XJ550 with XJ600 engine.

Hi there everyone.

I've got a project 550 that had a seized motor, the person I bought it from had a xj/fj600 (3km/49a) engine. So I've fitted that using the 550 parts i.e. Carbs, intake boots, cdi/ignition Etc.
I've got the bike running quite nicely tbh but wondering would I need to rejet the carbs to the 600 engine as being for the 550 and if so what sizes main, idle etc... jets I would need.

Thanks

 

Why would you do that?--if it's a 600, jet it for the 600.

 

The 550 has small-ish carbs at 28mm. Do you know what size the 600 came with? Fueling is one thing, but making sure you get enough air is good if you want to maximize the potential.

 

FJ600 came with 32 and YX & FZ were both 30 mm.
Might be interesting to compare jetting amongst these bikes.
You said it was running pretty good with the 550 carbs.
Personally I would take some plug chops just to make sure it's not running lean.

The XJ650 and XJ750 use the same basic carb but with richer jetting for the bigger motor.
Same thing might apply here.

 

In which case I'd STILL go with the carbs that match the engine

 

Thanks for the replies yes I know it's about silly but the 600 didn't come with anything else so I just made it work with what was there. I don't want to buy a whole new set of carbs if I don't need to. If they are the same bodies just bigger jets I'll jet it for the 600. How do you find the appropriate size jets for the engine? Or is it just "guess work"

 

You have smaller throats so the 600 jets may not be ideal.
You might have the appropriate jets now. Plug chop.

Top end might not breathe well but probably pulls hard in the mid range.

 

xj600 uses bs32's mikuni's.
stu

 

Absolutely this.. Try it with BS28s first but keep an eye on the plugs -if it will pull to 100mph then I would say your good to go, any faster is tough work on these machines.Hopefully you still have the airbox connected. Swapping to BS30s would be the next step as they fit comfortably in the 550 frame/airbox but you may also have to change some of the rubber parts (I can't remember which it's been a while). BS32s will just about fit but you will need to use xj600 airbox rubbers and it's a very tight squeeze as the carbs are actually a fair bit bigger...

 

Got hold of some bs32's needed to use 600 rubbers in the 550 airbox. It's tight but they are in there. Just wanted to know what are the 2 air pipes inbetween the carbs are for/go to? Can I blank them off?
Thanks

 

Along with the ignition system for the engine.

 

the 2 "air pipes" are breather/overflow pipes ,there should be 2 black pipes attached that vent down to under the back of the engine. don't blank them off.
stu

 

Well sad news I lost my pride and joy In a fire at my workplace. On the look out for another xj 550 in the U.K. Not gunna be easy....

 

Sorry about your loss. Give us details on what happened.

 

How bad was the fire? I've seen some badly burnt bikes that have been restored.

 

It's just a bike....at least it wasn't a LIFE.

That being said, yes--it hurts when something material but special is lost, too. Been there--

During the first week of my senior year of college as a music education major with a concentration in low-brass, our music building went up in flames. We all lost everything other than what we had in our dorm rooms. In our case, we each had our own room in the music building, and that's were all our books, music, instruments, etc....were kept---4-5 yrs worth of learning and planning for the future......gone. Yup, it was just material stuff. Nobody was in the building, nobody got hurt.

 

The fire happened early hours of the morning, I haven't been down there to see what's left of the bike. I doubt there will be much left, the fire destroyed 6 other units on the site. Investigations are still ongoing but as you all say glad there was no people involved. Things can be replaced, life can't.

 

Was that the fire that was in the parking garage? If so, that made the national news here

 

No it was an incident in the u.k

 

Yeah... the one on the news said it was in the Liverpool area....near a horse track,...and apartment buildings----

 

the xj600 is much more plentyfull in uk.
stu

 

I doubt it, that one (1500+ cars!!) was in a multi-storey car park at Liverpool Arena. I guess once it started they couldn't risk letting people in to move the cars..

A bad day for the insurance companies.

 

Oh no this was at a small insustrial complex south of England.

 

Got some pictures of what's left quite heart breaking Defiantly won't be able to re use this...

 

Save the valves shims---/

 

Bloody Nora! The engine's formed a puddle of melt in pic one - that must have been some bastard fire!
Bad news indeed. They do come up on ebay, in fact there's a shiny one on right now sitting at 700 quid,

 

That was a very hot fire. The frame might be salvageable; as wall art if nothing else.

 

Almost brings a tear to my eye. What devastation. I would be worried about the heat changing the structure of all the metals including shims and frame.

 

Have you noticed how the fork sliders have simply 'disappeared' - along with the wheel! I think you can also make out clutch plates through the bottom of the melted sump - incredible.

 

Both wheels, carbs e.t.c everything aluminium has melted. Thought I could use the manifold but the clamps have melted aswell.. 1500 + degrees Celsius in there!
some of the cars we had in there.

 

This is soooo sad ...hope you had insurance and can find another xj 550

 

If you even find just a frame and good title to start with, we have enough parts through hoarders here that could outfit just about the whole thing.

I know I have some 55o parts that can send if you go that route.....

Anyone notice the missing engine mount-to-frame bolts in the third pic? How about where the wiring harness had been wrapped around the frame?

Seriously, though.....if you find a good frame, we got parts that can help you rebuild.

Dave F

 

^^^+1 that is the great part of this forum we try to help each other be it advise or parts