Mech

Well.. lean mixture can cause backfires into the carb. A blocked exhaust could possibly do it but it would probably have some subtle symptoms as you tried to ride it.. It would start to go sluggish before the backfires started. What make and model is this thing .. just so we know what sort of carb it will have.

The extra washer won't have made any difference, the clutches are already pulled back by the nut, and the nut clears the case, and the depth of the dowels is more than the thickness of a washer. Does it feel locked up if the cover is off ? Is the cover touching one of the clutches , stopping it from turning ? I take it that it turns when it's not in gear, so it has to be that shift clutch touching somewhere I would be pretty sure. It should all be back as it was after the first assembly, with the sprag allowing it to turn one way but not the other depending whether you are in forwards or reverse. You could look at the gear between the centrifugal and the shift clutches and see if they look aligned, that might reveal something. Check the shift clutches mechanism is all in it's proper place..

Gw, I owe you an apology.. for casting aspersions about your skills as a mechanic. I'm sorry. It was an unworthy suggestion. I wandered off last night wondering how that bolt could have got broken and then it came to me.. The last owners had strained it cranking that cover down as they had. It's obvious you are a very careful and competent mech and I should have though before I spoke. Even if they had bottomed out they wouldn't break at that torque. It's quite likely that all those bolts are suspect. If you do take the cover back off it would be a good idea to measure them for stretch. Or inspect them for "waisting", getting skinny in the shank.The parts list might say how long they are meant to be.

My sons always say "Oh I'm not sure about that dad", and I always tell them, "yes, but I am".

All else being equal, there are always two that are a little longer so they get to the bottom of the dowel holes.. It's the norm. The easiest way to be sure you get them in the right places is to fit the case up and then slide the bolts in till they touch, then check they all have the same eight mills proud. The last owner might have muddled or swapped some..

Have you ever noticed that anything that buggers up the vacuum, like air leaks or tight valves, seems to effect them more at idle than when they are revved up ?

Could you have got the wrong bolt , or two, in the wrong holes ? That would do it and sounds a bit like it the way you say you got a bit of warning.. Bottoming out I'd suspect.. The dowelled holes need longer bolts. I always poke all the bolts into the cases first with the case in place and check they all have the same ten mills of bolt showing. Might have been needing a break and a coffee Gw.. If they did bottom out then they will be tight in the bottom of the holes and won't come out easy, but if they were buggered bolts and snapped suddenly then they will unwind out of the threads easily. Perhaps even a screwdriver tapped into the end of them if they are soft bolts, which the 8mm hex head ones often are. And the wrench won't be so far out as to break them.. Push in button is it ? Not a giving at torque type .. I've been caught out with low torques with them, they go off before you are paying attention and then you carry on waiting for the click. That's where that loctite is so good.. Easy to clean off and just a few cents worth of goo from on the shelf and it's all redone..

Bugger about the bolt. Good stuff otherwise.. I don't think I'm as patient as you. I'm a patient mechanic but I'd be busting to start that bad boy up.. haha.

Mmm well, sucking on a pipe is easier than adjusting the valves or swapping heads.

I agree Gw, but if it has good spark then that's just an anomaly to be addressed next.

97.. If you don't have a timing light try getting another sparkplug and fitting it to the lead then resting it on the fitted sparkplug so the spark will go through the first plug and then down through the fitted one. The one on the lead can't touch the engine, only the end of fitted plug. You might have to hold it there by the lead. If you have a good spark it will go through two plugs inline. Then watch the one you can see and make sure the spark isn't dying before the crank stops turning. That will eliminate electrical problems. Then concentrate on the fuel.. And yet they do Randy. They can.

If it has a hole in a diaphragm and it's sucking fuel in it won't be running lean And it might have more than one problem.. Best illuminate one possible thing at a time and be methodical about it. Start with the simplest. Ha.. eliminate

If you have a timing light put it on and check the spark isn't dying or getting intermittent.. Then you know to concentrate on the fuel.

Just suck on the two vacuum hoses carefully to see if you can suck fuel through them.. It would mean a hole in a diaphragm if you can. And the intermittent readings from the gauge is probably because your gauge only takes a reading a few times a second, so you are sometimes getting it at the top of the sine wave and sometimes not.

It might pay to check the fuel pump and for fuel in the vacuum hose to the tap.

Fair enough Mod... I'd already stopped.

Are you aure you sparkplug and coil are good ? It's not good enough just looking at the sparkpklug when it's out and sparking, they can fail under load. You also need a good battery and it's very likely here that you more than one fault. Do you have a timing light ? Put it on and watch it while the bike starts to faulter. If the spark get intermittent then the spark is breaking down.. But that doesn't test the spark plug.

Put tyre slime in them... It fixes slow leaks and prevents new ones. If it is the beads leaking you'll need to pull the wheels and lay them on the side to get the slime there, but if it's prickles in the tryes just riding it will seal them.. I love the stuff. I put it in as a preventative. Haha.. I'm a mech Gw.. we never do anything to our machines unless we have to..

Go to an auto parts store with a sample and they might be able to match one for you. They have catalogues with all the dimensions and concertina profiles and all that..

You need a good battery in it 97. Try switching the headlights on and see if it makes a difference.. The lights will provide the load the battery isn't.

All good Bro. I'm like you and have a wide skill base, all practical stuff, and work hard(well I used to), and I was invited to settle and live on someone else's land after I'd been living on my yacht for three years. They even offered to subdivide but I didn't need that so I just built a cabin and worked there helping out on the farm and mechanicing. Get a bus and go.. you'll fit in. Land.. It's not so much the distance from town, though the more remote the cheaper, but the ten to twenty acre blocks are the most popular with the lifestylers. I needed a through road so people could access me easily, and we found a semi cut over forest block, on a main through road about twenty minutes out of a small town. I'd had interest in forestry and knew the industry went in cycles, and that the loggers and truckers would be back in a few years. As it happened, about two years after moving into our new place the market came good and we sold most of the remaining trees for $38,000.. The land cost $25,000. Hope it goes as well for you. Get into the community, talk to people, take advice and offers of help. Be helpful.

Yeah well we'll let people decide that for themselves. You "logic", if that's what you call it, goes something like this.. R I skidded on a slippery road and had a crash once. M Perhaps you dozed off, or were going too fast, or your tyres needed attention. R No, only slippery roads cause crashes. Nothing else but slipper roads cause crashes, and here's a whole heap of newspaper clippings to prove it. M But Randy, I could find you a whole lot of newspaper clippings showing that speed causes crashes too. People should slow down and make sure they aren't tired and check their tyres. Every police department says to slow down and check your tyres. It's well known that speed can cause crashes. R No, that's bad advice.. People shouldn't slow down or check their tyres. That's bad advice Mech. Yes sir.. Like you say Randy, the internet is a big place and we can't hide from our posts.. I know when you got into quads, I know when you first had a regulation problem, I seen you asking for help to diagnose it.. But, like you also say, you just come in here to argue.. And like I keep saying, I come in here to help people, and you Randy, can't be helped.. You carry on, someone might feel like a stupid and pointless argument, but I have trouble lowering myself to your level of stupid.. I can't oblige you.

Yeah that's all as it should be. It had no drag in low/high because it wasn't in any gear. Ha.. looks good.

Bit late now but engineering supply places have stocks of shim washers, in different sizes and thickness. Why not reverse yet ? If you put it in reverse and turn the wheels you'll be able to tell if it's forwards or reverse by the way the sprag/over-run clutch works. In forwards you can't push it forwards, in reverse you can't push it backwards..

Er.. What's that little tick under your name tag there about Randy, and why do I have twenty-one under my name ? I saw you going looking, clutching at straws in the old threads.. You're an idiot Randy and you just don't want to learn..