Mech

View File Linhai/Massimo T-Boss 550 Owners Manual Linhai T-Boss Owners Manual Submitter Mech Submitted 11/14/2023 Category Other Brands UTV  

View File Linhai T-Boss 550 Service Manual Linhai T-Boss 550 Service Manual This manual was produced by the Linhai Group primarily for use by Linhai dealers and their qualified mechanics. It is not possible to include all the knowledge of a mechanic in one manual, so it is assumed that anyone who uses this book to perform maintenance and repairs on Linhai vehicle has a basic understanding of the mechanical ideas and the procedures of vehicle repair. Repairs attempted by anyone without this knowledge are likely to render the vehicle unsafe and unfit for use. Linhai Group is continually striving to improve all its models. Modifications and significant changes in specifications or procedures will be forwarded to all authorized Linhai dealers and will appear in future editions of this manual where applicable. Submitter Mech Submitted 11/14/2023 Category Other Brands UTV  

I was thinking something like tyres wearing differently front to back that had caused a gradual difference between front and rear ration.. causing binding. Try slipping it in and then straight out again without moving. If it comes out then , then it is binding up. Or, try slipping it out while the bikes moving, and in particular try blipping the throttle just as you go to slip it out so the load comes off the gear. Also perhaps try driving straight backwards without turning and then again turning the steering to see if that makes a difference.. If any of those things makes a difference then it's probably a binding up between front and rear putting a load on the gears. Other than that, some part of the linkage going over center ? So it has good leverage pushing into gear but then goes too far so the lever is at a steep angle.. But that may not be an option in the case of a yammy..

You'd already know the obvious ones.. fast idle or binding between front and rear.. Does it do it if you haven't moved the bike ? Like if you just slip it in and then try to take it out again does it do it ?

Ok.. Well if the new coil cures the problem you'd better try to figure why it's killing the coils. I'll have to go have another read of the manual..

It's always worth trying a new plug too.. Cheap, and if it's not the cause it's good to have a known good one for future diagnosis sitting on the shelf..

You should check for trouble codes as a first step. To check the ignition system (if there are no trouble codes indicating a faulty crank position sensor) you should check the coil's resistance, which should be 0.1-0.6 Ohms from the terminal to the ground, and 12-19K ohms from the spark plug lead to ground. Then you check the peak voltage when it's cranking over, and with the coil connected, and that should be at least 5v. That 5v though is only an instantaneous pulse and you need a good gauge to read that. You shouldn't get 12 volts to the coil.. That tends to suggest the computer is playing up or there's a wiring problem. If the book you are reading says you should get 80v then you might have the wrong book. If there is no 5v pulse then disconnect the plug at the ECM and check the wiring between the coil B/W wire and terminal 7 for open circuits or shorts to earth or power, and check the W/B wire to terminal 1 for the same things.

Did you try the spark using the pull start ? I don't remember the previous post but if I suggested testing it on the bench then I presume it's a 12v ignition coil and so if the starter is drawing too much power or the battery is weak it might have a weak/intermittent spark when cranking. That though shouldn't cause it to die once it's going and driving. You didn't say you'd checked the fuel is coming out of the drain screw at a good rate... I still suspect from your initial description of the symptoms that it's a fuel related problem. If the spark is getting intermittent while you are driving it I'd expect the bike to start behaving differently than if the fuel's running out in the bowl.. When they start running short of fuel the power generally starts to fade away fairly smoothly, but if the spark is starting to get intermittent I'd expect it to start having a definite miss-fire and perhaps some back-firing out the exhaust, If it looses spark entirely then the bike will come to a sudden stop, but running our of fuel they generally keep trying to run till it's all gone and they will often recover if you back off the throttle a little.

Brass and aluminium have a bad habit of corroding badly when they are together with water. The zinc in the brass is the trouble. Silicon bronze is better, or insulating the two materials with something like the thread tape the yamaha mech suggested might work if the tightening doesn't cut through the tape. Those water pipe fittings are also availiable in steel though which will possibly out last anything that sets up an electrolysis reaction as the brass does.

Have you done any preliminary diagnostic work, such as checking for spark on the miss-firing cylinder ? Checking whether that cylinder's plug is getting wet or if it's dry when it's miss-firing ? Most injectors vibrate when they are firing, if you put a finger on it you might detect one not going properly. And, have you noticed any circumstances that seem to cause the problem, such as wet weather, after it gets hot, only on a cold start, after a certain amount of time regardless of load ?

Going 300 metres before conking out, and pettering slowly to a stop, makes me think it's slowly emptying the carb. I'd undo the drain screw on the bottom of the carb and watch it's flow keeps going after the bowl has emptied. If there is plenty of fuel getting to and through the carb then I'd take it off and clean it thoroughly. if there isn't a good flow I'd check it at the inlet to the carb in case it's the fuel tap/filter.

Have you tried downloading a service manual ? A manual should have the info you need.

Taking risks to save a customer money is something that needs to be discussed with the customer, and put in writing. I'm a mech, that can weld, but I'd explain the options and opt for pulling the engine.. If they want to save some labour by cutting the bike then it's their risk.

Yamaha wiring, and their ignition systems in particular, are absolutely the worst of any make I've ever looked at West. They change everything from year to year and nothing can be taken for granted. Even when the stator or cdi has the right number of wires and the same colours, it doesn't mean they are compatible. Good work doing a diagnosis and coming to the right conclusion. It's worth the time rather than throwing parts at something when it could just be a broken or shorted wire.. especially if your a mech and have to justify everything you do.. Well done.

Yup.. Do what Gw suggests, fit the old one and pull start it, or even just pull start it before removing the new starter and see if either of those things make a difference. The starter shouldn't be moving once the thumb's off the button, and it shouldn't be touching anything except the gear it engages with, and that gear shouldn't be turning because that gear engages with another gear that has the sprag clutch to only let it turn the crank but not get turned by the crank once the engine's running, so neither gear nor the starter should be turning once the thumb comes off the button. Compare the old and newstarters, and perhaps strip the brush end and body off the old starter and then fit that starter into place so you can see and turn the armature, then try turning it both ways and one way it should try to turn the engine and the other way it should only turn two gears and/but slip the sprag clutch so the engine doesn't turn.. That part #8 is the sprag clutch/one way clutch and bolts to the flywheel, Once the engine starts and the thumb's off the button none of those parts except for #8 should be turning. When the starter operates the sprag locks onto the big gear.#6 and gets turned to spin the engine via the flywheel. The idea would be to check none of those gears are turning once the engine has started. If you started the engine with the new starter in there, and the new starter was turning when it shouldn't be, it would act like a generator and put out some small voltage, up to about 6 volts probably.. You could check whether there was a small voltage on it's terminal when the engine's running which would indicate the sprag isn't doing it's job ad that the new starter is turning when the engine is running. Then to figure why the new one turns all the time when the old one didn't.

Is the noise only when the starter is operating, or all the time the engine is running ? I was presuming to start with that you meant it only made the noise when the starter was operating, which would be sort of expected with a new defective starter, but then something you said made me suspect the noise was all the time.. A new starter, good or defective, shouldn't be able to make a noise all the time the engine's running. But, if the noise is now starting to quieten, that would seem to be something to do with the starter settling in.. Perhaps the brushes weren't seated properly, though they wouldn't wear in that fast.. so who knows.. Haha.. One of life's mysteries.. a minor one .

These jap bikes are so well designed and made that they seem to go forever as far as the engines and gearboxes go. I've stripped them because people had stripped bolts trying to stop simple leaks, or ridden over a rock and holed the sump, or just to do rings and a top end, but nothing else seems to break on them or even hardly wear out.. except for brakes wheel bearings and and driveline.. I've done a lot of driveshafts and axles, and a few wheel bearings, but that was nearly always caused by riding through deep water. Use clean fuel, keep things lubed and adjusted though and they are absolutely amazing. And the places they will go !! This yamaha will probably go for years with a bit of care..

Ok, it would take a few weeks for the bush to get even slightly dry so it won't be that.. But.. are you saying it has the noise all the time it's running, or only while it's cranking ? Perhaps a video of the noise if it's all the time.. Can't think of anything to do with the starter that would cause a noise al the time..

Did the old starter crank it over.. even reluctantly.. without the noise ? It occurred to me later on in the day that they are all bearings in them now not bushes, so it shouldn't need a grease or oil. You shouldn't need to anyway, and if you do now it will void the warranty.. so probably best to just take it back if you are sure it's the starter.. There is a sprag clutch in there on the crank which could make a noise if it slipped, but then it probably wouldn't crank the engine over well anyway. If the bikes been sitting for a while not used then it's just possible that one of the gears which go between the starter and the crank could be dry. One of the gears runs on a bush I think. Perhaps empty an oilcan into the hole where the starter fits and try it again to eliminate(hopefully), anything dry in there.. The gear on a bush is the one you see that the starter engages with.

Good stuff.. Well spotted. So just a wheel bearing to go..

I'd take the starter out if it's chinese and check it was put together with grease in it.. They do sometimes seem to scimp on the simple things.. like lube !

Glad you found it.. It's amazing how sensitive some bikes with CV carbs are to their intake and air-cleaner all being just right.. Too much or too little oil on the filter can bugger them up sometimes.

Yeah as Gw suggests, jack it up and use the brake to apply some load and then put your fingers on the final drive and see if you can feel the jumping in that cover, or the rear diff.