause that but it sounds like you've narrowed it right down.. I presume you mean the barrel that shifts the forks is seizing up once it's retainer is done up ? You can check that just by trying to turn it with a pair of slip-joint pliers. See how much you need to loosen it's retainer off to get it free and moving. If that has a ball bearing, perhaps the bearing is the wrong one for the job. Bearings come in different widths and that is probably meant to be a thin one. Other than that, if loosening the bolts is enough to free things up then it would seem it only needs something like a shim, or a gasket to make it right again, so check the parts book for any thin shim/washer/gasket that's missing. Then.. if nothing in the side case is causing it, It might be a shift fork in wrong ? Would those be possible to muddle ? Some are and some are well marked or designed so they can't really be muddled.. Perhaps take the shift barrel's retainer right off and check the barrel for end float. Then fit the retainer again and see what happens. A bit of trying things should reveal what the problem is..

That doesn't sound like any slipping clutch ! That sounds like jumping in and out of gear. I don't think it's going to be in the side case.. but start there and hope. Perhaps try all the gears first and see whether it jumps out of several or perhaps it's just the one gear. I think I'd ask the buddy about whether it had been doing that before.. Just sitting around unused doesn't make them jump out of gear, and when they jump out of gear forcefully when under load, which is what it sounds like you are describing, it's normally the engagement dogs on the gears. If it's just one gear and one of the lower two gears, it might be that there is no crashing of gears nosies because it may have a gear pressed onto a shaft which can slip under load. That makes them buck and jump but there isn't any gear graunching noises, just a squawk sometimes as the gear slips on the shaft.The manual will warn you about using a gear like that, they say not to press them off and back on the shaft more than once or twice. Not all gearboxes use that system though so that's just a guess. Just occasionaly there will be something preventing it getting it into gear, or that spring loaded roller is broken causing/allowing it to rattle out of gear, both of which will be in the side case. If you can't see anything there in the side case I think it's going to be a complete strip down.

If it idles good then I wouldn't expect it to have a manifold leak.. I'm thinking the coolant temp sensor, the air temp sensor, the air-flow/barometric sensor, or the throttle position sensor showing the ecu a wrong reading and so causing the mixture or timing being thrown out and making it run bad.. It would be an easy thing to check if you could connect a laptop or had the dealer ecu reader. Otherwise it's a matter of getting the manual and a multi-meter and starting to test/check all those sensors. If all the sensors are delivering the right figures right at the plug going into the ecu, then I'd check all the earths and power supplies to the ecu and all the sensors, and if all of that's good then the manual will say to try a known good ecu, or try the suspect ecu in another bike..

I can't make out the photos.. I'd try holding that spring loaded roller off a little and turn the shift drum by hand, while rotating one or both gear shafts, and make sure the shift barrel/drum and forks and cogs are all moving, in case something is being pinched by the cases, then I'd work on/look at the linkages.

Having the wrong oil doesn't make such a difference that the clutch will slip with just a little throttle. You have either a worn out clutch or it's badly adjusted or.. you say it seems like the trans is jumping out of gear.. If it was jumping out of gear it would probably make some noise, either a bang if the gear was under load, or a crashing of gears as it tried to get back into gear or into the next gear.. Try and check it isn't jumping out of gear, and then if that's not the problem you need to pull the case and check both clutches for wear.

In post 33 you say it was moving the shift forks when the cases were apart.. that was the center cases that were apart ? And then it locked up when you put the cases together and bolted them up.. Have you/did you try the shifting with the bolts backed off a bit ? It sounds like the center cases have no end float on one shaft..

That sounds like a real piece of sh**.. I would have to fix that ! That's not firing at all when it's missing like that. . Are you sure the plug's gapped right ?

Yup Injector cleaner may help.. Simple thing to try.

You need a service manual. There's likely one on this site to download. That will tell you how to check the temp sensor. The manual should say how to test the throttle position sensor and the air flow or air pressure sensor.. Any of which could cause this, (what sounds like), lean mixture. If you can you could also check the fuel pressure. That can be checked with a bit of experience just by holding the fuel hose to the injector while you turn the key on. The hose will bulge if the pressure is the required 50 pounds. If you can barely feel the hose stiffen or bulge then it might be low fuel pressure. Tell us more about this problem.. Have you had the bike for long, has it been parked up or did the problem start while you were riding along one day, has it got gradually worse and how long did it take to get this bad, or did it just happen over night, is the fuel fresh.. ?

Thanks Krazo..

Ok, that's helpful.. Might pay to check the temp sensor reading. I suppose you have checked for trouble codes ? What year is this bike ?

So this is a fuel injected bike right ? If the plug's not getting fouled by the oil then the oil probably isn't causing the rough idle. First thing I'd do was do a basic tune, plug, adjust the valves, clean or change the air-filter, check for any air leaks into the inlet manifold, vacuum hoses, change the fuel filter, check the exhaust for leaks, adjust the idle speed and mixture if that's possible.. If it's EFI I'd check for trouble codes. I'd also check the compression. Then I'd take it for a ride and check how it ran under a load, and on very light throttle settings. EFI engines are tricky beasts and they self adjust a lot so they don't behave like carb bikes do when they have a problem. Quite often with EFI the symptoms are mainly things the bike is doing to compensate for some very small problem(like a big plug gap) that you'd hardly notice on a carb bike. Any small differences you might see in it's running now compared to how it used to run could be important.

Well the flywheel should have a key to align it with the shaft, and a nut and washer or possibly two washers.. so you'd better fish them out of where-ever they are. Then you need to hand fit the flywheel onto the shaft without the key or nut and turn the flywheel on the shaft(shaft not turning) checking it fits on nicely with no rocking or wobble to it. If it sits on the taper nicely then take it off and fit the key and flywheel and give it a bit of a wobble to make sure it is still sitting nicely and not being held off-set or not right on because of the key. Then if it's still fitting nicely fit the washers and nut and tighten it and use something close against the flywheel as you trun the flywheel checking it's running concentric and not bent or wobbling. If you mount something right close to the flywheel you will see the gap changing if it's bent. If it all looks right then use a socket and bar and tighten the nut up. Don't use an impact wrench because you won't notice if the threads don't feel right.. Use the bar and tighten it down checking it behaves as threads should.. going up tight and then progressively tighter in the last 1/4 or so of a turn.

Have you had the spark-plug out and checked.. The oil might be fouling the plug. Check the plug for traces of oil or carbon caused by burning oil, and change the plug if it's dirty. EFI engines are quite particular about the plug condition and gap. Smoking at start up is often the valve guides leaking oil down into the cylinder when it's sitting. Rings smoke under different circumstances to valves.. If the plug is oily we can do some tests to tell if it's rings or valve-guides.

This should help... Sportsman-2004-700.pdf

If pressing the start button does nothing at all, no dulling of the dash lights, no clicking noises, then you need to get a wiring diagram and check the power from the key switch is getting to the kill/start switch, and through it and to the start solenoid.

I think that manual is FAS when it opens.. You need to read the whole manual and follow the diagnostic process really.. You sound like you already know it's better to diagnose and repair the right part than to throw parts at it randomly.

This is for the 660 2004-2008.. Might get you started. output.pdf

I had a look in the manuals and there isn't one for that bike. You might have to look at a few of that cc or year in a different cc and try to sort of meld the two diagrams together in your mind to figure what it has. If you have a model designation off the ID plate I might be able to find a manual.. They have another model designation, something made up of five letters and numbers.. Ed3f2.. Something like that but it might be any letters or numbers.