xmastree

Ooh, just down the road... Problem is, do I take the bike, or the car so I can buy loads of shite?

It's here Last night I was out with a mate for a few beers and we were discussing this problem. One thing occurred to me. The starting circuit and the ignition circuit are completely separate. Therefore the intermittent fault is probably a short between the two. There's one wire from the starter button to the starter relay. There are six wires at the ignition box, excluding the supply (which I've confirmed are ok), they are two from each pickup and one to each coil. If the pickup wires are fed with a high impedance 12V from the box, and that wire was shorted to the starter relay wire, they would have the 12V when starting but once the button was released the relay coil would be connected to it. That may affect it and kill the signal to the ignition box. It's the only thing I can think of which makes sense. I'll try running a new wire for the starter and see how it goes. Good idea. I can't believe I hadn't thought of that.

Well, the trip went without too many problems. When I first started it, it was fine. So I put the side panels back on and it died the instant I clipped on the LH one. Hmm.. interesting. Off with the panel again, fired it up again and thumped the ignition box. It died. Started again and carefully replaced the panel. I then took a deep breath and set off on the journey. It was fine, never missed a beat the whole way. It seems to be happy once it's warmed up. On the way back next day it died just once, minutes after setting off. I restarted it and it was fine after that. Another problem manifested itself later in the journey, fuel starvation. I have a filter in the line so I can see what's going on. That came in really handy, especially as I can see it while riding the bike.When it first started misfiring I thought it was simply running out so I switched to reserve, but it didn't clear the misfire. I looked at the filter, which was empty and fuel was dribbling into it. Found a petrol station and filled up, but it was nowhere near empty. Turns out there is something blocking fuel flow and if I cruise at over 60 mph the flow is insufficient. I kept an eye on the filter and if it became too low I just slowed down. I'm pretty sure I can fix that by having a look at the petrol tap. The filter is probably gunged up. Was it a nice day yesterday, or what?

And another... ">" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"> Love the vocal work!

Indeed. The previous owner has been in the headlight. there are little masking tape 'flags' on all the wires... The interesting thing is on the indicator wires (even the front ones which go directly to the indicators, so there should be absolutely no doubt what they are) the flags say 'TRAF' which I presume means trafficator. Only someone of a certain age would use that word... I'm surprised there wasn't a label on the battery saying 'Accumulator'!

Everything checks out there. If it were that simple then the bike wouldn't run at all. Not that I am aware of. Well, nothing on the diagram at least. The bike wiring may well have been messed with at some point in its life. But I suspect a wiring fault as such wouldn't allow it to run ever. This is intermittent...

That was my first thought, but having checked he manual, there isn't anything like that. +12V goes straight to the coils and it's healthy. The trouble with the coils is that they're up inside the frame under the tank. Rather inaccessible, there's this engine thing in the way. I can get to the connectors though, and everything seems ok there. Cheers, I have the official Yamaha one.

I think I would have kept it on once I'd discovered it...

I really want someone's clutch cable to snap...

Are they the correct wattage bulbs? They're not LED ones are they?

Paddy and Mick are being interviesed for a job on a building site. Paddy goes in first, and the foreman asks "If I poke out one of your eyes, what would you be?" "Half blind" says Paddy "and if I poke out the other?" "Totally blind." "Very good, start on Monday. Now go out and send your mate in" So Paddy goes out and says: "It's easy, the first answer is 'half blind' and the next is 'totally blind' " Mick goes in, Foreman says: "If I cut off one of your ears, what would you be?" "Half blind" says Mick "and if I cut off the other?" "Totally blind." "How do you work that out?" "Well sir, my cap would fall over my eyes!"

So maybe the vacuum as only operating the tap when the starter was running... The trouble with that theory is that when I release the button it would stop dead, even at high revs. Just like the ignition was turned off. Presumably if the fuel was shut off it would splutter first. Although it's not as wacky as one of my theories. The ignition box can sense that the starter is turning and delivers a bigger spark for the duration. But there's no connection between the two so it would have to sense the supply voltage being lower than normal. So far so good, but revving it with the starter running should spin up the generator and restore the healthy supply.

Sucking fuel down the vacuum pipe straight into the inlet? Interesting concept, but I suspect it would only run on one cylinder if that were the case. Plus I can see fuel in the filter, and it fills up nicely. There's a little voice still telling me it's electrical... Like the ignition box can somehow sense that the starter's operating.

Fuel in the oil can be caused by a dodgy needle valve (in the carb float chamber) and the fuel tap left on prime. This allows fuel to flow through the carb(s) and into the cylinder where it finds its way past the piston rings and into the oil.

Here's a funny one. My XS400 has been misbehaving lately. It will start but dies the second I release the starter button. If I hold the button in, it will rev happily (but I don't like doing that too much). The scary thing is, it only started doing this after I replaced a few things, specifically the LH switch cluster and some wider bars. Now, none of the switches on there have anything in connection with the ignition, but I may have disturbed something in the headlight. So, I've checked the supply to the ignition box, which is fine, and its earth connection too. I've even tried wiring directly from the fuse to the ignition, just to bypass the killswitch and ignition switch. The starter circuit is completely separate from the ignition, which is why it's perplexing. Now it gets weird though. I have a fuel filter, which was showing a rather low level of fuel. I turned it onto reserve and it was fine... So, could that be all it was? If so, how could it rev when the starter button was pressed? It just doesn't make sense to me... Maybe the problem is still there just waiting to bite me at the worst moment. I took it out today for abut one hour and it never missed a beat. Next weekend I'm planning a 300 mile round trip and I'd like to set off with confidence.

Yep, it's a DOHC, also known as maxim, seca, or 12E. As for the fuseholder, I used a MG midget one on mine. Before: After: Check your PM for details of a manual...

It really depends where you are... I know a really good upholsterer locally, but if you're not in West Yorkshire it might not me of much use.

Does it have to be a Radian fusebox? My XS400 fusebox looked like this: So I fitted one I got off eBay for about a fiver: It was originally meant for an MG midget, but it works just fine. Or there's: http://www.vehicle-wiring-products.eu/VWP-...es/holders1.php http://www.vehicle-wiring-products.eu/VWP-...es/holders3.php

My XS400DOHC passed its MOT today but there was one problem which the examiner noted. The rear (drum) brake is uneven. Presumably the drum is no longer perfectly circular. So, what do I do about it? My guess is that I have two options. Either fix it or replace the wheel. If I replace it, given that the chances of finding one are pretty slim, would a wheel from a SOHC model fit? Were any of those drums? My old 250 had a disc... I believe the US customs were drum rears, but a smaller wheel. Could I fit one of those?

I know the problem. I usually end up removing the inlet stubs with the carbs, but there's a danger of danaging the o-ring seals there, so be careful. Another option which I haven't tried yet is to remove the upper engine brackets. This allows the engine to move slightly forwards.

Same reason someone would want the Welsh flag I guess...

Indeed it is, thanks for that. I'd never have guessed...

So, how do I get the English flag? I've searched the list but it's not there...

Well my conscience is now clear, as I have just splashed out on the real McCoy on eBay. Not cheap though, at £25 + £3.50 p+p. I'd post the link, but there was only one available.

Did you forget to include the date, or did I miss it?