drewpy

pilot system too lean. do a search on forum, talked about plenty of times

not really, the wire from the switch was already there, being part of the left switch loom. I just had to buy some japanese type bullets and solder tup o the ignition switch by copying the old one I had.

I'm using 10w 40. I did use 20w50 and if you have really hot weather then i would go for that. I use semi-synthetic as full synth with make your clutch slip!! the best tyres i have in use are Bridgestone BT45, the RD boys recommend these as well As far as tuning goes Megacycle cams do a reprofiled cam for the xs click here for specs etc try bike bandit as they will list your bike and also publish data. Drewpy

Wecome! Keep your eye on the garage as mods go in there Drewpy

# check your valves as they could be leaking/mal adjusted pilot screws as a keyster kit from sirrius online in canada or I got a set from motoward yamaha dealer (just google)

try here

I use the smallest i could find with a see thru bit so I know I can check for fuel (if the bike starts mis behaving) on the move.

re-check your clutch actuating mechanism has been installed the right way round and is fed correctly with the screw part. Also check the "fingers" of the clutch basket that they are not ridged as this will prevent the plates separating. you can dress them a bit but not too much or the plates will start chattering.

gasket from here POR 15 is the stuff you want for sealing, check the prices and compare with the quote.

the springs should measure 34.6mm free length. if they measure 1mm less than this, then they should be replaced. Is the mushroom head on the end of the rod? check for warped plates using a sheet of glass

yep they control idle to 4 - 41/2 K revs. my bike used to rev on idle which means too lean. just richen up on the pilot screw.(after you have unblocked it)

just get them ultrasonically cleaned, you can buy cheap ones, but big enough for your carb and they also clean your dentures!!!

I suspect the ball bearing at the end of the pushrod is missing

UK bikes don't have relays. the 4th wire feeds the main beam pass switch. I had to solder an extra wire from the ignition switch live to the pass switch on the left side and back to the headlamp main beam.

its your pilot jet, this is the smallest drillings in the carbs and will clog up first. You also need to fit a fuel filter as your tank will have rust particles from gas stations and in the tank itself. Try some of the proprietry carb cleaner you put in the tank and see if it unblocks. You could also open the screw another 1/2 turn and see what happens. mine always runs the roughest at 4k revs. this is the point where the main jet starts to take over from the pilot system. Just age and 30 year old technology really.

If youv'e had the bike from brand new and you can say you have never had a screw driver on the pilot, you can eliminate that then. if you have the carbs off, take out the pilot screw and feel under neath for a little "pin" if its there its snapped off!! Its an air screw, in for rich out for lean.

A common problem was hamfisted peeps overtightening the mixture screw in, then the fine brass tip snaps off in the carb body prventing any change in the low speed mixture. my carb had both of these and got an engineering friend to "push" them through. It opened up the hole slightly but I just screw in the new screw more.

all the points do, is pass 12v to the coils for the appropriate amount of time (dwell). I did say do your timing first, assumming that the points gap was already initially set (which they are) then reset them after the timing

I would try it as you will get better acceleration. I had a similar setup and i was great. fuel consumption was worse and you tended to race other bikes/cars up to 80mph, so engine life would be shorter. I now run 1 tooth over just to tame my red mist

do the timing first, then reset your points. invest in a Xenon strobe £20 off ebay.

I'd also get a parts book, as this illustrates all the parts and you can phone suppliers with parts numbers. I have haynes, Clymer and Yamaha manuals which differ in their presentation. I would say Yamaha manual to have the most information with torque settings and diagnostics etc

Carb issue, pilot jet

the balance pipe in the xs400 was to effectivley lengthen the pipe so they (yamaha) could fit a shorter silencer to get the look right and still comply with the regs.

Just google "engine wise" and the top search is the kit!! I thought that if you could seal the area around the pet cock after t has been removed and pour in the solution into the tank, you could achieve the same result. I have used this method on brackets etc in a bath and it will remove the paint. It also get hot depending on how much you insert the cathode (stainless rod) you do this at your own risk BTW don't come back to me with tales of woe

I didn't know till this post!! I had gone at 4:40 to beat the crowds so fortunatly didn't witness it.