AUSXS250RK Posted December 24, 2012 Share Posted December 24, 2012 Folks, Anyone out there run across dual front disc brakes fitted to the DOHC XS400s? I have run across two PICs of such setups. One of a GREY bike and one of a RED bike. These appear very similar to the items on the Yamaha XJ650L Turbo model, but use polished lower forks instead of the black paint finish on the turbo. I have a DOHC XS250, which is due for a fork restoration - rechrome and new seals, so may be time to consider a possible upgrade. The PICs are interesting, as they appear to be production or pre-production items.They have slotted rotors, which I have not seen on production bikes of this era, and many did use the same disc.They also have seat straps, which usually indicate a Japanese market version. I also have a 1982 XZ550S, which runs dual front discs, same calipers but different lower forks, which have the axle mount offset, so no swap possible, and they are not common either. The XJ650 turbo appears to be more common, at least in the USA. The DOHC XS 250RK (19Y) model (SECA) was sold in Australia in metalic BLUE and RED versions in small numbers, and seemed to have vastly outsold its XS400 sibling. it was only sold in the Australian, New Zealand, Ireland and Venezuelan markets, if the parts manual is to be believed. - Yes I do have an original parts manual for the 19Y model. The SK (Maxim / Heritage ?) chopper style XS250 model is even rarer here in Australia. I do not think the 1982 RJ/SJ models ever made it here though. My interest came from looking for spares for my XS250RK - as many parts are common to other models - and the XZ550 and XJ650 turbo are the only bikes that had the same dual /four spoke cast alloy wheels as the DOHC XS250/400 (SECA) model. - John. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted December 24, 2012 Moderator Share Posted December 24, 2012 you need to use the xj550 fork lowers or font end. this chap in Germany did it http://yamaha-xs400.de.vu/ guy from Netherlands did it (from xs400.com) Front brake: easy conversion. I just swapped the lower forklegs with a pair of XJ550 items and installed 2 calipers from an XV920. Brake cylinder is from a CBR600 with comfy adjustable handle. Standard front rim takes 2nd disk with no mods. Link to comment Share on other sites More sharing options...
AUSXS250RK Posted December 24, 2012 Author Share Posted December 24, 2012 Drewpy, A big thanks - The German website looks good. - I will have to translate into a doc off line to get all the detail. I have looked at XJ550 items on Ebay, but most seemed to be only single disc legs. I will keep looking and check local wreckers too. This version will save me removing black paint - but I would have to clean them up anyway. I have an extra disc, from when I imported a S/H front wheel from the USA. My front wheel was starting to corrode, time spent out in the rain.Too many winters parked in the street, while I was at work.My original disc got chewed up by an after market set of 'metal' pads - I do not recommend them.It just got deeper and deeper grooves cut into it, and lost probably 30% of its stopping capabilty. The metal is good though - only very minor surface rust after 20 odd years of just sitting around. There maybe enough left to get it reground flat again, if not there seem to be plenty of the original items still around. I am chasing the rotor bolt lock tabs - be nice in 304 stainless. Ever seen the slotted rotor versions ? The LH caliper should be common to some other models too. A Merry Christmas to all - John. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted December 25, 2012 Moderator Share Posted December 25, 2012 I wouldn't have the lock tabs in stainless, its the wrong steel for bending. you can still get them from yamaha or try HVC cycle. I think the slotted disks was off the ypvs 350 but can't remember if they fit or not! Link to comment Share on other sites More sharing options...
dt502001 Posted December 25, 2012 Share Posted December 25, 2012 If this help or not ? but the seca 400, 550 were both sold here and lots of parts for them in the wreckers and the front wheel from a seca 400 fits in a ypvs 350 1983 front end,so I can't see why the rz front end wouldn't fit, might have shorter top tubes? Link to comment Share on other sites More sharing options...
AUSXS250RK Posted December 26, 2012 Author Share Posted December 26, 2012 Guys, Thanks for your comments. The RZ350L appears to have a different casting around the axle clamp, and larger fork dust seals. I may be a possibilty. The PICs I have seen are on the motorcyclespecs.co.za website. The grey one is under XS400r and is of good quality/resolution. It appears to be a match for the XJ650 LJ/RJ turbo, as the disc has paired slots in the rotors. The XJ550 option may be a possibilty, but like the XZ550, I suspect most did not have the dual front brake setup, so may be difficult to find. The XJ650 LJ/RJ turbo still seems like the best option, as it did use the same cast wheel as the XS400. I can only conclude this from seaching the parts ilustrations, which can differ from actual production items. Off topic slightly - A couple of Questions on the DOHC XS400: 1 - Does the DOHC engine have bearing wear issues ? My DOHC XS 250 version used to have fine metallic particles around the sump plug, in the oil, when ever I changed the oil, which was at 1500km intervals, with filter change every 3000Km, or every 2nd change. Not something I was ever happy about - but it was fine from 14000, to 45000 Km , when I stopped riding. 2 - It used to stall after high speed riding (100km/hr), say on a freeway section, and coming back to slower speeds at lights - just did not want to idle. Did not happen too often, but it was annoying. Usually came good after a few minutes. I was not sure if the fuel cock lost vacuume, and switched off, or the ignition coils were cutting out for some reason. They do have a 20 sec or so time window for starting after which they will turn off. Something to keep in mind if having to push start. - John. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted December 26, 2012 Moderator Share Posted December 26, 2012 i would say the carbs need cleaning as they don't like the modern fuels and easily gum up. there's a few guys from aus on www.xs400.com who may be able to help with regional stuff for you Link to comment Share on other sites More sharing options...
AUSXS250RK Posted December 28, 2012 Author Share Posted December 28, 2012 Drewpy, My performance comments relate to when I was riding - late 1980s - on Super leaded fuel. The carbs wil definitely be gummed up by now, having sat around unused since 1991. Here is Aus, there is not a mandatory ethanol mix in petrol. It is available, mainly on the upper east coast, where the cane fields give a ready supply of sugar to produce ethanol. I guess there are plenty of other additives in there though to replace the lead that was removed, so your comments are probably correct. I have joined the XS400 site. It has grown since I last looked. Still think I had a lean out problem after hard hot running. The plugs never seemed too hot though. The bike could always pull hard right up to its 10500 rpm redline. I would like to get the bottom of the wear issue however. Parts for this 250cc engine are very hard, if not impossible to find. - John. Link to comment Share on other sites More sharing options...
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