drewpy

not just a pretty face yer know!!! seriously, let us all know how you get on for the benefit of present and future posters!

youv'e got more luck, my xs400D spring is exactly the same as yours If you go to progressive rate springs, the springs are a bit longer and a little harder to fit as you have to compress the spring more

one on UK ebay right now

got nothing from the mags, although there was some mention of lesters in the aircooled RD site but nothing helpful. I know they were standard equipment for triumphs in the seventies so it could be your asking in the wrong forum. try asking in Classic bike forum as there that has a good cross section of bike owners (jap, european and Uk bikes)

there is a similarily afflicted xs500 owner on another thread, when I get home i'll measure my springs for the 400 and see what difference there is.

I wouldn't go over £4 I'd have them if they delivered

beats me and all, I think I did try to test once, but gave up and used the 14.5 DCV at 2500rpm after checking the stator, field coil and rectifier. really there's nothing else except a broken wire in the loom, but my loom was NOS

cheapskate try motogrid or bikebandit as they have online parts lists

no idea what the manual is, just got it on a cd from ebay, eons ago on my yam service manual for xs400 ( all voltage regs are the same) 1) ohmmeter (0 - 200 ohms) one probe to black wire and one to reg base 10.5+/-2ohms @ 20'C 2) one probe to brown wire and other to green wire 140+/- 10ohm @20'C 3) 14.5 - 15 volts DC at 2500 rpm hope that helps

if you measure the length and the width of the spring, I'll check mine and we'lll see if they are the same!! Yamaha used parts bins across their model ranges

if you search the forums and put in "xs400 monoshock" there are answers there

lester was a british aftermarket wheel supplier in the 70's, so the wheel could be for anything. being 19" I assume xs650 xs750? I'll look at some old mags to see if i can find any info

I've had loads of probs with the tips of the adjuster snapping off by heavy handed butchers. so i have had to drift out the needle tips thus opening up the jet. not had a problem with slow running as the new needles can close up and compensate for the amount of widening hope that helps edit: i hope we are talking about the pilot system situated top front of the carb via the pilot screw!!

could be 33, 34 or 35mm which is measured out side diameter. it has nothing to do with the springs, you need to take one out to measure it just done a google search and this came up http://xs500.org/XS500e.htm

ignition works by providing 12v to primary and an earth, contacts/cdi then interupts the earth but the current now has nowhere to go except to secondary and then jump the gap of the spark plug as this is the easiest path. maybe you can interupt the earth to create a spark at the plug. ( not too long as the coil heats up) i would suspect either a faulty earth on the cdi or the cdi itself.

I get a screeching noise when I start my bike up!....its usually next door neigbours complaining its 7am sunday morning seriously, sounds like the starter gear is starting to wear, you can buy kits from granby's. there are no tappets in an SR it uses an OHC configeration, is the rattle a tapping noise which rises with the revs? or is it a general clatter (thinking clutch basket!) losing power could be any thing but I'm inclined to think its a fuel supply problem either tak full of crud and/or carb getting partially blocked every now and then

you need to cap the inlet stubs as it will draw too much air. these use mikuni Constant Velocity carbs, which use diaphrams to raise or lower the main needle via the engine induction which gives a smoother response. the throttle cable merely opens a butterfly valve in the carb. you use the stubs on the rubber inlets to balance the carbs

I think its called a "cobalt drill bit" which is well 'ard and did my 3 disks and is still going.

I used a bench pillar drill (£30 from Aldi) and an expensive drill bit for stainless. takes bloody ages though!

the key to good starting singles is technique and spot on ignition and valve timing

thats earth again, as the indicator hasn't got a proper earth it uses the +'ve on the lamp to get to earth and makes a circuit (you see it on cars where the indicators come on when the brakes are used).

Iv'e drilled mine and added an extra disk a la XS1100. disk patterns here https://macshot.de/rd/brakediscs.html

you can get them re-hard chromed by philpots or fitforx to original spec. they cost about £100 for both! have you tried motoward, msnl or motolink?

won't fit

try some straight "Vincent" bars that may offer a compromise?