Airhead

Hi wnd welcome to the forum. the first things to do will be check for spark and if sparking check for fuel delivery (wet plug) we'll take it from there. ...Paul

sounds like a classic case of pilot jet blocked, remove the jet can you see daylight through it. Further cleaning of carb would benefit you, ultrasonic if possible and blow through the circuits with compressed air. If you are going to use carb cleaner remove anything that has an O ring on it first.

Try the LC forum Here

Be an optimist, might just need a new battery, measure the voltage across the terminals.My car did this whan a cell went down, speedo all over the show and just a clicking when the key turned, new battery fixed it...

Try Here ...Paul

Hi Karl. maybe the 3 in 1 oil wasnt such a good idea, could it have gotten ito the electric contacts of the switch? (Oil is an insulator). I would have used a spray of WD40 myself as this seems ok in switches. you may have to remove the switch and soak it in something like white spirit, then dry it and leave it in a warm place to evaporate any spirit residue. Follow this by a light spray of WD40 You could always try bypassing all this cleaning by spraying with WD40 operating the key...repeated times...crossed figers and all. ...Paul

Welcome to the forum John, here is the info you need, it goes without saying the fuel feed is the large spigot on the other side. ...Paul

LOL brilliant.

Cool...was that the neighbours hand putting a stop to it all?

That looks a great buy for the money you paid, its obviously been well cared for and dry stored, can see why you bought it. Welcome to the forum weve got lots of XS400 expertise here...(not me though)...

Honestly mate what your'e saying does not compute...it runs fine with no filter and filter lid removed, yet it chugs with no filter and lid re-fitted...thats incredible...either that or something is blocking the airway into the filter box, have you checked this? perhaps theres a dead mouse in the snorkel...

haha...thats the future!

why not troubleshoot what you have, the cdi version (if there is one) will be expensive to convert to. Has your bike got an ignition switch and a kill switch, if so unplug them both, (start with the kill switch) and check again for the no spark situation.

Dunno, never heard of this but for what its worth, check the reservoir cap is vented ok if there is a return spring on the brake lever, check it is attached and functioning Lubricate the brake lever pivot point

so what was the first magneto, have you still got that one along with its backplate and coils etc? if there was no points in that one it is a CDI version isnt it?

Hi not sure about your bike but this may help anyhow. with my DT175MX (DT175E) in the manual they say use this tool and attach as shown one side in an unused threaded hole and the other side in a threaded hole used for the bearing and seal tetainer ...see pic I made my own Goes without saying though that great care must be taken to ensure that nothing mechanical is still holding the cases together or you could quite easily damage the cases. ...Paul

Your generating 3 phases so a 6 diode rectifier converts to DC and the zener controls the voltage, just do the usual checks on the rectifier, pass one way not the other etc and if thats ok get yourself another zener, maybe from RS or somewhere ...i dunno. with the right equipment you could even check the function of the zener i suppose, just need a bench DC power supply and at the most a multi meter

rectifiers and zeners dont serve the same pupose though.

Ahh so you did for the last day at school instead of the prom night, cant blame you for your impatience though...have fun...looks fantastic...

Nice one Brian, welcome to the YOC...

Stop shouting...Caps PM me your email and I'll send you one ...Paul

You could try emailing Electrex World Here they list the DT175 but I didnt see the 250, worth contacting them though. I bought an ignition source coil fro there for my DT175 and although it wasnt right in the resistance value band quoted by yamaha it seems to work ok and was a lot better than the rusty old thing it replaced. Heres the old one and the new one fitted Even if they dont list one for your bike, they may be helpful and if you email them a picture and quote the mounting hole centres they may find it is the same as some other models that the list for.

Surely if your de compression valve is faulty...compression would be your problem!

You have already been given a link to the aircooled rd club earlier, obviously this would be of benefit to you. you could also try the VJMCc if you want to. VJMCC = Vintage Japaneses Motorcycle Club

Check continuity of the ground connections to the battery negative (the outer shell of the bulb holders?)