Mech

Depends on the type of carby and that depends on what year the bike is.. There's probably a service manual for it in the manuals section...

Or there's an O ring between the float needle's seat and the carb body that's leaking. Or the float needle's being held open by a piece of fluff or dirt.

View File Hisun HS5DUTV-2 EV SECTOR E1 Service manual The first twenty something pages are garbled, but they are nothing important. Submitter Mech Submitted 04/17/2023 Category Hisun UTV  

View File Hisun Sector 550 Service manual The first twenty something pages are garbled.. It's nothing important though. Submitter Mech Submitted 04/17/2023 Category Hisun UTV  

Well... you've got time for a beer then. That brass barrel, (and lots of other small parts), get dropped end up either on top of the motor near the starter, or in the cooling fins, or down under the motor on the crash plate.. You might find it in one of those places.

Good work Ford. Glad you got to the bottom of it.

Onya Gw..

There's the pilot/mixture screw, and there's the idle speed screw. The speed screw is on the side of the carb. The mixture screw makes it leaner when it's wound in(and richer out), and the speed screw opens the throttle when it's wound in. Wind the speed screw in until the bike will keep running, it might have to be wound in quite a long way but eventually the bike should stay running, if it won't run with the speed screw right in then the carby is dirty or there is an air leak into the manifold or a tight valve or some other problem. If the bike will stay running then try adjusting the mixture screw trying to get it to run faster. Wind it in and out a bit and see which way it likes best, then keep winding it that way. If the revs build up(and they should), then slow it down with the speed screw, then go back to adjusting the mixture screw in and out till it's revs get as high as possible, then slow it down and adjust the mixture again.. Eventually it should end up ticking away slowly but evenly, and then you use the speed screw to get it up slightly to the recommended slightly fast idle. It doesn't need to be taken down to the very slowest possible as you do the mixture, but as slow as is possible to have a steady idle. If it won't idle nicely after an adjustment then there's a problem and so I'd recommend pulling the carb and stripping it right down and cleaning and inspecting every jet and drilling and while it's off check the inlet for possible air leaks. Some have rubber inlets that split, and some have a gasket and some have an O ring, and some have an O ring and a gasket. If all that still doesn't get it idling nicely then checked for blocked breather hoses on the carb, tight valves, or a spark plug with too much gap. And no, there is no "minimum idle gas" and then the idle speed screw adding to it. If you wind the idle speed screw right out the engine will stop.

View File Hisun Tactic 550 EFI Owners manual. Hisun Tactic 550 EFI Owners manual. Submitter Mech Submitted 04/16/2023 Category Hisun ATV  

View File Hisun Tactic 550 EFI Service Manual Hisun Tactic 550 EFI Service manual. Submitter Mech Submitted 04/16/2023 Category Hisun ATV  

Yes you can check the stator for an out put AC voltage. you test the three stator wires two at a time, same as the resistance check, except while cranking over it should put out an AC voltage of somewhere between .. er.. about eighty to two-hundred is common, but allowing for a slow crank.. maybe more than twenty volts at least I should think would mean it's working. You had spark though, and stators don't generally get intermittent. Wiring on the bike or faulty switches play up intermittently sometimes.. Have you checked both the switches are working properly and every time ? Have you checked over the wiring loom looking for chafed insulation ? Around the steering head where the wires move, and down near the motor where there are dangling wires are common places, but anywhere can chafe through after a long life. Is the spark plug getting wet with fuel when you try to start it ? Are you sure that wetness hasn't fouled the plug/plugs ? Have you tried burning a plug clean over a butane flame and then putting it in still hot and trying to start the bike ? You did say early on that if you started it straight off with no checking for spark that it started..If it can be started the spark is probably going to be fine. I still suspect your plugs.... Plug and bad carby settings perhaps combining to flood the engine and foul the plug if it's not started straight away following some certain procedure..

Yeah ohms gauges are tricky things. The whole concept of resistance, and it's ramification, is a tricky thing.. If there is a total open circuit the gauge will read with some text mostly, something like OC or an infinity symbol( a short wavy line). If the gauge is on the wrong setting then yeah, it won't give a true figure, and it might show "0", but that's not the same as infinity. If it shows an infinity symbol then there's an open circuit, if it shows any other figure, even a zero, it's a reading. A lot of people get tricked into thinking a zero reading is the same as an open circuit.. it's not.

With this being a cdi system, the increase in spark while winding it over with a drill is probably not so much to do with the increase in speed. It could play some small part but cdi systems throw very consistent sparks at any rev. I think a more likely explanation is that it has a bad earth connection somewhere. If the earth between the frame(or engine) and the battery was poor, and only letting just barely enough power through, then, when you use the starter it would start putting it's earth current through that bad connection and there might not be enough flow to allow the coil to earth itself fully at the same time. If not a bad earth then a bad power supply to the cdi unit (if that cdi has a 12v feed in). A bad power supply will work much the same way. Another possibility is that the ac output of the stator is a bit weak, possibly because the magnets have got weak.. Have you checked the stator resistance and ac output voltage ?

The choke should be up and forwards for warm running. You should change the fuel. Stale fuel causes all sorts of problems. It probably won't run right without the air filter. The brass barrel is about six mills long and six mills round and it's drilled and slotted to accommodate the cable, and it goes into the carb's cam shaped bit on the side, in a big hole near the back. I think it's part 39 in this parts diagram.. https://www.mickhone.com.au/partFinder/fiche/suzuki/2001/lt-f300f/carburetor#next

Yes.. the pilot screw is mixture.

There's a little brass barrel missing off the end of the throttle cable. It goes into the throttle cam. If those things run out of fuel they need a lot of priming unless you fill them right up nearly.. They can be primed, and the pump tested, by sucking on the vacuum hose going to the fuel pump. The pump relies on fluctuations so to get the pump to work you have to suck then release then suck and release and on and on. The fuel tap is controlled by vacuum. It has two positions where the fuel will only flow if vacuum is applied to the tap, and a center position where the fuel flows full time.. There is no off position. The center position is called "prime" and is for priming the carb if it's been empty. To test the pump, or aid the priming if you don't want to strain the battery, put the tap to prime and suck repeatedly on the vacuum hose off the carby. If you take the fuel hose off the carb and lay it on it's side and then suck on the vacuum hose to the pump, it should pump out fuel. Suck on the vacuum about three times till there is a strong vacuum built up, then release it and the fuel hose should push out a slug of fuel the full diameter of the hose and about ten mills long. It needs to be on prime to do that.. Don't leave it on prime over night or it will very likely fill the sump with fuel..

You have to be careful swapping jets. Not all jets use the same threads or size classification. Not all cheap jets are accurate. at all. Even if the old jets do fit a new aftermarket carb, the idle mixture screw may not.. It may have different threads, or have a different tapered or diameter pin on it's end. If you do buy a cheap aftermarket carb it will always run better if it's tuned to suit your bike and climate, fuel, altitude etc. The trouble is that if you want to buy different jets, or slide needle, you can never be sure the jets are the thread you need, or are going to be that 5 up from the jet you are holding in your hand.

Well that last test with a non resistor plug sounds like the plug is crook. The thin and purple spark sounds normal for a resistor HT. You probably don't need a resistor plug and cap, one alone should stop radio and tv interference, and the bike will run just fine with or without any resistor anywhere in the HT. Plug caps can get high resistance and not let any spark through, or they can develop cracks or carbon tracks across the inside or outside that short the spark to ground. Even when the caps resistance is correct by the book, they can still leak spark away. The rubber boots can get conductive also.. Sparks don't like jumping under compression. It takes only a bit of air pressure to make it really hard for a spark to jump. Just because a plug is sparking while it's sitting against the head, it doesn't mean it's going to once it's in place and under compression. Compression will make dirty plugs short, plugs with wide gaps not spark, caps with high resistance or tracks to not spark or short to earth. Always suspect spark plugs.. They can get fouled in a few cranks or kicks over.. Spark plugs can be dead right out of the packet (rarely), and/or they can be fouled before the bike even starts if the fuel is old and stale. Certain oils will also foul plugs really quickly. A new good plug though, in a bike with stale fuel, can get the plug fouled with just a few muffled puffs out the exhaust as the stale old fuel tries to burn, but with the engine never even starting up.

It's important to have the idle speed screw set as slow as possible while you are adjusting the idle mixture. Then after you have the idle mixture to the best setting you speed the idle up slightly to specs, or what suits you. If you have the idle speed screw wound in too far when you are adjusting the idle mixture it is adjusting the mixture with extra air being mixed in that is not intended to be there, and that causes a flat spot/hesitancy as you open the throttle. The recommended procedure is set it to a slow speed with the speed screw and adjust the mixture, then slow it again and readjust the mixture, and keep doing that till it's slow and the mixture screw is halfway between just starting to slow from being too rich, and just starting to slow from being too lean. Then wind the speed screw in if needed. Don't readjust the mixture screw. If it doesn't like being sped up, or if it has a flat spot, there is a problem with other systems in the carb that need cleaning or adjusting. Most bikes the idle mixture screw is quite sensitive, and a half turn can go from rich to lean. If it takes more than about a full turn, or if the mixture screw seems to need winding all in one direction without ever making it too rich or lean as we would expect, then there is a problem in the idle mixture jets or idle speed setting.

Look in this link and you will see down a bit there is a list of what other models that part fits, and what part number they use for that model if it's different to your part number. https://www.partzilla.com/product/yamaha/BW4-E7611-00-00?ref=e02441505aa7df3633c275831c253fddf4a57e45 Choose your parts, and check what other models the part fits with this link.. https://www.partzilla.com/catalog/yamaha/atv/2018/yfz50-yfz05yyxjl/clutch

If it's a two wheeler, teach them how to fall off it, without getting hurt. They are going to fall off and most injuries are from still being attached to the bike at the point of impact. They need to practice falling off till their actions are reflex. It's easy to do and it lasts a lifetime. Start by making them lay it down while braking with the rear brake. Find some bit of mud or wet grass and make them speed along to some line then jamb the rear brake hard on.. make it a competition to do the longest skid to start with and they will practicing it for hours. They'll start laying the bike down on it's side and that teaches them to pull their leg out from under it so they can roll away. Make them practice skidding the bike to a stop on it's slide. Do it from higher and higher speeds. Train it as a reflex. When they always pull their leg up out of harms way, when it's a reflex to them, then find some flat grass or mud and hose it down and teach them to do donuts, going round and around with one foot on the ground and the bike leaned way over. They love that. They'll soon be doing it with both feet on the pegs(especially when they see Dad can't do it). That teaches them all about traction and grip and balance and throttle control. Once they can do that, you can introduce a higher speed loop they can hoon around sliding out and getting the front wheel crossed up on. Get them good and used to laying the bike down, and getting their leg out from under the bike. That's the most dangerous thing.. people that don't thin of pulling their leg out, don't think of rolling off backwards or sliding it to a near stop then jumping before the big crash either.. haha.. People that do have their leg pulled up, can do either. Teach them to have fun, to drop their bike, to get a few scrapes.. But teach them their bodies are more important than any bike and too be ready to jump off when needed.