XJ600 engine in xj550 frame.

I've just fitted a xj600 motor in a 550 frame. Gonna use radian wheels, 600 forks, will put pictures up when finished, I know I need to use the CDI (black Box) off the 600, my question is will it just plug into 550 wiring loom and work, or do I have to change configuration of wires in the plugs. Any information would be most gratefully received.

 

With a paperclip you can pull the wire terminals out of the connector blocks and move the wires around if you need to.
Study the 2 wiring harnesses, it should work.

 

which 600 motor have you got? Early (separate alternator) or later (crankshaft alternator). As well as the TCI (it's not a CDI) you will
struggle to get BST32 carbs from the later bikes to fit with the 550 airbox. Search my threads for some guide on TCI wiring

 

UPdate - old thread here (very old..) https://www.xjbikes.com/forums/threads/another-tci-thread.47653/#post-423607

 

im working on a xj 5/6 but havent got as far as airbox yet...

 

Interesting - what wheels and swing arm is that?

Stock 550 carbs are BST28s, BST30s form the FZ600 are physically the same size BUT the BST32s used on the later XJ/FJ600s are quite a bit bigger, I think I managed
to fit them but with stiff airbox boots form a 600 also I mangled (temporarily) my hands in the process - and it didn't run anyway..

Since you airbox is missing it might be as well to go straight to pods. They do say though that if you can use the 'velocity stack' of the stock carbs rubbers it helps

 

Hi a100

Front end is gs500 with a bandit6 stem iirc... rear is gsxf750 rear wheel sv650 caliper and gsx750es swingarm. ..both stem and swingarm needed engineering shop ingenuity to go in so probably easier options out there. ..
I got 2 basket case xj600's cos I had an xj550 frame lying around and loada suzuki bits to make something with.
I'll start a thread on both soon so as not to jump on this thread any further but thought I'd show solidarity with the 5 to the 6...lol

 

Cool. I#ve a GS500 front end lying about - and a spare XJ frame (but no V5 for it..) GSX Swingarm transplant sounds a PITA but I've heard Thundercat fits if you want to go mono.. Yeah start a thread!!

 

I have a spare Radian yx600 frame with a v5 (practically the same frame as an xj550) that I'm planning building a cafe racer or a flat tracker out of, with a XJ600 pre divvy engine (£50 off eBay) with a gsx600f front end and gsx600f rear wheel.
The swing arm is where I'm struggling, yx600 swing arms are like hen's teeth to get hold of and expensive!.
Monoshock swing arms seem to long as I have already tried a 400 Bandit swing arm and it just doesn't lend itself very well.

a100man not to sure about a Thundercat swing arm as they quite wide at the pivot point, follow this link for some useful info regarding swing arms.

https://www.xjrider.com/viewtopic.php?t=3136

tobar how much needs maching off the gsx750es swing arm to allow it fit the xj/yx frame?

I will start a build thread once I get my Radian finiished.

Cheers lads

 

@tobar I really like the style of your xj, that's kind of the way I would like to go with my yx frame.

 

I run bs32s from an xj600 on my xj650, I ran them as originally jetted with pod filters and they ran fine - no flat spots I could feel.

 

I'd try (measure first) the S/A from an FZR 600. They're plentiful and cheap. Just weld on some shock mounts.
I fitted one to my much modified XS650 complete with linked mono-shock did that back in 2003/4
Cheers, 50gary

 

YX600 swing arms being box-section are in demand by people like me (XJ550) and also the XS lot as they are a direct fit for a number of the 80s bikes

So you could use an standard XJ550 swing-arm if you're in a pinch. The Thundercat reference was from a special that was documented in Practical Sportbike a few years
back. I think it had to be machined a little at the pivot point but not massively IIRC.

Cheers

 

@50gary an FZR600 swing arm would be a good choice, l would need to shave 20mm or 3/4 of an inch off the pivot point, have you got any photos of the XS650 for reference please.

@a100man I have considered an XJ550 swing arm but I'm not sure if I could squeeze a 140/80/17 rear tyre in. A Thundercat swing arm would look well trick, they are about 40mm wider at the pivot point.

Thanks

 

That's what I did, a good machine shop can do that operation. About ten MM from each boss. A horizontal boring mill would be the machine of choice.
Below is a way of getting the head tube welded accurately by double triangulation. This is a mock up of my system just to show the principle. I've lost most of my early photos
due to a photobucket screw up. I'll see if I can find a picture somewhere?
Cheers, 50gary

 

This is the XS650 with the FZR 600 Swingarm, Linked mono-shock, works like a treat.
I don't know if this will help, it's all I could find.
Cheers, 50gary

 

@50gary wow your XS650 looks really good and I can the engineering that went in to, great job. If my Radian cafe racer looks half as good I'll be happy. I'm interested what bike are the forks off, I would like to use blue spot calipers on my build.
Cheers

 

Thanks for the kind words. The Radian is one of my favorite bikes. I used Yamaha R6 conventional (cartridge type) forks. Although even then (2004) I had a set of USD
(Yamaha, R1) forks I chose the conventional because I felt they matched the tracker look better. There is nothing stock on that bike, it's quick and fun to ride.
No head shake rock solid, it has a thumb brake for the rear, linked suspension, 2/1 headers my build, RD 400 tank with completely new tunnel, shortened wheelbase,
all off the front, rear is longer with the FZR s/a, 24 degree rake, 50/50 weight dist., weight 360# semi rear-sets, TT seat modified, carbon fibre, with Suzuki SV tail light. ride height adjustable
rear shock, (my mod) 525 chain with offset counter sprocket, The exhaust is open, no baffles, the large diameter end and kick out are Sprint car pieces ceramic coated.
All my work, and it was my first bike build. Sorry to ramble on.
Cheers,50gary

 

@50gary that's a lot of work but it is really well finished and an absolute credit to you. Radian's are nice little bikes, not so common over here in the UK though, making getting hold some parts difficult. And I've got two!!, One will be as close to stock as possible, the other will be far from stock, a previous owner decided it would be good to chop the frame at the rear end.
Not sure what has happened to the photos I posted!!
Cheers

 

Beautiful bike. Lots of work into that.

 

Andy, re gsx750es swingarm

by memory...i had a round alu tube made for the swingarm pivot to go through as the swingarm is fork design this end..
i trimmed a few mm off the frame inner bosses carefully with an angle grinder and got this square much to my relief and to retain the end caps of the swingarm i remember having the innner shims of the caps surface ground ...

still need to get shock mounts welded on..its on my to do list

 

@tobar wow sounds an interesting project. I like the way you have engineered the swing arm. I mentioned in an earlier post that I have a Bandit 400 swing that I thought would not work so well, however I've had rethink and I'm going to try and shorten it, it's about 75mm or 3" to long. I'll post photos when I attempt this. Hopefully it should work well and it's steel so it'll be easy to weld.

Cheers Andy

 

yep done that...another xj im working on has a bandit 600 swingarm in it...
again i cant really remember exactly but it does need fettling to fit...possibly a bit off either side..i cut up a damaged and bent bandit 600 frame just for the lower shock mount and had it welded on to an xj600 frame..still work in progress but it works in mock ups...
its a bandit 600 wheel but for some reason someone put a 180 tyre on it..that will be coming off for a 160..gs500/gsx750f front wheel with axle same size as xj one...15mm from memory..but need to work out brakes or discs that will work with it..

 

going back to the gsx750es swingarm that may have had a bit trimmed off either side too???
but when it was fitted it was a bit stiff going up and down so the machine shop surface ground the shims for that reason to make it smooth...probably easier and cheaper than taking more off the swingarm..but i think originally that swingarm is 220mm, maybe 222 and with end caps 226mm wide so its close to xj5/6 frames

 

That looks good, I too have a B6 swing arm, again I thought it was too long however your set up looks fine. I also thought about a B6 rear wheel, they are cheap and readily available. The main reason I decided against a B6 rear wheel was the alignment of the sprockets. I don't know about XJ/FJ600 frames but there's not a lot of room on the Radian frame for the chain.

Cheers Andy

 

@tobar Again I'm not sure about pivot width for the swing arm of XJ/FJ600s are, but the Radian is 200mm. So that means getting creative with the hacksaw so I can use either a B6/B4 swing arm.

Cheers Andy

 

200 is that all..hmmm..what about original fireblade swingarm? off the top off my head 180mm width fork design at the pivot end so get a tube in the middle and sleeve the fireblade pivot down to use your spindle, space out the 180 to 200mm which should make chain run easier and maybe a slimmer cbr600 wheel spaced out....
is radian twin shock..may have to cut the brace off the arm if it is to get mounts welded on..if monoshock then that will need working out too

 

ps..thats me thinking out loud,,may work or may just be a load of bollox..lol

 

just looked on ebay
cbr900 swingarms are tubed at the pivot end not fork design and 50 quid and under...dont know what the spindle width is but just a bearing swap may work if the od and id works..
if you think it may work and cut off the braced arm to weld shock mounts on..i'll have the brace off ya..lol

 

@tobar No worries, I did think of a Fireblade swing arm, a bit extreme for me perhaps, although a good idea. And yes the Radian is twin shock which I would like to keep, maybe some XJR 1200 piggy back rear shocks just for the looks. I might have a look at the B6 swing arm again at the weekend.

Cheers Andy

 

well good luck with it all....as far as shocks go i'd recommend YSS twin shockers...so many different lengths,combinations and connotations in their catalogue at a good price and they look good to

 

isnt 200mm the same pivot width as rd350's..have a look at what swingarms they are getting put in those frames

 

@tobar this is a useful link https://www.xjrider.com/viewtopic.php?t=3136 although not a complete list. According to that list RD350s are 200mm at the swing arm pivot point and presumably RD250s would be the same.

Im sure I've seen somewhere of RGV250 swing arms used on RD250/350s.

The Radian frame is essentially a slightly modified XJ550 frame so it stands to reason that an XJ550 frame is 200mm at the swing arm pivot point.

YSS shocks do look good, I was thinking of using them but maybe a little longer for a nice stance, so that it looks like it's braking from 120mph even when it's stood still.

Cheers Andy

 

i'll try and measure up my xj550 frame with gsx750es arm which will be post modded of course....at the mo its buried at the end of the garage, im working daylight hours..and its snowing so wont be straight away

 

@tobar thanks mate, there's no rush and you never know someone might post the info here.

Cheers Andy

 

Yeah, well watch the steering angle if you go too far with that idea.

 

Thanks for the tip, however I won't be doing anything too extreme, maybe 20mm, it won't be like Motocross bike.

Cheers Andy

 

Check the rake (camber) angle 24* is the Sport Bike norm. Buell used to go to 23* SV650 25* old school bike 27* and more. Short S/A and slack rake was the rule of the day.
Modern is steeper, and longer S/A, just a few numbers for those that may be interested in how steep is steep? If you go too steep without a corresponding change in trail
you can get into oddball handling. Triple clamps on modern bikes typically have less offset keeping trail in proper range.
Cheers, 50gary

 

@50gary thanks for the heads up. As far as I can tell modern bikes have longer swing arms because they are mainly monoshock and need to be longer to allow space for the shock absorber. If I understand what you saying I could perhaps leave my Bandit 400 S/A stock and drop the forks through the triple clamps or yokes as we know them in UK and I could achieve somewhere near stock geometry or am I barking up the wrong tree.

Cheers Andy

 

the pics arent great but what they show is the alu needs cleaning..lol
so you have the centre tube made up to fill the gap
the frame inner bosses cut 5mm either side with angle grinder which worked out great taking my time..measure and mark out 10 times cut once
im sure this frame was 205mm at the pivot which i took out to 215mm as the ruler shows sort of
i think a gsx750es swingarm is 222m with cups...
the engineer guy took some off either side cos i remember him pushing the needle bearings into the swingarm a bit more..
the outer cups have been reduced and the cups have shims in them and they were played with to get a good swing..ground a bit flatter i think...
so not the easiest install but we got there

 

@AndyH64 ...^^ xj550 seca 4vd frame

 

@tobar the gsx S/A mods look like quite a bit of work, way beyond my pay grade. I've been gifted a GS500 S/A so I'll have a look at it when I get chance. I like the GS500 S/A because it is similar in appearance to the stock Radian S/A, albeit a little longer. I think it will look good and will suit the GSX600F (Katana for our American friend) rear wheel and twin shocks.

Cheers Andy

 

My 'pay grade' isnt great..lol but the engineer guy i know well and i think he's bemused at the stuff i dream up..lol
Gs 500 s/a with 600 wheel sounds good...easier to make shock mounts and get them welded on....consider a gs500 cush drive in 600 wheel for chain aligment if you havent already

 

"longer swing arms because they are mainly monoshock and need to be longer to allow space for the shock absorber". Umm, not really, the s/a is longer to help keep the front end down on the mega powered sport bikes and it makes them more stable as well. The front end of the wheelbase is shorter to load the front tire (more weight % on the frt. tire), steers more quickly, and to keep the bike's agility by maintaining the proper W/B.
Cheers, 50gary

 

@AndyH64 ..ive not had the shock mounts welded on yet but someone mentioned aluminium swingarms are probably anodized so use acetone to strip that off prior to getting them tig welded on...looking at the alu tube in the middle section which is bare and comparing to a 40 year old ish swingarm id say thats correct..
obv you wont have that problem with a gs500 arm..
but alloy (sic) me to throw a gsx750w swingarm into the mix...its alu i think with twin shock mounts and you could run a 150/160 wheel/tyre..bound to be cheap on ebay...the inazuma model...
i shoulda looked at that myself but even tho i was aware of it i stubbornly wanted to make the one i had work

 

Since when does acetone remove anodizing? In my 40+ yrs of welding I never heard of that.

 

@50gary

I stand corrected, thank you for your words of wisdom.

@tobar

I got a GS500 sprocket carrier with the s/a so I should be good to go on that front. Apparently the GS500 and earlier GSX600F's share the same rear wheel, I also have a length of 50mm X 25mm rectangular box section for the shock mounts, although I am considering a monoshock set up as the s/a has the dog bones and linkage with it, I would need a shock maybe an SV650 shock would do the trick.

Cheers Andy

 

@tobar Bandit 400 or RF400 rear wheels are a good choice 4x17 not too wide to cause too many chain alignment issues, I would have gone down this road, but I got both front and rear wheels off a GSX600f with tyres for the princely sum of £15 off eBay.

You may find this interesting https://www.customfighters.com/threads/90-yamaha-xj600-well-the-frame-is-at-least.111394/

Cheers Andy

 

@huntchucks

.. if youre aiming that question at me, i dunno cos ive never removed anodising..it was a recommendation from someone on another forum...i think he had 41+ years welding experience..


looking it up acetone doesnt get much of a mention unlike oven and drain cleaners if using household products...i will delve deeper

what do you use?

 

AndyH64... yeah use what you have and get the mounts welded on