xj598

Eh? Crankacse breather connects to the air box and that's the only route for oil. which I guess could be 'burping' up if too full. Does this 'oil' smell of petrol - if so it could be overflow due to stuck float or , old, hard needle chamber o-ring, or knackered float needle.

If I can find the right size I'll sen you one free! e.g a pack of 10 viton o-ring 1.5 mm c/s x 40mm Id is about a fiver - just need to know the size a bit more precisely - but that is indeed the rub. J

Thanks.Fair price for the kit - but plenty for a 50p o-ring..

..for petcock to tank seal on 1980s XJ series (550/650 etc). Anyone know ? Quicker/easier (and cheaper) than buying an oEM I would hope. Viton better than Nitrile ? Cheers J

Ended up usig a 15% concentration of phosphoric acid after cleaning the loose stuff out with a handful of screws and diesel - seemed to work well.

Yes, I did the nuts and bolts in the tank thing before the electrolysis (the bike was in bits for 14 years before Imade my foolish ebay bid - the power of nostalgia !). In fact I've opted for phosphoric acid which is a widely used rust treatment/converter so we'll see how that goes. The stuff I ordered is 85% concentrated but I read 10% is still Ok for this purpose so I'll be diluting with distilled water I think. Cheers J

Thanks for the replies.. Compression tested ok after I had reassembled - only one pot which had suffered water damage was down to about 135. Anyway went back to it tonight to check float levels ( a bit low but not too bad) then I drained the carbs fully ( and noticed some slight debris) and swapped back to my aux tank. Now it starts (!) a bit rough mind you but at least I'm back to where I was. Last year I tried some electrolysis on the tank which worked but probably not well enough. I'll get some brick acid at the weekend and give it a go with that I think.. Cheers J J

Well, they were 'quite popular' in 1981 when I bought mine. If I recall Coburn and Hughes in Luton had a load and sold them with free insurance for the first year. I think mine cost 500 quid. After a few months I was cut-up by a cattle truck and bent the forks which pretty much wrote it off IIRC. I kept it though for a while and fitted some forks/wheel from any early RD200 that had twin leading shoe brakes - that looked way cooler than the enclosed forks and single leading OEM stuff. I sold it to my mate several tears later havinmg never rode it with the RD set-up though. TBH it wasn't much slower than the RD but you had to lose the 'ape-hanger' bars that it came with.. As a side note I saw a guy at the TT last year riding one he had from new - a red one he still had the OEM bars..

Ok so here we are as promised in teh 'Introduce yourself' section.. I had the XJ598 running up the road in the last couple weeks for the first time following a basket-case rebuild and was pretty chuffed. but now it simply will not start. I rebuilt the top end with new rings set valve shims etc.. before instaling the motor so I'm reasonably comfortable with those mechanics. I also have the correct TCI for the Radian pick-ups and I'm getting a spark. When I initially tried the motor with XJ600 (BS32) carbs it wouldn't start for love, money or Bradex easy start. I then fitted the 550s BS28s though and all went well - for a while and as said I even manged some forward motion... I have since also tried starting it from my auxliary tank but zippo. Ideally I need some FZ600/Radian BS30 carbs, but I'm struggling to see why it now won't start on the BS28s (which have been well cleaned BTW). It does start on a few breaths of Bradex so I'm sure it's a fuelling issues. I will likely pull the carbs again to check levels,jets etc.. again but if anyone has another suggestion I'll gladly hear it... Cheers J

Hello all New boy with new tale of woe - hope it's not bad form to start this way.. I have in my brothers shed an Fz750 (88 vintage) that has MOT and runs well and an XJ550 with a Radian engine (XJ598) that doesn't (well not often). There's a GS500 waiting to be turned into DualSport too but that's another story. I'll continue the 'woe' in the workshop section.. Cheers