JimR

There is a possibly a chance of that rebuild the engine and check the tolerance

The shims were in place to take up manufacturing tolerance and therefore can alter per engine. best thing to go is :- dry run building the engine and see how much end float you get. However from memory those shims were about 0.01mm thickness each and most engines had 2 or 3 each side, so perhaps a single shim of 0,03mm either side will do .. but this will depend on end float

I have one on my fizzy

http://www.powerdynamo.biz/eng/systems/7340/7340main.htm

Back in 72 (T)(turn) was (F)(flasher)

Well apart from filing away the exhaust port, changing the carb, inlet manifold, reed valve and exhaust system you will have to change the primary gear & clutch as the ratios were changed to ensure the max design speed could not be exceeded ... TBF I agree with Cynic

To Set the valve Timing :- set cylinder 1 (nearest to the left) to tdc then ensure both marks on the cams match the marks on the cam caps ..refit the cam chain tensioner .. spin the motor clock wise at least twice & recheck at this point (dependant on the state of the cam chain & wellar tensioners) .. if incorrect drop the cam(s) off 1 tooth against the direction that the timing moved to .. if you have new tensioners & chain this should not happen .. good luck !

However with the correct vacuum Fuel shut off valves, as you can see from the image the petcock is totally different to the one in your image without these there is a chance you may have to do some mods to get around your problems

Those petcocks are not as Yamaha intended ... which may indicate some issues .. looking at them they look like Kawasaki petcocks which are not vac controled .. I guess the 2 vac take offs on the inlet manifolds have been blanked off so no undue air is being allowed into the inlet tracts ? I would doubt that Yamaha would have given the UK vac petcocks and the US manual ones from my time at the factory they would use as many common parts across as possible through models for different markets ... I would guess your after market petcocks are just not allowing the volume of fuel through to allow the engine to run

Hi first off the xs1100 petcocks do not have an off position they have on-res-pri .. the pri position allows fuel to flood tho where as on & res only supply fuel when a vac is formed via the engine being started .. you should only use the PRI position on the petcocks to 'prime' the carbs with fuel after work on either the carbs and/or motor. However with the age of XS1100 you may have knackered the diaphrams within the petcocks. The Dull sound from the exhaust sounds like the fuel lines have been routed wrong .. have you removed the carbs and/or the fuel tank recently ?

I fixed/commissioned these bikes from onset (1976 onwards) however most of the tools that were around at that time have long since gone .. so I guess there are more users that have worked out fixes

Can you rephrase as I would have thought rev = high RPM's ? the leak in the carb would indicate an issue with the float or needle jet .. that said as the carbs are old they may have just gone past their sell by date

before top dead centre (center) The coil should have an orange or black wire attached The points are located in the magneto ... l/h engine side cover but you will need an extractor to remove the mag in the UK UK you will need a P134 extractor see https://picclick.co.uk/Flywheel-puller-extractor-Yamaha-FS1-FS1E-310667328436.html

Hi First off set the ignition timing to 1.8mm btdc and dress the points ... there after just check the ht coil for the correct resistances ( they elude me for the minute) and the resistance of the plug cap

hmm I guess you ment the V70 ? most chassis parts will interchange ... the U range were the fore runners of the V range and share very little with the V range .. so if you want stuff to fit your V50p get stuff from V50,70.75,75A,80 and 90 and not the U series and going back really forget anything for the MF series

just a thought .. how come the exhaust valve clearance was double what it should be ? my guess a broken valve guide/bent valve .. which in turn would give the bike low compression which would follow through which the way you can only get the bike to run e.g Revs .. I would compression test the engine, both wet & dry and work out from the (possible differences) what is broke. @Airhead The white smoke may be oil burning that is running through the possible break in the valve guide .. at this point the valve guide oil seal is ineffective and allows oil to run into the combustion chamber and therefore burns as wispy white smoke rather than water vapour

it used to be called a rattle pad .. it stopped the the brake squealing and juddering ... glad you got it sorted

That looks like it comes from over a brake pad .. did you remove the pads ?

you need a DTI, using this wind back from TDC (BTDC) by 1.8mm and the points should just break at this position .. there are no flywheel marks

what bike ?

balance the carbs & reset the mixture strength if it is an early YICS version remember to block the swill chambers .. but from memory there were only a few 600's with a YICS head

aha its a 12 volt one with leccy start !!! check the battery is charging when you get it going again .... (you will need over 12V in order for the bike to start) you should get 14.5~14.8 volts at around 3k rpm .. the die after 5 mins could be due to the battery voltage droping to low .... are the brushes long enuff ... if you can not see the red ware mark replace them as a matter of course, if this is good you need to look at the VR unit .... if you undo the 2 screws on the VR lid you may see a rather burned set of points, which you dress down and perhaps alter the red painted screw (this alters when the charging kicks in) screw this in Correct ign timing method :- set the engine to tdc and gap the points to 12 thou ... open the bob weights on the advance unit .. I used to use a cycle spoke bent in half to ensure we were at full advance then wind back 1.8mm and get the points to break also check when you refitted the advance unit that it lined up correctly with the groove in the rotor

It's odd it backfires if it is fuel starvation .. with no fuel one would expect no back fires (nothing to combust) can I ask how you set the timing ?

you need to play with the VR ... the box with loads of wires going to it ... just forwarad of the oil tank ... remove the top ... and clean the points ! which is good .. unless you have altered the screw that has paint on it ... have you ?

So this is electric start ? if so use a slide hammer to pull it off