Mech

What confusion ? Who's confused ?

Airbox hose on, needle set right, go for a drive. And remember, nice and slow up to the slope so the float bowl is full, then count the seconds till it falters at 1/2 throttle.. If we need to work on the No6 tube or the pump we will look at that next. I'll tell you how to test the pump.

You'd know if you had that No6 out, it's a long brass tube(about 30mm) and the slide needle drops down into it. It's held in by the main jet.

And 97.. to elliminate the fuel pump being the problem.. when you go for this test ride, approach the slope slowly, then accelerate and see if it starts off going ok, but then starts to loose power after a few seconds, like ten or more seconds. That should have the float bowl full at the bottom of the slope, and if it falters straight away under the load it's the mixture, but if it goes for that few seconds then starts to falter, it's probably because the fuel level is falling in the bowl.. That will mean bad pump or filter in the tap or bad tap.

And 97, just to save me a lot of reading.. When you had that carb apart and were cleaning it, did you take the emulsion tube out and clean it's tiny holes in the side of it, about half way up the tube ? There will be two or more holes.. Part six in this picture..

The important thing Gw is to make sure you have all the jets and needle and settings right for one of the models.. The problem is not so much having the wrong set of jets, it's having muddled sets of jets. You have to have the idle air jet, idle fuel jet, and the idle screw all right for one model, and then the main air jet, main fuel jet, emulsion tube, slide and needle, all right for that same model

And a quick search through a few different models, all your year has four different main jets listed for that carb..

Before you put the needle back in see if it has some numbers on it.. let me know what they are. Yup I saw about the float height.. If it's as the book says it won't be the problem.

And unless you bought that kit off suzuki, I wouldn't trust it to have the right jets or needle .. not one bit. In your year alone there are two differently set up carbs just in my market.. The NZ market.. There are canadian, euro, american, jap, swedish markets.. and probably variations within those markets. The problem is not with the idle circuit or the idle mixture screw. It's the slide, or the needle.. if the float level is set right.. Put the airbox hose on, set the needle clip to the center and go have a try.. Tell me what happens exactly, how it differs from now, and I'll tell you what to do next.

No, that version just has some plastic spacers and perhaps a metal one, all fitted onto the needle. The needle holds the needle from jumping around once the cap is screwed down. Ok.. Well that's what I've been trying to find out for days.. haha.. It's almost certain to be a lean mixture. And the further you open the throttle the worse the back-firing and the slower, or more gutless it gets right ? So put the airbox hose back on, set that needle clip to the middle position and go see if it improves. I don't suppose by any chance you happened to take note of what the jet sizes were when you had it apart did you.. so I can check in the book what it's meant to be.. Only the main jet is all we need..

So.. when you are trying to go up this incline, does it backfire into the air-box when you open the throttle too far ? Or does it just fade out of power without the backfiring ?

Yeah, and the spring goes down into the slide and presses the needle down into the slide so the needle can't jump up and down...

Oh actually, that spring you are holding will be the 10mm one.. so you have a steel cover.. Ok, so that spring goes down into the needle tower and is meant to keep the needle down.

Well I must have missed that bit about the incline.. There are two versions of carb, one with a steel cover and one plastic.. one has a diaphragm spring about 10mm diameter and the other diaphragm spring is about 14mm diameter. I'm thinking yours is the plastic cap and the 14mm spring, and on that one there is a tower that comes up around the needle that has four slots in it.. Is that right ?

Without the O ring the needle jumps up and down and fuel gets chucked in there in a completely random fashion, and generally far too much of it.. And that doesn't look like any part I've ever seen in there for the job. It normally is about 20 mm long, has an O ring on the bottom then a flange and a flatter part that's serrated so it can be grabbed with a pair of pliers.. Find a bit of rubber hose about 6mm diameter and use that to jamb down on top or that spring temporarily and see if that fixes it. If it's held down by the spring it will move up, but against the spring pressure, not completely freely.

Yup well it flashes a code, a two digit code. Count the flashes and let me know what it is and I'll look in the book.. But you really need to look at the manual so you can follow what I'm describing. The code is probably made up of long and short flashes. Longs are tens and the shorts and ones. So long short is 11 long long short is 21.. I think that's how it will be.

I don't know, but it should be readily accessible, and I'd have thought quite obvious.. You should download a pdf service manual, or an owners manual and it will tell you where everything is. Thgere's probably a manual in this site.. Up the top of the home page on the right.. Manuals

So it won't even move ? Not even if you just give it minimum throttle ? Is it that bad with the carb to airbox hose on as well ? The CV carbs are fussy about their air-cleaners. If it idles nicely, then it should run up to about 1/4 throttle, and you should be able to get it moving like that.

From 1/4 up the fuel is being metered by the slide needle, which is easily accessed, So I'd take the top off and raise the needle a notch as my first step.

I've only heard of limp mode in EFI.. It will need a computer of some sort to have a limp mode..

Your slide needle should be sprung loaded downwards. There's meant to be a small spring pushing it down, and the spring is held down by a plastic bit with an O ring on it. The O ring is all that holds the plastic bit from pushing up. If the O ring isn't on the plastic bit, or if it's old and hard, or if the plastic bit can be pushed up and out of place by you pushing the needle up slightly against the spring, but without actually pushing the plastic directly with the needle, they you should change the O ring. The needles always wobble around sideways in the slide, that's ok.

I'd put the inlet hose back on and ride the bike to test it 97.. If it backfires then it will be as I say, if it doesn't then you should check the valve clearance and even possibly the valve timing, but a lot of single cylinder engines puff out backwards like that and I wouldn't consider that a major symptom on it's own.

Good explanation Dave. It's a bit hard to differentiate, and detonation can cause rod knock anyway. If you have a bad rod bearing it might make noise without the detonation though when the engine is under a load. If you have a manual shift bike you can test the rod bearings to a degree by putting the bike into gear with the brakes on hard, and keep your toe holding the shift lever down till you've given the engine enough revs to lock up the centrifugal clutch, then gently let your toe up till the shift clutch starts to engage and put a load on the engine. If the rod bearing is bad you might hear a knocking sound.

This covers most cases of backfiring, and by that I mean loud pops or bangs, not the un-burnt fuel spitting out the back of the carb that's sometimes observed. Ok, so there are two types of what people describe as backfiring, one sort is when it backfires out the exhaust, and the other is when it backfires into the carb and airbox. So, backfires out the exhaust happen under two different circumstances. First is as you are riding along, the bikes going fine, but when you are going at a steady speed or throttling off it makes a loud boom out the exhaust... and that sort is caused mainly by an exhaust leak up near the head or front pipe. It can also be caused by a lean mixture, or a rich mixture, but either way, the bike is generally going fairly well. The other circumstance is the bike is not going fine, it's missing, and then there is a loud boom out the exhaust... that is nearly always caused by an electrical miss... bad plug or coil something like that. Then there is the backfire into the carb. This generally happens when the bikes being ridden and the throttle is open. It's not the fairly common, occasional pop as the bike is being started or turned off. This backfiring is because the incoming mixture is getting ignited. There are a few possible reasons for that. It can ignite because the valve timing is out, and then they don't idle so good, and they are down or torque when you drive them. Or, the incoming mixture is ignited by carbon build up, or a real hot spark-plug tip, both of which needs the engine to run for a while till it's good and hot. Or, the incoming fuel gets ignited by un-burnt gases caused by real late ignition timing, which is super rare these days. That also makes them gutless. Or because the mixture is still in there burning because it was so lean on the last firing. That is the most common cause by far. There is another cause of burning still going on in there when the new charge arrives and that's raw fuel deposited on the cool head surface and smoldering away, but that doesn't get caused by a rich mixture alone. Iif the properly atomised fuel mixture was that rich it would be spewing black smoke, but it can be caused by badly atomised fuel getting in there in big globs. That can be because the slide needle is loose and jumping up and down, a vacuum hose to an auto-fueltap or a vacuum fuel pump is sucking in fuel, something like that. Hope that points you in the right direction when you are trying to figure a problem, or describing a symptom in here. Remember, there are symptoms, and there are circumstances relating to the symptom.. Take note of both and it helps mightily when you are seeking help or diagnosing the problem, and that applies to all problems, not just backfires..

Check if you have power at that fuse No3.. If not then check that connector near the battery isn't apart, or dirty. Ha.. Snap !