Mech

If the oil made no difference then it points to the valves.. Sticky in the guides, badly worn cam, play in the cam bearings, play in the timing chain, carboned up valve heads(except that doesn't happen these days), something blocking the exhaust, like a flap of rusty pipe inside, It is sort of normal for compression readings to climb on each compression stroke, up to about four or maybe five strokes, then after that you might get an extra five pounds if you are lucky.. But you've done plenty of tests, and know that one right, and this is different in that it doesn't build up if you just keep your finger on the button. You have to let it get another breath between cranks.. Right ? I'm just trying to get this clear.. Not enough lift on the inlet valve.. ??

A compression that climbed over a succession of compression strokes used to be attributed to weak rings. If you have a vacuum gauge you could check the readings.. If you put about a teaspoon of engine oil down the sparkplug hole then check the compression it should go up quite a lot.. Sticky or leaking valves don't get improved by oil down the bore, rings do.

It's worth trying to get that choke plunger out and saving the cable.. and carby If you disconnect the cable at the handlebars it will give you a bit of extra cable which will let you slide the rubber cap and plastic nut along so you can see down into the choke slide. If you use a tiny screwdriver very carefully you might get that plunger to rotate, then pull out. The plungers are soft and distort out of shape easily so you need a real tiny screwdriver that will go down deep into the slot in the plunger. If you lever near the top the plunger will flare out a little.. but then you can use long nosed pliers to tweak them back in.. very carefully.. The plungers are so soft they can be squeezed in too much..If you put some wd40 or crc in there and tap the aluminum, before trying to turn the plunger it helps. There is I think a bit of tube looking aluminium where the plunger goes in, if you tap along there it helps vibrate the oil in and expands the tube.. If you get the plunger out even if it's damaged and needs the kit, it saves the carburetor and the cable. I'd fix the choke and do a standard sort of tune and then see what to do next. Check the valves, sparkplug, airfilter, exhaust condition. The aftermarket carbies are generic tune. They probably sell the same carby as fitting some big street bike. They don't suit every bike or market. They nearly always need some adjustments. I'd recommend fixing the one you have. I like the sound of your place there Ironworker.. Kids and all. Dirt driveways are a never ending job.. and the trees just keep growing too.. Have fun.

And if it is just the plastic nut broken, those are the same on a lot of makes, and some makes sell the nut separately. They are $11 Aussie for a suzuki one.

Good point Gw. I'd forgotten about those plastic ones..

That part has probably damaged the threads in the aluminium where it screws in. There's a nut which you should be able to see, if you undo that all the other pieces inside should pull straight out.. The inner most part does have a habit of seizing in the aluminium though. Probably best to have a go at getting it apart and seeing if the aluminium's ok, and whether the choke plunger is seized in, then deciding on a course of action. If the choke can be repaired then a carby clean is probably the best option. Genuine carbies are a terrible price and aftermarket ones almost always need playing with/tuning to get right for the bike..

These are just cheap bins. My bins get a bashing and one's cracked down one side from being too rough on it.. Cheap tough bins suit me.. They are super handy..

I've got a couple of plastic "fish bins" on my bike. I made mild steel straps running down inside for strength and the outside straps have hooks that hook under the carrier rails to keep them in place. I can push the bins at the top and they tilt forwards or back and dump whatever's in them. They are handy general carriers, and I use them to shale my drive. Shovel the shale in and tip it out. Tossing stuff in them's easier than tying it on.. and I've already got enough tied on with the spade, shovel,, pick, rake, slasher, and sometimes firewood. The bins, when they aren't being used for shale have handsaw, kero, axe, wedges, short ropes, sledge-hammer, chains, chain-block and shackles, spanner.. stuff that's hard to tie on..

Yes you need to take that belt drive system off and fix the wear, and what caused it. There should be some identifying numbers somewhere. There might be a plate on the steering head or frame somewhere, or there might just be numbers stamped into the frame. If you post a picture someone may know it, or, paste a picture into google and see what it finds.

The video didn't work for me. That brass dust/chips will be coming from a bush behind that outer pulley sheave. It sounds like you have several problems to fix now though, and if that bike is as badly made as I think it is, it might be time to cut your losses and quit with it now. I'd try and identify it first off. You need to know whether pars are available, and how much they might cost.

Here's the diagram. I've looked at a few and they all seem the same. If the key is off the fan circuit shouldn't be connected to anything. Even a short to power in the fan power wire, (which could keep the fan running), wouldn't make it not work when the key is on. 2004.bmp

Leaking exhaust at the head, or muffler, or a modified "high flow"(empty) muffler. Does it idle ok ? Does the mixture screw change the mixture from lean to rich in a half to one turn ? Have you been adjusting the idle speed and mixture to get the best idle at the slowest speed possible. with the idle speed backed right down ?

Ha.. good stories Ulf.. I've had bikes stuck and the quad, and subarus, but I haven't driven any trucks/utes off road, well not far enough to get them stuck anyway. . My sons are bee keepers and they are always coming home with pictures of proper 4x4 trucks sideways at what they tell me is seventy km, with four or five tons of hives on, or utes with a front wheel over a bloody big drop, on a bad camber, and uphill.. I've been out with them and it's running out the winch cable to get in, and again to get out of sites. All in a days work. They love it. Head off at 2am to get there an hour before dark.. working away quietly with the bees in the first glimmer of light, still and cool, gentle murmer of voices as they discuss hives.. Bloody lovely way to make a living and work.. Some of us are lucky... Oh yeah... and the point.. I taught them the ways.. And so it goes on.

ha.. It's a good test of them if they can back down.. the weights all go to hell, the brake proportioning all goes to hell, some transmission systems think it's fun and try to go faster, others just disengage... and then they need steering.. Well done. I think I would have got off, roped it to a tree if needed, and swung it around the other direction. I'm a sook !

I saw your appraisal of the quad Ulf.. very good.. Good to get familiar with them. (no not like that ! )..

I've looked at a couple and they both show the key switch having two power in and two power out, both working in parallel. One power out feeds the fan only, and the other power out feeds all the rest. I'd guess the switch needs pulling to bits.. one of the slides playing up.. I'd say. But check it with a gauge before you pull it off and to bits.

Ok.. I had a look at what I hope is the right manual, and I'd be checking the key switch's operation.

I like nature Keys. I don't tear it up.. And that is a jeep, with road tyres.. Waaaay out there with you explorers... The trouble with lies is that they don't stay the same in our minds when we are retelling them.. It all gets confused and we contradict ourselves.. It's a bugger really..

I think we're just getting confused by it's road tyres Dave.. They make it look like a jeep out in the wilderness.. Bahahaha.....

The orange thing in the picture sure looks like a jeep.. No matter.. What would I know..

Do you know the full model designation ? ymf450*** What are the *** ?

Lucky the jeep was able to get to you huh.. No Jeeps if you go out with Ulf..

Manuals are available to download elsewhere.. Some you can read and search one page at a time online which is handy if you have limited or slow data/internet. Handy too to verify it's really for your model before you download.. But keep posting.. and you'll get one here. Your bike is water cooled right ? And does it have belt drive, or a solid trans with five speeds, and if belt, how many forwards speeds does it have ? I'll see if I can find the right manual and have a look.

Your point being ?

Yeah very nice. I do think it looks a little better with the small hook.. but what the hell.. make it a feature. (as my builder mate used to say).