Mech

The one for your year.. haha. They come in ranges of years, about four years is common, so if the manual you look at isn't the right one, try another a few years older or earlier.

The load backfire makes me thing the timing is out, which could be caused by dirt or water in a plug down near the engine where the stator wires come out. Is the backfire out of the exhaust or the inlet ? If it's the inlet then it suggests a weak mixture. Exhaust it could be an intermittent spark or a mistimed spark.. I'd have a good look at the plug where the stator wires come out for intermittent connections down there(just because it's likely near where you were working). It must presumably be getting fuel for the exhaust to smell of it. Did you work on anything else while diagnosing the starter ? Efi systems depend on the crank and air flow sensors, and those sensors don't read very accurately at cranking speeds or voltages, so they generally feed a signal into the control unit telling it that it's being cranked. That signal is meant to fix the mixture and timing at figures that will make it start. If the efi isn't getting the start signal the timing and mixture could be all over the place. It would be a good idea to get a manual and check the start signal is getting into the efi control unit. The efi also will have several power in wires, and several earths, you should check all the earths on the bike and the several power in wires to the efi are all good.

I'd try a new spark plug first, and then completely strip and clean the original carby, check for air leaks at the manifold, or any small vacuum hoses, and for blockages in breather pipes. If the original carb used to go ok, then that's the one I'd use. The other one might have a fault or not be setup for that bike. You are introducing uncertainty by fitting another carb.. Strip and clean the original really thoroughly. The symptom you have sounds like the slide needle needs moving up, but I would check everything else before I did that because they don't usually adjust themselves.. It's more likely you have a low float level, a blocked jet, or the emulsion tube is blocked. The emulsion tube is the brass tube that goes up from the main jet to the slide needle. You need to take that out and clean the small holes in the side of it, and clean the drilling it fits into. Blow out the air jet near the aircleaner end that feeds air to that emulsion tube. Check the diaphragm on the slide for small splits too, they might only show up when the diaphragm is stretched. Check plenty of fuel is getting into the carb by undoing the drain screw and watching the fuel flows readily.

So was it going ok before the new starter was fitted ? Do you have any ideas about how the magnets broke ? How long has it been siting since the last run ? Have you looked around near where you were working on the starter looking for disturbed wires/plugs or knocked off vacuum hoses ? Are you sure the fuel is fresh ? Do you have a timing light to check the ignition timing ?

I don't know those things but if it's a two stroke I'd pull the exhaust off and have a look in through the exhaust port at the piston.. looking for scoring or signs of overheating seizing. That might be the cause of your noise. I'd also undo the drain screw on the bottom of the carby and check the fuel flow is adequate. If there is plenty of fuel getting through and the piston looks ok, then I'd take the carb off again and strip it entirely and clean all it's jets and drillings, and check the manifold for splits if it's a rubber one, or missing gaskets or O rings if it's a metal manifold.

It's late afternoon in New Zealand and a merry christmas to you all. We don't do the present thing here, but I just got back from a very pleasant afternoon of three generations and many branched family get-together. they were just lighting the barbecue as I left, I know it's winter over there but may your gatherings be as warm as the one I had. And I got there and back on a quad.. haha. if that makes it better(and it does)..

Thank you Bunchy, and the same to you and yours. Merry christmas everyone..

Thanks Krominator, and to you and yours too. Yeah the bike ones are dearer than auto ones.. If a thermostat is going to cause an airlock in the system, then the thermostat for that machine has a small hole it it to let the air out. The hole needs to be at the top. Other than that though the cooling systems these days are generally designed to self bleed.. But sometimes on a bike that might require a small hose from the top of the motor going straight up to the radiator. If that hose gets blocked or kinked it can cause an air lock problem.. Sometimes some of the radiator hoses look like if they were routed wrong it could cause an air lock too.

Yeah it would be real handy for things that have to be pressed hard or far to fail.. I generally only use the light at an idle or a few revs.. I'm amazed I've never seen one of those before. Good tool there folks.. and cheap. You all should get one..

That's a handy tool alright Tiha.. I use a timing light for the same purpose but you can't ride around with the timing light..

Yeah well don't go ripping the engine apart just yet.. It will be carby or charging.. Check the voltage goes up to about 13.6 or 14.4 after a while and no higher. Check the wiring by wriggling it and inspecting it for chafing.

Well.. you say it started having starting issues and so you cleaned the carby, but after that it's not making it up hills. which sounds like a different problem, and, if it only started after you'd worked on the carby, sounds like something you've done. Then you put anther carby on and it's got the same issue, but which issue, the hard starting or the no power ? And are you really sure the new carby is good, like, did you take it off a running bike to try ? It is possible you just need to clean one of the carbies really carefully and it will be fine.. It's also possible it's not getting enough fuel into the carby.. a dirty filter in the tank perhaps. It's also possible the motor has low compression, worn rings or valves not sealing for some reason.. Perhaps the valves need adjusting. My advice would be to check the compression, check there is plenty of fuel getting into the float bowl, which you can check by undoing the drain screw and watching to see it keeps flowing at a good rate, then I think you should clean and set up the original carby again.. When you clean the carby you need to strip it right down, take the float needle's seat out, and the emulsifying tube that goes from the main jet up to the slide's needle. Take all the jets out and clean them carefully. Blow through the air jets in the air intake side of the carby from the aircleaner side. Clean up the chamber the emulsifying tube goes in. Blow through all the places where fuel jets fit. When you have it apart, check where it fits onto the manifold that there are no air leaks. It will either be a rubber manifold, check that for splits, or it will be bolt on, check that has an O ring and/or gasket. Once it's back together warm it up and adjust the idle speed and mixture to the best slowest idle possible.. then take it for a test ride.. On a test ride, be observant about how it goes, how much throttle you are giving it when any problems start to manifest, and how it responds if you ease the throttle off slightly. Hopefully after that it will be cured. but if not then report back and we will see what else we can figure.. but you need to be methodical about the carby work, and when you are riding and observing it..

You need to check the charging, that it does charge and that it regulates. Check all the wiring between the battery and the regulator, and the earths, for broken wires that loose contact intermittently, which you can do by letting it idle and wriggling wires listening for changes or observing changes in the battery voltage, and you need to check the wires don't have bad/dirty contacts or resistance in them. If the regulator is defective causing the running problem, it will be consistent. It won't matter whether it's in gear or driving, or sitting stationary running, when you rev it up the motor will either strain or start to cut in and out. Since it's only doing this when you try to ride it, I'd suspect a wire problem.

Ok, sounds like you have a good handle on it. I'm just generalising.. Putting thoughts out for your consideration. Yeah that low max compression probably is to check the decomp against. It's a 10:1 compression ratio so should have heaps of pressure running. I agree with you that it seems unlikely that the eps would cause the hard starting, but I wouldn't be surprised if the hard starting problem might set the eps codes. If the starter is straining it could be lowering the battery voltage too much momentarily and setting one of those codes. So.. on cars those isc get gummed up. That could contribute to the hard start and straining starter. If there are no engine codes set then it's probably not an electrical problem, so a stuck actuator would be a suspect. And both those codes do relate to the eps ? The book I had didn't have the eps in it. From other reading though I'm pretty sure the eps and the ecu communicate. An electrical fault in one system might upset the other. If getting it to idle doesn't fix things, then as a general rule, if we have problems in two different systems we should always look for things in common, such as power supplies or earths. In cars it's a common circumstance that no codes get set for bad power supplies or bad earths, the modules just aren't set to detect or code that. In older cars, if there's a problem and no codes get set we get told to check for stuck or out of range components or bad earth/power wires. It's also pretty vital that after or during testing of components we test the wiring too. The easiest and quickest way to do that is to test from the control module's plug to the sensor/actuator involved and back to the module (if that's how the circuit goes). If you've checked all the sensors and actuators and the wiring, most manuals say to try a new or known good module. Perhaps you could borrow one off a buddy's bike or fit the suspect module to another bike. Hopefully though, the eps will all be a false alarm. Feel free to run any other thoughts past me. Sometimes just talking it through helps.

I think though that computer only sets codes for electrical problems, like broken wires, and doesn't come to conclusions such as the isc is gummed up.. It might, but I doubt it.. I'd clean the isc to be sure, because they do get gummed up, but then I'd check the isc valve electrically. You need to trace or read a wiring diagram and find the isc wires at the control unit, then check for continuity from there to the isc, and back again if possible all in one continuity test, so that you will have checked the two wires and the plug at each end and that it's contacting the isc properly..

Yup, seventy pounds and they are hard to start.. Trickily though, the service manual says seventy something pounds max as the compression pressure.. but then right there it also says it's ten to one compression ratio.. Perhaps the max is meant to be 175, or, 75 is the minimum not maximum.. which would make more sense.. to quote a minimum pressure.. But Sha.. regardless... it said one of those trouble codes was the idle speed control, and that could be all the problem is.. I couldn't find the other code in the book I was reading, but it might be a problem caused by the isc.. it might come right once the bike idles again.. They make spray in a can for cleaning idle speed controls.. I've never used it but it might be worth trying that if you don't fancy taking the valve off and cleaning it.

There's a manual in the service manuals section of this site.. It's called "1999-2000 service manual".. Up the top, "more", "atv service manuals", half way down the new page that opens you choose your make.. Page 602 in the manual....

I had a read.. I'm assuming this is a polaris sort 400.. You might have a switch in the throttle on the bars that is playing up, or the throttle cable may be adjusted wrong. To test those and the limiter control unit they say to disconnect the black kill wire from the cdi unit.. You should geta a service manual and have a read..

What make of bike is this Big ? Do you know what the over-ride button is meant to be over-riding ? It could be a start inhibit over-ride... so it can start in gear ? And.. have you checked what the spark-plug is like, checked the exhaust isn't blocked, checked the fuel flow, or tried cleaning the carby ? Have you checked the charging system is charging and regulating ? Any of those things could give the no rev symptoms.

I looked in a manual and it says the code 54 is for the idle speed control valve.. That probably needs a clean..

The wiring plug and pins/terminals should be availiable though from an electrical supply place. All vehicles use standard design plugs and terminals. The various designs have names.. If you identify the design of plastic plug, then you will find new terminals for it easily enough I would think. The old pins will come out of the plastic once you have released the small locking clip inside it. To see various designs of plug and pin you could look in RS Online... Visually identify the plastic plug and then look at what terminals fit it.. Industrial Solutions | RS formerly known as RS Components (rs-online.com) Electronics components, power and connectors... Or post a picture in the forum and I or someone may recognise it..

I'm not familiar with those bikes but if the manual says they don't need bleeding then presumably not.. In some vehicles though the air is bled back to the header tank by a small diameter hose, and those can get blocked, kinked or misrouted so there is an air-lock and can sometimes mean air doesn't get out.

Have you checked for an air leak into the manifold? Perhaps a vacuum hose or charcoal canister if it has one? I'd check the manual's wiring diagram and see if there is a starter feed into the ecu. A lot of things tell the ecu they are cranking to set the timing and fuel to fixed values because the sensors aren't accurate at cranking speeds and voltages. A lack of that feed could cause it to be trying to start with too much advance or a lean mixture. The ecu and the eps computers are interconnected so the eps codes might be interfering with the engine, or the engine problem might be causing the eps codes. Both problems need fixing. I'd do a standard tune, check the filters, valve clearances, sparkplugs, ignition timing, vacuum hoses, then clear all the trouble codes and test it again and then look into the eps codes. It might pay to check the earths and the power wires going into the ecu and the eps control unit. There are probably more than one power and more than one earth going into each. Earths and power are both common to both circuits... Also.. that figure of 75 is too low for compression.. it's probably meant to be 175..

Sounds good to me.. You wouldn't want your boot/sock/jeans getting caught in that crank fitting.

Ha good onya mate. If those pull starts are like a suzuki the nut in the middle that turns, will be seized onto a shaft that comes up through everything that it all spins on. That shaft is meant to be attached to the tin cover. I'd probably try splitting the nut open with a chisel and anvil till it turned or split right off, and then brazing the shaft back onto the cover.