JimR

hmm had loads of XS250's do this with various causes from the training I received in the early 80's I'll give you the diagnosis path Compression check wet/dry out of spec Remove Cylinder head check valves for leakage check bores pistons & rings for wear in spec adjust valve clearances to the correct values set the dwell angle to 22.5 % set the ignition timing (with strobe) to LF (left cylinder) RF (right cylinder) Always start with the L/H cylinder when sat on the bike Ignition timing & dwell are set at the same time you may set the dwell correct then adjust the timing which will then set the dwell to an incorrect value.... reset the dwell then recheck the timing keep doing this until you have the dwell and timing right check the advance for both cylinders (between the | | marks) adjust the mixture screws for a steady idle (some engines require the mixture screws to be set well away from the default 1.5 turns out) check/adjust carb balance Still running badly check inlet manifolds for leakage the rubber o ring within the paper gasket can fail (you will see the 'gas track' across the paper section of the gasket) if OK check the diaphrams for splits. with a diaphram split this can give you a false reading when balancing the carbs so if you have a split you will have to do a re balance if this doesn't fix it post up again

Hi Mike getting the cover off is no problem as the manual suggests but make sure you have the modified seal (coloured orange, if it is coloured black it will fail in short order). but when you have the cover off and the push rod removed you can prise out the oil seal with a long screw driver (to get the leverage). Care must be taken putting the new seal in, best practice would be to oil/lube the new seal around the outer and gently drift the seal in (as the seal has a metal back a drift the same size as the seal would make sure you don't bend the metal section of the seal), as you do this you may loose some of the outer ring (the crankcase tends to shave it off) but if you drift in square you'll get no leaks

Just wondering how a thread regarding a chain driven twin cylinder bike will have any bearing on shaft driven triple their engines do differ a hell of a lot

Hi Paul, once set for your riding style maintaining the RS200 was no more difficult than any other 2 stroke twin (designed) from the 70's the Suzuki SB200 for example had CDI where as the RS had points which did make it a little easier to maintain. Normally the only complicated service work is setting the timing and they were fine. If the electric start has been used a lot you may find the genny brushes to be well worn, you can check this by running the motor & seeing if the charge light goes out over 1500 rpm Regards Jim

Hi Paul Yes I have owned an RS 200, back in the day it did not sell well so 1981 registration may not mean 1981 model ! In the UK we had 2 versions, one with a single seat & top box ( and a seat pad that replaced the top box if you carried passengers), the other version had 'hi rise' handle bars & a duel seat. To be fair the bike was good (both versions) but suffered from a few problems (in the UK). The bike was really never meant to come to the UK so when it was here needed to modified to run correctly. The problems were :- Plugs oil fouling if ridden slowly - Fix, reduce the minimum stroke for the oil pump and change the plugs to a softer grade ( I just cannot think of the grade but if the spec is B7HS then install a B6HS) and adjust the ignition timing to 1.6mm btdc fully advanced Heat Seize if ridden fast - enlarge the size of the main jet, keep the plugs per spec set the minimum pump stroke to spec, adjust the ignition timing to 1.8mm btdc fully advanced. It then became a little more difficult if you use the bike, mostly slowly, then thrash the nuts out of it (holed pistons) or if you thrash it most of the time and do some slow work with it (oiled plugs). Most of the time it was good to adjust the minimum pump stroke, this allowed good centre ground. When the RS200 was 'on song' it was an awesome 2 stroke twin with a single carb ! Regards Jim

Hi Carl, I suggest you look at the starter clutch

umm ok .. just a thought why do you not get jewish morris dancers ?

Like Wow you have a problem that made me some money in the 70's !!! ... The main fuse getting hot .. this indicates a short within the 12v DC system, this may be the ignition switch, reg/rec or just a bad/broken wire in the loom .... Talking of points if you have access to a single cylinder dwell meter set the dwell angle to 22.5 degrees (rather than gapping) ... the motor will run well !!! but if you do not have access to a dwell meter you may find setting the ignition timing statically is better is better than setting the point gap & using a strobe to set the timing. if you need info on statically setting the timing PM me I'll knock something together for you

That is not odd .. just the way they were !!!! If you just need a barrel replacement do the following 1) find a Yamaha main switch that has the same amount of key positions 2) remove the 2 screws from the base and remove the base plate 3) check that the new barrel connects the correct wires in the correct switch position from your new base plate 4) If base plate is not avalible then wire the switch to suit .... in this instance I would guess the base plate will need to be modified (the AC & DC for some reason ran through the main switch) but to be correct it would not be difficult to do !!!

Hi Paul, I have spent the whole day with a 'lad' who knows 'whats happening' with his Jog .... it is very difficult to actually tell them what is going wrong as they do not tell you the full story but if the engine is flooded perhaps the auto choke needs to be disabled, throttle wide open, new plug or cooked plug, and turn the motor over it should start ... they always think the worst is wrong

You must remember the seller may have also asked the same question as you and also found no reply.... can you explain what 'my newly aquired dt is not running quite well,,' does this mean you are not going to tell us what is wrong ? Without that I would guess no one can help you ... it's like saying 'my laptop doesn't work' in a computer forum with no symptoms or background info

It would be nice to know if you get the bike to run !!!

As Yamaha supply engines to Malaguti it is not unreasonable for Malaguti to produce bikes badged Yamaha (as do MBK, Yamaha owned, and Rieju in Spain) it makes economic sense to build bikes in Europe to save tax/import duties but you do loose some quality for some reason. This badge engineering goes on all over the shop ... perhaps google Daihatsu Hijet & Piaggio Porter you will find it is the same van & the Daihatsu was built in Italy ... you just never know what you are buying

Hi Richard, back in the day when XV750's & 1000's were new they did suffer from a problem of the cylinder liner moving by about 1mm in its casting ... it gave an odd result ... the problem you describe (sort of running on one) and compression tests did not show any problem .. the fix was a very thin shim fitted under the head gasket. perhaps if some has had the motor to bits and not refitted the shims you may have another problem other than carbs

Hi Lenny a little more info would be good pictures etc .. but to be fair it's good to introduce yourself in the newbies area then post a question Regards Jim

Dating certificate ?? is that like e harmony for bikes

To Check the valve clearances do the following 1) remove the valve covers 2) remove the l/h engine cover (shiny one with Yamaha written on it) 3) using the 17mm bolt you can see turn the motor over until LT shows in the little window and both valves on the l/h cylinder are closed 4) adjust the intake valve to 0.1 mm clearance 5) adjust the exhaust valve to 0.15 mm clearance 6) turn the motor over until RT shows in the little window and both valves on the r/h cylinder are closed 7) adjust the valves to the same as the l/h cylinder but from reading this thread I guess your problem does not lie there ... Do your compression tests (both wet & dry) this will give you an idea on which part (if any) of the motor is failing if all is well turn your attention to the carbs & ignition timing

To check the charging system do the following in this order :- 1) Charge the battery 2) Check the charge rate should be 14VDC @ 5000 rpm if you get 14VDC @ 5000 rpm then replace the battery (job done) if not 3) Unplug the stator wires and check the resistance between yellow/black or yellow/red if you don't have yellow/black (+ve probe) and white (-ve probe) on Ωx1 if you don't get 0.4 ~ 0.6Ω replace the stator (job done) if not 4) Check for broken wires & bad earths (this means everywhere switches, indicators, clocks etc) No broken wires/bad earths replace the rectifier Yamaha, themselves, do not give read outs for the rectifier nor do they give a schematic of the internals of the rectifier so checking resistance readings across random pins is useless. After checking the wiring diagram for the 2003 TZR50 (I may be wrong here) it appears to be a DC mag as there is no voltage regulator as such. So I would guess the white wire supplies DC output from the mag to the rectifier (regulator) which in turn supplies a regulated voltage to the battery (via the red wire) & lights etc (via the blue marked L). the yellow/red (yellow/black) gives the mag the DC input it needs and of course the black (earth) which, if dirty or broken, could cause the battery to discharge The W/L (white/blue) and W/R (white/red) are ignition so can be discounted so I guess you are still clutching at straws Regards Jim

Just think a little bit more clearly .... you have a multimeter so perhaps connect everything up & start the bike ... check the voltage across the battery ... @ idle you should have battery voltage (may be slightly less if you are running the lights) then rev the motor & recheck the voltage across the battery which should rise to about 20% over battery voltage (14.5 volts (ish) if this happens the charging circuit is working fine (rectifier, VR & mag). Remember AC output from the mag needs to be converted to DC to charge the battery, so part of the rectifier will use a diode to convert the AC into DC hence the readouts from the rectifier. lecture over, I guess the problem you have is a faulty earth on the DC circuit which could encompass any switch or external earth to the wiring loom

ah but you have got me on the super dream .. so all power tools you need will be powered by a poo Honda & dependant of the job in hand the old 99'er dream may fail ... you have to remember those 3 valve heads and optimistic speedo's made the 250 market and to be fair the dream speedo may be slightly more optimistic than most

get a healthy super dream ... attach a rope to the grip at one end & the super dream grab rail at the other. Rev the nuts out of the dream drop the clutch and the grip will stay intact ... as the dream will stall but why not remove the l/h switch gear lift the edge of the grip with a small screwdriver spray wd40 underneath it and it will drop off the bars

you managed to get a ton out of a dream .. I guess you had a gale behind you (XS 250 the same) or it was being towed by an RD250 ?

oh a girllie dispatch bike .. saving grace light to pick up after the Volvo 245 DL knocked you off very easy to pick up !

You mean the spongy twin carb twin that would do 0~60 quicker than the CB250N but looked like a pile of poo ? CB175 - RD200 no contest best get the old boy to buy an RD200 (it has electric start) and just pee over those Honda things

I guess someone had to buy one what an awful tool (CB250NA) no go (same as XS250) but had that silly euro style ..... twin discs .. like wow did it need to stop from the heady speeds it was capable of