Yx600 engine fitment in 550 frame

Does anyone know whether there are any fitment issues with the late model radian 600 engine in a 550 frame? I read that the alternator was relocated to the side of the engine in 89.

Thanks

 

The Radian is essentially a model that was built from XJ550 parts. The main differences are in the bodywork. The XJ550 and Radian have always had the alternator behind the cylinders instead of on the end of the crank. There is at least one thread here about the swap you are looking to do.

 

Gotcha. I had the same impression, one article I read must have been feeding me the wrong info. I'll be getting the whole bike so I'll be looking to mount the dual disk front end and swingarm on the 550.

 

Keep us informed..and pictures please|

 

The engine will physically fit I'm pretty sure of that, but you are correct that there was an engine change in the 600 at that time (we also see it in the XJ600 of the period that was sold in Europe). The ebay listing here shows the later motor and you can see the cover which is usually over the pickups on the LHS is a different shape and underneath there are alternator coils (I have two of these motors for spares). I didn't look further into where the ignition pick-ups come from in the later model. but they will likely require a different TCI.

 

Thanks for the info! Luckily it doesn't look like it will have an effect on fitment as you mentioned. I'm buying an entire bike so assuming the tci is still on it I should be okay. Are you running stock 58.5mm pistons in your 550/599 or have you bored it out? I'm strongly considering going all out on this engine build, if I am able to find pistons that will allow me to punch it out to 652 I just may.

 

Mine is a standard (early)Radian I actually bought it by accident but it worked out OK. Note that you don't get a tacho drive in the 600 engines so you will have to fit electronic or go without. Finding O/S pisons is tricky. At some point someone was looking at Kawa z650 pistons as an option (62mm) to make 672cc - questionable though if the liner can take it..

 

Gotcha, yeah unfortunate about the tach. I don't mind the look of the radian gauges so I may see if I can somehow get the gauges mounted in the Seca instrument cluster. Yeah 672 may be a tad aggressive. I plan on doing a lot of research and if I can find larger pistons then great, if not the stock 600cc engine is a boost in power regardless so I guess I cant really lose!

 

Here's an fz600 tach in the 550 cluster..

http://xjbikes.com/forums/threads/electronic-tacho-in-a-550.94297/#post-523404

 

Also check what carbs you have with your Radian BS30s fit easily in the 550, BS32s don't..

 

Thanks for the link! That looks quite nice. Were bs30's not standard on the radian? And just to clarify, when you say they don't fit easily in the 550, do you mean in the frame? Thanks!

 

I was wondering if thr later (89/90) Radians used BS32s (like the Euro XJ600) which are physically bigger. On reflection though I think it's highly unlikley. BS30s fit fine as they are the same size as the 550's BS28s you can even use the same airbox rubbers but intake rubbers must be from a Radian.

 

It's possible! Thanks for all the info, hopefully picking up the bike tomorrow and then I'll know for sure!

 

Sorry forgot to answer this one.. Th BS32 rack is wider across the frame and the carbs are longer from airbox to intake. If you get a set of XJ/FJ600 airbox rubbers (that suite BS32s) you will see that the outer two are 'cranked' to accommodate the wider rack. With a lot of sweat tears, silicone grease and a hairdryer I did get a set of 32s in the 550 frame and connected to the standard airbox - the 600 rubber fit rather miraculously. Problem is I could never get it running. In retrospect I think my carb cleaning might not have been up to scratch back then (about 1 year -18 monthsago..) but I since got a set of 30s which slot in and out a lot easier. I may be down on power but it's quick enough..

 

So I picked the radian up on the weekend, $400 and a case of beer. The bike itself is a mess, but the parts I want (Dual disc front end, engine and swingarm) are all in good order. Engine only has 16'000 km (10k miles) on it. Cleaned the carbs yesterday and she fired right up, even rode it around the block! Amazing how much low end grunt this engine has compared to the 550, pulls harder at 4000rpm than my 550 does at 6.

Compression is great too, 140 psi across the board. Next step will be to pull the engine and begin disassembling it.

 

Looks good to me - wonder what tank that is - doesn't look Radian..

 

The guy fiberglassed over the original tank lol, it's a mess.