UFO Posted December 20, 2008 Share Posted December 20, 2008 Hello all, I am new to your forum and new to yamaha's, I already have a couple of harleys, and have now decided to build myself a chopper / bobber out of a xs 650, ....I am looking at getting a donor 650 and probably get a new rigid frame, using the donor bikes engine forks wheels etc,.. I have located a 1977 xs 650 B but have yet to see it, is the B model any different to the ordinary xs 650 ?....is there anything I should look out for mechanically ? .........are they a strong engine ? .......one last question , are they kickstart only on that year ?. sorry about throwing all these questions at you, as a newbie, .. but I would be greatfull for any advice you can give me. UFO Link to comment Share on other sites More sharing options...
JimR Posted December 21, 2008 Share Posted December 21, 2008 Hello all, I am new to your forum and new to yamaha's, I already have a couple of harleys, and have now decided to build myself a chopper / bobber out of a xs 650, ....I am looking at getting a donor 650 and probably get a new rigid frame, using the donor bikes engine forks wheels etc,.. I have located a 1977 xs 650 B but have yet to see it, is the B model any different to the ordinary xs 650 ?....is there anything I should look out for mechanically ? .........are they a strong engine ? .......one last question , are they kickstart only on that year ?. sorry about throwing all these questions at you, as a newbie, .. but I would be greatfull for any advice you can give me. UFO Hi UFO, XS650b does have a kick and electric start, the engine was well reliable I managed 100K miles on my 79 XS650s without it comming to peices. The most unreliable part was the starter motor drive gear they only lasted about 10k each, but as the starter motor was an after thought it comes of easy and the hole blanked off which removes the problem (excuse the pun). Regards Jim Link to comment Share on other sites More sharing options...
UFO Posted December 21, 2008 Author Share Posted December 21, 2008 Hi UFO, XS650b does have a kick and electric start, the engine was well reliable I managed 100K miles on my 79 XS650s without it comming to peices. The most unreliable part was the starter motor drive gear they only lasted about 10k each, but as the starter motor was an after thought it comes of easy and the hole blanked off which removes the problem (excuse the pun). Regards Jim thanks for the info Jim, I am really looking forward to doing the build that 650 twin sure is a good lookin g motor. UFO Link to comment Share on other sites More sharing options...
JimR Posted December 21, 2008 Share Posted December 21, 2008 thanks for the info Jim, I am really looking forward to doing the build that 650 twin sure is a good lookin g motor. UFO Hi UFO, If the motor has been looked after I doubt you will need to touch it but if you do things to watch for are making sure the roller bearings on the crank fit on the dowels else they will spin in the case (easy to miss these, but not to bad to fix if its got wrong, bar another engine strip). Make sure the castle nut holding the ATU to the end of the cam is well tight, if it comes loose it is possible to damage the cam beyound service, the little pin tends to shatter the cam ! Things to look for on the engine are if on start up from cold the motor badly rattles for 10~15 secs this is a worn out cam chain (even tho the adjuster has loads of adjustment left) not to bad to fix bar having to take the motor out of the frame. The B modal you are looking at shared most parts with the S modal I had back in the late 70's/mid 80s, and in the 100k odd I had it I had very little go wrong with the cycle parts, from memory I shimed the swing arm twice, replaced the rear shocks once, 3 sets of chain & sprockets, loads of tyres & brake pads. My S version only having a single disc up front where as the B had a twin set up. Regards Jim Link to comment Share on other sites More sharing options...
UFO Posted December 21, 2008 Author Share Posted December 21, 2008 have spoken to the seller now , and yes the starter has been taken out and blanked off, thats no problem... the bike is apparently a good runner, but a bit scruffy to look at, and at 30 years of age I think its entiteled to be. have now purchased it over the phone and with photos over emails,....so watch this space. UFO Link to comment Share on other sites More sharing options...
JimR Posted December 21, 2008 Share Posted December 21, 2008 have spoken to the seller now , and yes the starter has been taken out and blanked off, thats no problem... the bike is apparently a good runner, but a bit scruffy to look at, and at 30 years of age I think its entiteled to be. have now purchased it over the phone and with photos over emails,....so watch this space. UFO be nice to see some pics Regards Jim Link to comment Share on other sites More sharing options...
UFO Posted December 21, 2008 Author Share Posted December 21, 2008 be nice to see some pics Regards Jim will post some pics when I get it home , and hopefully all the way through the build, ... I was telling my mate that I was just buying a old yam, he replied 30 years old thats still a new un, but then he does ride a 1941 harley wl 45. and that is a beauty. UFO Link to comment Share on other sites More sharing options...
UFO Posted December 22, 2008 Author Share Posted December 22, 2008 well I just got the xs 650 home , and it turns out it looks better than I thought it would, it runs ok apart from a slight missfire on the lefthand side,... whilst ticking over fast it misses and pops from the left hand pipe a bit, which is funny because another xs that I went to see the other day did exactly the same...is it a common problem ? any ideas..... UFO Link to comment Share on other sites More sharing options...
JimR Posted December 23, 2008 Share Posted December 23, 2008 well I just got the xs 650 home , and it turns out it looks better than I thought it would, it runs ok apart from a slight missfire on the lefthand side,... whilst ticking over fast it misses and pops from the left hand pipe a bit, which is funny because another xs that I went to see the other day did exactly the same...is it a common problem ? any ideas..... UFO When new this would signify the dwell angle/timing set incorrectly but as the bike is now a wee bit older the carbs maybe at fault. Start with setting tappits,timing/dwell and carb balance if that fails have the carbs off & cleaned. I assume the bike has plenty of performance (can accelerate from 30mph in top with no probs & at 70 the engine running at about 4750k rpm and a max of 100mph) Regards Jim Link to comment Share on other sites More sharing options...
UFO Posted December 23, 2008 Author Share Posted December 23, 2008 When new this would signify the dwell angle/timing set incorrectly but as the bike is now a wee bit older the carbs maybe at fault. Start with setting tappits,timing/dwell and carb balance if that fails have the carbs off & cleaned. I assume the bike has plenty of performance (can accelerate from 30mph in top with no probs & at 70 the engine running at about 4750k rpm and a max of 100mph) Regards Jim have got it home now and started stripping it ready for the start of my project, have only rode it down my road as it is not insured etc,.... it accelerates 1st 2nd & 3rd ok thats all the road I had , it has been fitted with electronic ignition and appears to start 1st or 2nd kick no problems the missfire was not major you just noticed that when it was ticking over fast the left pipe would pop every now and then,on stripping the bike down I noticed that the exhausts were very loose and blowing a lot, the carbs were flooding as well as falling off. so that might be part of the problem.. onwards and upwards from here on I hope. UFO Link to comment Share on other sites More sharing options...
UFO Posted December 23, 2008 Author Share Posted December 23, 2008 well here she is, not to bad for 30 odd years old. UFO Link to comment Share on other sites More sharing options...
jeepurz Posted December 24, 2008 Share Posted December 24, 2008 looks like a good donor, check your valve clearance, timing , carbs,, bout 1st. toss that elec as far as you can, tuned right itll start right, and without elec youll keep it tuned right. not sure where your located but if you need frame help yell.prob point you somewhere in the us or uk. Link to comment Share on other sites More sharing options...
socalyamaha Posted December 25, 2008 Share Posted December 25, 2008 the 1975 xs650 is the B model the 1977 xs650 is the D model FYI no major differences. but i think the front brakes were different. Link to comment Share on other sites More sharing options...
UFO Posted December 28, 2008 Author Share Posted December 28, 2008 well I have had a few hours spare in the last few days and have done a bit more on the XS, stripping the components from the bike was straightforward as I thought it would be. But stripping the several coats of very badly applied brush paint from the cases was not so easy, I polished them after stripping, the barrels and crankcases come up ok, but the heads are quite a rough casting so I thought I might paint the heads black and leave the rest polished. ( must try and find some pictures of other bikes done that way so as I can decide if I like it or not) still the project is now started......UFO Link to comment Share on other sites More sharing options...
UFO Posted January 11, 2009 Author Share Posted January 11, 2009 well I have managed to do a bit more, and its starting to take shape....... the tank is only sitting on top in the picture, and once I had removed the old xs tank brackets it now sits a few inches lower and slightly further forward..... Link to comment Share on other sites More sharing options...
UFO Posted January 24, 2009 Author Share Posted January 24, 2009 A bit more progress has been made, as hopefully the pictures will show I have now fabricated the mudgard, battery box, seat mountings, sissy bar (not sure if it needs a sissy bar or not, its only there to stop my sleeping bag from falling off )also a fake oil tank for the electrics......the rear tire is a avon sm mkII 500 x 16 but it is not on the correct rim yet, I wanted to keep the brake drum on the rear and are having a 16 x3.5 built along with a 21" for the front....sure are loads of little bits left to fab, buts its all good fun. Taz Link to comment Share on other sites More sharing options...
gabby Posted January 24, 2009 Share Posted January 24, 2009 ufo,,i notice you have a battery box on there,, have you thought of running it batteryless?? im in the process of building one not unlike yours but i got an rd350 magneto, which with a little modifying to the backplate fits straight in, basic chop wiring, regulator from a z750, its got points and a capacitor to replace the battery, havent finished it yet but it should work i think... certainly leaves the frame looking less cluttered,, gabby Link to comment Share on other sites More sharing options...
UFO Posted January 24, 2009 Author Share Posted January 24, 2009 ufo,,i notice you have a battery box on there,, have you thought of running it batteryless?? im in the process of building one not unlike yours but i got an rd350 magneto, which with a little modifying to the backplate fits straight in, basic chop wiring, regulator from a z750, its got points and a capacitor to replace the battery, havent finished it yet but it should work i think... certainly leaves the frame looking less cluttered,, gabby funny enough me and my mate were talking about the battey on my xs just tonight,....but I have decided to leave it in, it doesn't look to bad,..Ihope. Link to comment Share on other sites More sharing options...
gabby Posted January 24, 2009 Share Posted January 24, 2009 funny enough me and my mate were talking about the battey on my xs just tonight,....but I have decided to leave it in, it doesn't look to bad,..Ihope. looks a damn sight better than mine, at the mo i've still got the mag wheels on it , trying to source a pair of spoked drum brake wheels but they seem to be scarce. trawling ebay etc to try and keep the cost within a budget but i'll bide me time till i get them.. when i got it it was complete, at least it looked complete, but everything was painted red?? on the strip down i found at least half the bike was bodged together, stripped threads etc, apparently the bloke lost interest.. he'd have been better leaving it in bits, i mean who the hell puts the carb intakes on a bike with metal glue?? personally i prefer to use bolts lol good luck with the build,, i'll be keeping an eye out for the photos of the finished article. Link to comment Share on other sites More sharing options...
UFO Posted January 25, 2009 Author Share Posted January 25, 2009 looks a damn sight better than mine, at the mo i've still got the mag wheels on it , trying to source a pair of spoked drum brake wheels but they seem to be scarce. trawling ebay etc to try and keep the cost within a budget but i'll bide me time till i get them.. when i got it it was complete, at least it looked complete, but everything was painted red?? on the strip down i found at least half the bike was bodged together, stripped threads etc, apparently the bloke lost interest.. he'd have been better leaving it in bits, i mean who the hell puts the carb intakes on a bike with metal glue?? personally i prefer to use bolts lol good luck with the build,, i'll be keeping an eye out for the photos of the finished article. when I picked mine up, I thought the same as you ,...this bike is complete and up together..but on stripping it down, there had been a lot of bodging going on, still I didn't need most of it....yep you could be right about the wheels being scarce,..Ive seen plenty of mag wheels for sale but not many laced wheels, rebuilding is not cheap either... have you been on either of these forums they are both quite good..........http://www.britchopper.co.uk/forum/ or http://www.thechopperunderground.com/forum...ex.php?act=idx.. Link to comment Share on other sites More sharing options...
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