83 vs 84-86 model XJ900 parts compatibility

I have an 83 XJ900 and am looking at buying an 84 or 85 model for parts and was wondering about the compatibility between the 2. I know the later models have the 891cc engine whereas mine is 853 and according to the specs the carbies are a different model which had me wondering- :?:
Are the heads the same?
Will the later model barrel and pistons fit my motor?
In general are most of the engine parts the same?
What is the main difference between the carbies?
What about the shaft drive and running gear?
From what I can find in the manual I assume that the brakes and wheels are the same.

Are they compatible enough to make it worthwhile or should I look for an 83?

Thoughts please

Cheers Troy

 

I think most of the running gear is the same. Hopefully others will be able to comment re engine compatibility. Possible spares bike here:

http://www.ebay.com.au/itm/320934850204 ... _500wt_922

 

That is the one I have in mind at the moment. I wonder if it is someone on here who has bid on it?

 

Interesting question.
I'm in the exact opposite boat as you: have '84 and '85 model XJ900 (s) and a spare '83 motor.
I'm hoping the heads are the same, but will find out one day when the '83 motor gets stripped before step below.
I eventually plan on having the '83 barrels bored out to fit the 85 pistons (and new OEM rings that I got cheap on Ebay!)

Chacal may be the man with this type of knowledge.

 

Shame that you are so far away. We may have been able to sort something out.
Still it would be good if someone could shed a bit more light on the compatibility question.

 

What about doing a part number comparison? Can't remember the relevant site but it has been posted before by somebody...

 

http://www.yamahapartshouse.net/pages/O ... MOTORCYCLE)/CARBURETOR_(XJ900RK_-_1983)

You need a parts look-up site like this that works in Australia.
Only the '83 was sold here, so it doesn't list the big bike.

 

Best bet would be to ask Len Chacal at info@xj4ever.com

He's got the scoop on things like that.

My PERSONAL understanding is that the bikes are identical, other than that the engine was punched out for a few more cc's for the later bikes, and the fairings became a frame-mount rather than a handlebar-mount. Pretty much everything is the same.

Obviously some parts are missing on the bike shown, and the exhaust is not original.

Dave Fox

 

I was outbid. Someone got a good buy though. I would have bid more but by the time I allowed for the cost of freight or travelling to get it I couldn't justify it.
So I will have to keep looking.

In the meantime I will contact Len to see what i can find out.

 

Same here Trokel, I was bidding on this bike also, for parts I needed for my motor. I wasnt prepared to go too high ,as it looked as it had spent a long time outside ,with a lot of corrosion around the aluminium. So no telling if the motor even turned over. It was an 1985 xj900n by the way,not an 84 Cheers ,Murray

 

Forgot to mention, from what I recall, without running down to the shed to measure, the diameter of the combustion dome in the 891cc motor , is 1 or 2 mm larger, and has a different part no. stamped on it , Cheers ,Murray

 

That would make sense. But I wonder how much difference it would make.

Your right about the corrosion, it looked OK from one side but the other looked pretty bad. Also the fact that they had never had it running means it may have had serious problems to begin with. Will keep looking and hopefully I will come across an 83' somewhere. At this stage I am mainly looking for a motor but it is always handy to have a spare bike.

 

Trokel , I may have given you mis information on the sizes of the head combustion dome . I did the original measurements before I decoked the heads. Just out of curiosity I put them side by side and measured them, the results a) no discernable difference in the dome diameter between the two, b) inlet ports the same size , even though the 891cc carbs are a slightly larger throat. So ,at first glance they seem to be much the same, though the 853 head is marked 3ALOO ,and the 891cc is marked 3ALO1. Hope this helps , and sorry for any confusion, Murray

 

I was under the impression the two 900 mtrs had different cranks, the later being slightly longer stroke.
I only have early 900 mtrs so cant compare.

But according to this site its just the bore:
http://www.xj900club.nl/uk/technics/specs900/

 

The 853cc motor runs a 67mm piston , while the 891 is a 68.5mm one .and the stroke is the same on both motors. The carbs on the 891 have a slightly larger throat. The 891 also has a 6 spring clutch instead of the 5 springer on the 853 ,apart from that they,re pretty much the same, as far as I can tell .cheers, Murray

 

How about this guy...seems to have a number of xj900 parts incl motor. Maybe he is somebody on this site? Lol

http://www.ebay.com.au/sch/chiantus_max ... 4340.l2562