XT 600 Revival

[McGoo]

I bought this bike at auction a few weeks ago in the hopes that I could get it home, add fuel, start it, and ride off into the sunset. Unfortunately, that was not to be. I knew that buying any bike without being able to see it run was a risk, so I wasnt overly butthurt at finding the bike had issues (at least not yet anyway). At the moment Im treating the whole thing as a learning experience about engines and bikes in general, as it is the first one I have ever owned.

For those looking for Hewie/Dubs type bike porn and expensive bling, look away now, as this whole thing is being done on a tight budget, and even when it's done it still isnt going to be amazing, but it will be a functional, useful commuter/trail bike.

I dont have many photos of the bike in its original state as I started pulling bits off as soon as I got it home. It's ex-army, and you can see the blackout lights on the front (one amber light to be seen, one dim light pointing down to see where you are riding, another amber one on the back), the leather panniers, the Acerbis 22 litre tank, and the general condition of the bike here.



As soon as I got it home I jumpstarted it and got it running, and was quite happy to find a distinct lack of clattering, smoke, and other unwanted bad ju-ju from the engine. the engine didnt want to rev a lot, but I figured it was a tad cold and didnt worry about that too much. I purchased a new battery and spark plug from Southern River Motorcycles and had an interesting chat to the owner (I think) about my bike and the other ones at auction. I paid $1400 at the hammer, $1655 with fees. He said last auction they were going for $3000+, so Im feeling quite happy with mine.

New battery in, still wouldnt start, so I started to tear the carbs down. I downloaded the workshop manual from Useful Stuff | Moto Andalucia and was using a step by step guide from XT600 1/23. I dont have any pictures of the first time I did this as I was a little excited by it all, but I found a mainly clean carb, which I was happy about. I did get a bit intimidated by the carb, however, even with the guides to help me, so I didnt really get very far. I stopped once I had the float bowl off, and the primary needle out. This was good and bad, as I found that the main needle was bent. I dont know if it was from me or not, either way it's shagged. I spoke to a few people, some said replace, some said try the old one and see, so I put it all back together, only to find the bike still wouldnt start. Fuggit.

I spoke to a few more people, and tried various things like putting oil down the spark plug hole in case the rings had dried up and I had lost compression, I put in a few new spark plugs at various stages, I drained all the fuel (tank and carb) and replaced it followed by another spark plug, still no starting. I put a few drops of petrol down the spark plug to see if that would work, still nothing. All of this cranking must have taken it's toll, as the starter slowed briefly, as if it was loading up, and then the starter began spinning all by itself without turning the engine over.

This was a bad thing.

I asked around a bit more, and was told that the most likely thing was I had sheared the bolts that connect the starter clutch to the flywheel. I see this as both good and bad. Good because it's not an amazingly hard fix, bad because I dont know if the bolts sheared because they were simply old, or there is something more sinister going on. Anyway, the mechanic down at Five Star Yamah said that if I did the prep work, they could pull the flywheel off for me in a few minutes, so this became the new priority. I ordered a carb kit from England, and a whole engine gasket kit from Canada in preparation for putting it all back together.

So I started the second tear down today, and thought I should photograph things this time round. Amazing how much easier and quicker things are second time round! Here it is with tank, seat, side covers and carby removed.



Close up view. Note the high-tech glad wrap covering the inlet manifolds.



I was looking for a way to organise screws and the like, as some of them differ in size in different locations. So I came up with this:



I drew a rough picture of the cover, and as I pull a screw off I stab a hole with a screwdriver and put it in. Should make putting it back together easier!

The starter cover removed, showing the drive gear, the idler gear (attached to the cover), and the second idler gear theat spins the starter clutch




The second idler gear should only spin one way, but when I spin it with my finger it spins easily one way, and a little bit harder the other. This confirms that either the bolts are sheared, or the clutch is shagged, either way the cover and flywheel are coming off. While Im at it Im going to get a multimeter and check the stator out, as this may be a part of why the bike isnt starting.

So now Im off to whichever hardware store can sell me a set of decent allen keys, and a cheap multimeter, so I can continue the teardown. Hopefully I'll be able to get the bike to Yamaha this afternoon and get a diagnosis.

The immediate plans are:
*Fix the starter problem
*Rebuild the carbs completely
*If it still doesnt start, start looking in to other mechanical gremblin areas.
*Make sure all lights are working and get it over the pits and registered.

Future plans:
*Get a lighter and louder pipe. I have seen quite a few people put on supertrapp mufflers for lots of dollars, or some others use one from a 2001/2001 GSXR 750/1000 with a few mods. This will be dollar dependent.
*Remove the army gear from it. I have no need for blackout lights or a gun rack. I will, however, keep the rear rack for now as it is bloody strong, and should be useful for commuting.
*Respray the plastics, not sure in what colour. Im a bit limited by the tank as it is breathable plastic, meaning most all paint will crack and bubble not long after being applied due to the fumes leaking through. The only realistic option I have seen so far is perforated vinyl, or you can sand and heat the plastic to restore the natural colour.
*Perhaps get a metal pannier kit for touring. I would love a Touratech set, but at $500+ per pannier, plus the mounting kit, I think I'll be saving for a long time.

[McGoo]

Good news today. I took the bike down to Five Star Yamaha this morning and wheeled it into the workshop. Two minutes later they boys wheeled it out with the flywheel now loose, and no charge required. Quite chuffed, I was. While I was there I grabbed some new oil and a filter, been meaning to do that for a while.

Got it home and pulled the flywheel off and separated the starter clutch out. I had suspected the bolts holding the flywheel to the starter clutch had sheared, but they appeared intact. I was trying to work out what the little lump on the crankshaft was when I realised it was the remnants of the woodruff (sp?) key that had sheared off. Excellent! Not only did it mean I hadnt pulled all these parts apart for nothing, but even better was the low cost of the repair. $14.50 and two days from Yamaha, and they will have a new one in stock for me.

Now just need to wait for the gaskets and carby kit to arrive and I can put it all back together and see what happens. Should be running in two to three weeks. In the meantime I m going to borrow a multimeter and go over the electrics, make sure they are all ready for the pit inspection.

[Neil-51]

You will probably save time and money if you take the advice you get and try and diagnose problems yourself, before pulling stuff apart.

It is great that you are doing this and learning along the way. Working on your diagnosis skills along the way will be a bonus. Basic diagnosis start with three things require for the engine to run - compression, a spark and fuel. You can do a rough test of compression by pulling the plug, sticking you finger in the plug hole and cranking. While the plug is out check for a spark. If it has a spark, but doesn't start, pull the plug again and check it it is dry..could indicate no fuel. Try and target the problem area and work on it with further diagnosis.

The fact that the bike started and was quiet when you first got it suggests you aren't far away from a winner.

[emrys74]

also you could spray a bit of aero start down its throat if it tries to run its fuel

as for the multi meter just get a cheapy and a test light from auto one or MALZ there not expensive $10 for a test light so handy for checking power and earths and a multi meter is only $20 $25.
They be handy to have in the shed any way.

[McGoo]

You will probably save time and money if you take the advice you get and try and diagnose problems yourself, before pulling stuff apart.

It is great that you are doing this and learning along the way. Working on your diagnosis skills along the way will be a bonus. Basic diagnosis start with three things require for the engine to run - compression, a spark and fuel. You can do a rough test of compression by pulling the plug, sticking you finger in the plug hole and cranking. While the plug is out check for a spark. If it has a spark, but doesn't start, pull the plug again and check it it is dry..could indicate no fuel. Try and target the problem area and work on it with further diagnosis.

The fact that the bike started and was quiet when you first got it suggests you aren't far away from a winner.

Yep, Im loving how much Im learning about engines at the moment. I thought I knew a decent amount before, but knowing how an angine works is very different to looking at a gear and looking for signs of wear, dry bearings, etc. So far I have spent around $350 on gaskets, carb kit, oil, filter, battery and spark plugs. If I was paying someone else to do all this, I wouldnt be surprised if that figure doubled or more.

At the moment Im wondering if the key was slightly sheared when it wouldnt start. Holding together enough to make the engine spin, but far enough out to screw up the timing and make it backfire. If so, I've just saved myself from ripping into the head, which is a major plus.

also you could spray a bit of aero start down its throat if it tries to run its fuel

as for the multi meter just get a cheapy and a test light from auto one or MALZ there not expensive $10 for a test light so handy for checking power and earths and a multi meter is only $20 $25.
They be handy to have in the shed any way.

I picked up some Start Ya Bastard (love that name) from repco yesterday, and I am going to borrow my dad's multimeter and torque wrench from the farm. I will have to convert all the torque settings from Nm to lb/ft as it was originally my Granddad's torque wrench. I figure that as long as I double check my conversions, it should work just fine. And you just reminded me that I have a light-probe diagnostic thingie, one of those ones that lights up when it hits power. Cheers! That will be good for the lights, but I want to check the resistance and voltage drop to the stator, coils, etc.

[Neil-51]

At the moment Im wondering if the key was slightly sheared when it wouldnt start. Holding together enough to make the engine spin, but far enough out to screw up the timing and make it backfire. If so, I've just saved myself from ripping into the head, which is a major plus.

I was thinking the same thing. So, work out if the ignition pick up is at the end. If it is, you may well have the answer. Before you muck around with stator and coil readings, check if you have a spark.

[McGoo]

I was thinking the same thing. So, work out if the ignition pick up is at the end. If it is, you may well have the answer. Before you muck around with stator and coil readings, check if you have a spark.

I had a spark before the engine stopped spinning, but Im not knowledgeable enough to be able to rate it's quality. From reading other threads on the bike, I can put the multimeter across the stator while the cover is off and test resistance now, so while it's all apart it's no problem to check. It's a lot easier to check it now than have to pull the cover off again later!

Im now in the market for some riding gear. I have helmet, light textile jacket, draggins, and summer gloves, but if Im going to be riding more I would like some better quality gear, and maybe some dual purpose street/trail gear. First on the list is proper riding boots, then the rest in whatever order I can get it in. Is anyone using a Leatt brace? I'll have a look for gear reccomendations on the site soon.

Any tips for boots that are suited for both street and trail use? Waterproof would be a bonus.

[McGoo]

Crap. While trying to remove the float pin I managed to snap the tip off the casting that holds it in.




Apart from beating myself severely, Im trying to work out what to do next. So far my options appear to be:
* Leave it as is, reassemble it, and hope that it all holds together (advice from a motorbike shop, but it was a salesman, not a mechanic). As the float is, well, floating in fuel all the time, it has very little to no load on the area, and should be fairly vibration free. But then, there are two legs for a reason.
* Remove the pin, use JB Weld or similar and glue the tip back on, and maybe use a drill or something to make sure the glue doesnt interfere with the pin. And hope that I dont screw up the other leg as well.
* Leave the pin in, and carefully glue/weld the tip back on, and hope like hell that the pin doesnt get glued into one position

Any ideas/advice? Any people in Perth who specialise in this sort of thing?

If it isnt salvageable, I'll have to look into whether or not an earlier carb will work (with the correct jetting/needles), as they are available on ebay for around $100 delivered. A new one from boats.net is $750, half what I paid for the bike!

[Neil-51]

You could leave it and hope for the best. You would need a specialist glue to survive in fuel.

Unless you are replacing the needle and seat, or it is overflowing, why pull it apart?

An option would be to drill a fine hole in the remaining stub and use stainless lockwire (as used on race bikes) to retain the pin.

[McGoo]

Unless you are replacing the needle and seat, or it is overflowing, why pull it apart?
.

I started pulling it apart because I thought the bike had a carb problem, and ordered a whole rebuild kit for it. The carb has seemed pretty clean so far though, I was just dismantling it because I had the new parts and thought "why not". Im happy to leave it alone if it means that it works though. the fuel bowl gasket was leaking, but I dont know of any other specific problems with it. But then, I havent got the bike running, so for all I know the jets are clogged.

[darkfibre]

You could machine/file the post down a little, then tap a small thread in the remainder of the post. Modify a small bolt by drilling through the head to take the pin.

[Shady7/8]

Try running the carb through an Ultrasonic cleaner - should help to clean out any bits clogging teeny pathways.


I have one if needed - will fit the whole carb, but better to break down a bit.

[Shady7/8]

You could machine/file the post down a little, then tap a small thread in the remainder of the post. Modify a small bolt by drilling through the head to take the pin.

Too risky in my opinion - if you drill it keep it simple and lockwire

Plus the bolt might not quite fit if you leave the head on, and dremelling off adds it's own risks.

[McGoo]

You could machine/file the post down a little, then tap a small thread in the remainder of the post. Modify a small bolt by drilling through the head to take the pin.

I had vaguely thought about something like this, but that would be a fecking precise hole, know anyone who could do it well?

edit: I would think the same thing for lockwiring it, as there is only a few mm of metal to drill into, so same question for this too.

[Shady7/8]

drill press and a 1mm drill bit.

[rgvlee]

What about something like devcon/kneed it/jbweld?

[McGoo]

What about something like devcon/kneed it/jbweld?

I've heard of all of them but I dont know which one is best given it is cast zinc alloy, if they will be string enough (not that I think strength is a major factor), and it will be submerged in fuel.

[rgvlee]

I don't necessarily think one is better than the other, they are all an epoxy. Can be used in some extreme situations, i.e., flowing crank cases in 2T.

[richarde]

Maybe a good Tig welder would be able to build it back up with weld? I don't know how weldable it would be though. You would still need to redrill the hole and get it accurate enough too

[g0zer]

knead it works well for large applications, to get it to cure properly for small jobs you need to heat it stick in an oven on low 50C for a couple of hours. ie: a small amount will loses the heat of the chemical reaction to atmosphere and wont cure properly.