Trokel's XJ900 thread - and other bike stuff

edit 26/9/13 - Seeing as I posted this in the general thread I have decided that I will also include the other bike related stuff that I have been up too in here as well.

My plan is for this to be an ongoing thread that details all aspects of my XJ900 including everything from the mechanical stuff to some of the rides that it goes on
I will provide details of the work that I am doing to it so that I may get advice and feedback from the vast knowledge of everyone out there and hopefully give back by documenting some of the problems that I encounter and how they were solved.
SO PLEASE FEEL FREE TO RESPOND WITH YOUR COMMENTS AND WORDS OF WISDOM AS YOU SEE FIT

Lets begin with a brief introduction.

Recently I bought an 83 model XJ900 which a few of you will have seen in some of my other posts. It is a very tidy looking bike that seems to have had quite a bit of time, effort and money put into it as well as some very unique modifications. For quite some time I was looking for a cheap (under $1K) early air-cooled Japanese bike of any brand around 750cc with minimal fairing as a bit of a project and I was planning to travel a reasonable distance for the right bike. Then I saw this one in the local paper and even though it was a lot more than I was planning to spend I decided to check it out and instantly fell in love with it. So that was that I had to have it.

 

Re: Trokel's XJ900 thread - a work in progress

When I looked at it the main faults that I noticed were all 3 brake disks were too thin, the rear tyre was perished and there was some minor oil and fuel leaks but other than that it started, ran and rode very well.
So once I got it home I began to work on resolving these faults and also carried out a bit of servicing as it seemed to be a bit lacking in that area and that's when I started to notice a bigger problem that I had missed.

 

Re: Trokel's XJ900 thread - a work in progress

Well? Don't leave us hanging. What's the "bigger problem?"

 

Re: Trokel's XJ900 thread - a work in progress

Metalgear sell the discs. Is your frame cracked under seat?

 

Re: Trokel's XJ900 thread - a work in progress

Dayam! That is a sleek bike! Please don't leave us hanging!

 

Re: Trokel's XJ900 thread - a work in progress

This is precisely why I hate the Aussies...they have all the best stuff!
Really HOT women...The best RX-7's I've ever seen...and nothing but really cool bikes!
I really don't hate the Aussies...I guess I really just envy them!
Cool bike!

 

Re: Trokel's XJ900 thread - a work in progress

You are correct on one account. Metal gear do sell disks and that is what I ended up buying



But tell me more about this cracked frame issue, is that a common problem? Is this something else that I should check for and if so where exactly?


And in reply to the other responses - Sorry for leaving you hanging, but as I said this is a work in progress so I can't reveal it all in the first 2 posts.
But just to keep you interested here is a picture of how it looked last weekend

 

Re: Trokel's XJ900 thread - a work in progress

In response to a question in one of your prevoius threads, that is an XJR petrol tank, and it holds 21litres.
Nice bike you've got there, how about an FJ1200 3CV front end upgrade?
Here's one of my XS1100's with an XJR1200 petrol tank and FJ 3CV front end.

 

Re: Trokel's XJ900 thread - a work in progress

From what I can gather the bloke I bought it off did very little by way of maintenance to it in the 2 or 3 years that he owned it. It seems most of the work on it was done by the previous owner before him and when it comes to appearance they did a very good job.
For those of you that haven't picked it yet it has had an XJR1200 tank custom fitted to it because the original XJ900 tanks have a tendency to rust out. This may not sound like much but in order to make it fit correctly it has had custom made brackets welded to it and special infill sections added to the side covers to fill in the section where the original tank used to go. Also the seat has been cut down so that it doesn't look out of place where it meets the tank. All in all I think it is a very nice job that looks like it was meant to be that way and not just some thing that has been slapped together to make it work.

 

Re: Trokel's XJ900 thread - a work in progress

Nice looking bike. Thanks for the info.

What are the main benefits of the XJ1200 front end :?:

 

Re: Trokel's XJ900 thread - a work in progress

Re the frame. They are known to crack where lower frame spar meets seat loop. Examine closely. Not serious though and easily welded. I like the shocks on that bike. I wonder what brand they are? The uni joint has been known to fail but not common. You mentioned it had an oil leak. That's unusual and was perhaps a clue to your later major surgery?
Where are you by the way?

 

Re: Trokel's XJ900 thread - a work in progress

..and crack in other places, i have read of a few variatons on th theme here, it's worth a careful look around. My new toy has a crack parallel to th frame on inner side of side stand mount, it kinda looks like a fault in th tubing.

 

Re: Trokel's XJ900 thread - a work in progress

The FJ has got 41mm diameter forks as opposed to the XJ900's 37mm. The 900's front brake calipers are twin piston like an early FJ11 or 12, but the later FJ's are 4 piston calipers.
I think the front wheel on the 900 is 19inch though could be wrong, and the FJ is 16 for the 11 and early 12, and 17 for the later 12's.
An XJR on the other hand has got 43mm forks with a 17inch wheel and 4 piston calipers.

 

Re: Trokel's XJ900 thread - a work in progress

Gosh that's beautiful. What kind of a rack is that? I hadn't imagined a 900 could manage a rack and still look so elegant...

 

Re: Trokel's XJ900 thread - a work in progress

That is a nice looking 900. 8)
Check for the cracks / previous repairs , my 5 bikes all have them.
So where abouts in NSW are you ??

 

Re: Trokel's XJ900 thread - a work in progress

Looks like I better do a frame inspection while I have got it apart.
The rear shocks are SHOWA brand. They have a model no marked on them however I can't remember it at the moment but if want let me know and I will check for you.
As for the oil leaks the main one was from the antidive units which was an easy fix. There was also a bit of a leak at the rear of the head where 2 small nuts had come loose but that seemed to stop once I nipped them up.

As for me I am located in the Albury area.

 

Re: Trokel's XJ900 thread - a work in progress

While carrying out my initial service I discovered that it had different spark plugs to what the manual recommended and also one of them was different to the other 3. 8O



At the same time I figured it would be a good idea to do the valve clearances and as it turned out some of them were well out of spec.

 

Re: Trokel's XJ900 thread - a work in progress

Not sure what brand the rack is. I picked it up for $20 and then I custom made the mounting brackets to make it fit how I wanted it.

 

Re: Trokel's XJ900 thread - a work in progress

Looks like a gearsack copy. Gearsack was a very popular aussie made rack for many years but for some inexplicable reason you can only buy the bags now..

http://www.gumtree.com.au/s-ad/australi ... 1005464059

 

Re: Trokel's XJ900 thread - a work in progress

Alright
I probably need to speed things up a bit so that I can get to the point that the bike is currently at.
But first -
So I did the valve clearances and replaced the spark plugs with the ones the manual recommended and took it for a spin. It ran like crap. Seemed to be misfiring once I got to around 4500rpm. It was at this point I thought that I should have a go at doing a carby balance. (this was something that I had never done before).
So after a bit of research I bought a Carbtune Pro and this is what I found.


But Before too long it looked like this


But of course in order to do that I needed a YICS Blank off tool and here is the one I made out of a piece of steel rod and some brass tube that I had.

 

Re: Trokel's XJ900 thread - a work in progress

As it turned out the main problem with the misfiring turned out to be the spark plugs that I put in. The plugs specified in the Manual were resistor plugs but after doing some tests I discovered that my bike has resistor caps installed so once i fitted some non-resistor plugs and it ran like a dream.

 

Re: Trokel's XJ900 thread - a work in progress

OK so now I will get to the main problem and I would really like to hear some other peoples thoughts on the subject

Some of you will already know this as I have made mention of it in other threads but the issue is it is burning engine oil and a lot of it. When I test rode it I checked for signs of exhaust smoke but obviously not well enough. Admittedly the smoke became much more noticeable after i did the oil change. I wasn't going to worry about it for a while but after recently doing a 450KM+ ride I realised that it is too bad to keep riding it that way. Recently I bought another motor and carbies for it and have begun fitting them but I would still like to work out what the problem is with the original motor and fix it up.
It doesn't seem to be a problem with the valve stem seals as it only really blows smoke under hard acceleration.
I did a compression test prior to removing the old motor and these were the results.
No.1 = 120PSI
No.2 = 120PSI
No.3 = 120PSI
No.4 = 128PSI
While not great the above readings are still in Spec as per the manual, which made me start to think that the problem might be with the oil rings more so than the compression rings so I removed the barrels and here is how it looked.





It has been a long time since I have done anything like this with an engine but to me it looks like the oil rings pictured are too compressed and would not hold enough tension against the bore.
THOUGHTS ANYONE

 

Re: Trokel's XJ900 thread - a work in progress

From what I understand it has been rebuilt before but it appears to still be the standard bore. What are the chances that a new set of rings will solve the problem and what other things should I be checking for?

 

Re: Trokel's XJ900 thread - a work in progress

Definitely find a bore gauge and check cylinder taper , top to bottom, side to side. Measure the pistons and see if they are in spec also.

 

Re: Trokel's XJ900 thread - a work in progress

nice bike!!

 

Re: Trokel's XJ900 thread - a work in progress

Make sure the ring lands are not flogged out. If the rings flop around in the grooves you will use oil, and it wont be fixed by just replacing the rings.

Top ring clearance should be 0.03 - 0.07mm
2nd 0.02 - 0.06mm

 

Re: Trokel's XJ900 thread - a work in progress

Never used one of them before, will look into that a bit more.

I imagine that this can be easily checked with a feeler gauge.

Does anyone know where you can get O/S Piston kits for these bikes? :?

 

Re: Trokel's XJ900 thread - a work in progress

Please keep the suggestions coming

Meanwhile here is how the rest of it is coming along.

The other engine is now in the bike but I can't do much more with it until my gasket kit arrives from chacal as I need to fit new gaskets to the engine side covers and intake boots.

 

Re: Trokel's XJ900 thread - a work in progress

So while I am waiting I thought I should check out the carbies that I got with the other motor.
I would have liked to use the original carbies that were on my bike but they are different because it is the 853cc motor and the new one is an 891cc.



Now these carbies were supposedly rebuilt so I wasn't going to strip them down but I am glad I did because they were quite dirty inside.



As mentioned in many of the carby threads on here, I too had a lot of trouble getting some of the float pins out. 8O I tried heating them with a butane torch and cooling them with freeze release spray but nothing seemed to be working and I was getting quite concerned that I was going to end up breaking a post off. Then I noticed in my tool kit a small pair of end cutting pliers that I had sharpened up years ago for some electronics jobs and they seemed to be the perfect thing to get a grip on the head of the float pin and as a result I was able to remove the pins quite easily.

Notice the blocked main jet on the left hand side

 

Re: Trokel's XJ900 thread - a work in progress

The parts from chacal arrived today and they all look spot on. I must say It was a pleasant surprise to see them so soon, it took about 11 days. I didn't think I would get them until the end of next week. At first I was reluctant to order parts from overseas but after getting stuffed around for about 3 weeks trying to buy the gaskets locally I thought it was my best option. Obviously I bought more than just a gasket set. I was quite amazed at how extensive his range of parts are.

Looks like I'll be busy on the bike this weekend.

 

Progress report

I got a lot done on the weekend. So here are a few more pics.
Should have it going again this week.

The Carbies cleaned up alright. Did a bench sync using a thin strip of plastic then hooked them up to some fuel and checked the float levels. Had some trouble with no.4 flooding so I pulled the needle and seat out and re-cleaned it then tweaked all the floats a little and it was all good.



As I mentioned earlier I didn't buy just a gasket set from XJ4Ever. Some of the extra things that I got was a new set of carbon brush's for the alternator and the starter motor. I figured that they were pretty easy to replace while I had it apart and they didn't cost that much. Its a small thing but will help keep it reliable.



And here is how it looked by the end of the weekend. Had a little bit of trouble refitting the carbies. When I went to hook up the throttle cable I found that the little pivoting bracket that it connects to had dropped down and gotten wedged against the back of the head so I had to undo them again and pull them back out of the intake boots so that I could get it free. Lesson learned. Still a few small bits to be done before it is ready to fire up but its close. All in all the engine swap has gone fairly smoothly with no real problems.

 

Re: Trokel's XJ900 thread - a work in progress

So here it is all back together. I really liked the black motor but the silver one looks pretty good also.


Apart from a different wiring connector for the alternator the 891cc motor was a direct replacement for the 853cc.

Here's how the carby balance looked when I first fired it up after the bench Sync. Not too bad.



After a bit of fine tuning I took it for a spin. It was running OK but not quite as smooth as I would like. So I decided to recheck the valve clearances to see how they had settled in. As it turned out 3 of them needed adjusting again. While doing this I also found a problem with the cam cover gasket so i have temporarily fitted the one from my old motor to keep it going.
Once that was done I balanced the carbies again and checked the exhaust temps.
They all looked pretty even.

 

Re: Trokel's XJ900 thread - a work in progress

Wowzas. Looking good; the XJR tank looks like it was made for the bike.

 

Re: Trokel's XJ900 thread - a work in progress

Looks real good Trokel,interesting idea with the exhaust temp.Real head turner that bike.Tidy as.

 

Re: Trokel's XJ900 thread - a work in progress

It does suit it quite well and seems to confuse a few people also. So I have just fitted some XJ900 decals to the side covers to help clear up it's identity crisis.

gunnabuild1

I have read a few posts in other threads where people have talked about certain cylinders running cold or not firing so it got me thinking.
We have a hand held thermal imager at work that we use on electrical switchboards so I thought it might be interesting to check the exhaust temps for evenness given the work that I had done to the carbies.[/size]

HERE's a bit more on how it is progressing
I did a plug chop on it at around 4200rpm when I first got it running again and it seemed to be a bit lean to me.


The carbies that are on it at the moment are running stock jetting but the bike runs a very open 4 into 1 so I have ordered some different jets and a colourtune plug through Len so i can play around with it a bit more. Initially I had the pilot screw set at 2.25 turns but I have now changed it to 3 which seems to have improved the idle mixture a bit but I will check that further once I get the colourtune.
But in the meantime seeing as I had a ride planned for last Friday I decided that I would make a custom baffle to restrict the exhaust a bit to see if that helped. Here's how that turned out

First I found a bit of scrap aluminum that I had lying around and whacked it in my trusty old lathe.


Then after a bit of cutting, shaping and polishing I turned it into this.


It turned out better than I had planned and actually sounds better as well. Not quite as loud but still has a nice throaty note. So with that done I chucked the missus on the back and took it out for a spin.

We did a nice little 140km loop through the hills and it ran like a charm. I still reckon it is running a bit lean though so I will play around with it a bit more when my parts arrive and post details of how I go with it.

 

Re: Trokel's XJ900 thread - a work in progress

Great looking bike trokel. I am rather partial to the silver motor, I think it breaks up all of the black, and provides contrast. Those engine covers are in really good shape too. As for the lean issue on the mains, have you considered shimming the needle? The plug color is not very far off at all, and an upsize on jets might be a bit much.

Cosmetically, I think is would be really sweet if you could find headers in black chrome like the midnight maxim's had.

 

Re: Trokel's XJ900 thread - a work in progress

Did you source the Carbtune Pro in Australia or UK?
Nice ride BTW.

Cheers
Phil

 

Re: Trokel's XJ900 thread - a work in progress

I haven't really considered that for this bike. I know that some bikes like my old XR have adjustable needles and needle shimming is a common thing for KLR owners to do but I have never played around with them myself.
I might have to look into it a bit further.
Does shimming the needle provide a more subtle way of enriching the mixture?

 

Re: Trokel's XJ900 thread - a work in progress

I Bought it direct from Morgan Carbtune which I think is in the UK. Just went to the website to research them and ended up buying one.

 

Re: Trokel's XJ900 thread - a work in progress

The needles on the Mikunis have three grooves cut into the top of the needle to allow for fine tuning of the mixture. You move the little circlip to adjust the mixture, top groove = leaner, bottom = richer. To access the needles, you remove the top hat, withdraw the slides and remove the two small phillips head screws inside at the bottom of the slide, then take the needle assembly out and adjust. I,d certainly try that before changing the jets, cheers, Murray

 

Re: Trokel's XJ900 thread - a work in progress

Possibly a dumb question, but how do you achieve the exhaust temp graph. Is that part of the Carbtune Pro Kit?

Forget that, I just reread the post and found th answer!!!!

Real sweet looking bike

 

Re: Trokel's XJ900 thread - a work in progress

Cheers,
Thanks for that. I noticed the 2 screws and plate in the slide when I cleaned the carbs but didn't bother undoing them at that time as I didn't see any need for it. I just assumed that the needle in these wasn't adjustable.
As I mentioned earlier this motor uses the BS36 carbs which have a 107.5 main jet as standard. Out of curiosity I opened up the BS35 carbs from the original motor which I can only assume had been set up for that exhaust and found that they had 114 main jets fitted which is a big jump from the 102.5 that was standard for them. The old motor ran really well (apart from the oil use) but it did seem to be a bit rich when I checked the plugs however those carbs had been flooding as well so I just put it down to that being the problem.

I just want to make sure that I get it right as I don't want to damage this motor as a result of being to lean.

 

Progress report

It's been a while so I thought it was time for an update. (to be honest I have been busy working on my project boat)

Since my last post I have raised the jet needle one notch and upped the main jet to 110 but still can't seem to get a plug colour that I am happy with. I have also done a colourtune to set the pilot screws which as it turned out needed to be wound out quite a lot to get a satisfactory mixture.
I think I still might have to play around with the float levels as per my other thread here - http://xjbikes.com/Forums/viewtopic/t=40285.html

However it does seem to be running reasonably well at the moment so I have taken on a couple of decent rides to test it out in a range of conditions to gauge the overall performance and fuel economy.

Here are a few ride pics

At the Eastenders Rally for the Griffith Classic Motorcycle club



These next ones are from a 2 day ride where I took the missus away for our Anniversary. This was a really good test for it as it was 2up through the mountains with extra luggage on board.

On Mt Hotham


And Falls Creek




I was quite happy with how the bike performed although it seemed a bit down on power once at altitude. Guessing it may have been running a bit rich with the thinner air in the mountains.

 

Re: Trokel's XJ900 thread - a work in progress

Trokel,

Nice. Very nice indeed.

Gary

 

Re: Trokel's XJ900 thread - a work in progress

Love this thread.

 

Re: Trokel's XJ900 thread - a work in progress

Thanks
Its good to see that other people are enjoying it.

I must say that for the money I have now spent I was beginning to think that I should have bought a newer bike and just gone riding. But now that my hard work is beginning to pay off I am really glad that I didn't. I feel so much more attached to this bike because of the work that I have put into it and it is a great feeling when other people take an interest and comment on how nice the bike is.
It has given me a greater appreciation for the other bikes that I have seen at the classic rally. Unfortunately there weren't any XJ's there but one of the bikes that impressed me were the 6 cylinder Honda's.



I can only imagine what it would be like to rebuild and balance 6 carbies.



Here in NSW a bike has to be 30years old to be eligible for classic rego so mine is close but not quite there yet. But who knows maybe in a few more years I will get to see a few other XJ's at the rallies.
Now that I am hooked on these bikes I am on the lookout for another XJ if I can get it cheap enough. One that I can try and restore as an original looking bike.

 

Re: Trokel's XJ900 thread - a work in progress

Trokel,

Nice thread and....yeah, somebody was bound to ask. Doesn't having that sticker there prevent headlight illumination?

Gary

 

Re: Trokel's XJ900 thread - a work in progress

Yeah,
I thought it was a bit of an odd thing to do but it was only temporary and I guess I didn't have to stick it on the headlight but I just copied everyone else. We took them off once the ride was over. Some of the stickers had different color dots on them which was use to define the bike categories for judging at the end of the ride.

 

Re: Trokel's XJ900 thread - a work in progress

Doesn't present any problem if you only ride during the day......

dave

 

Re: Trokel's XJ900 thread - a work in progress

After getting home from a 3 day ride on the KLR last weekend while I was parking it in the shed I noticed that the XJ was leaking oil from the left fork leg. It was quite a bit of oil which seemed strange as there had been no signs of weeping prior to this but either way it looked like I was going to have to replace the fork seals so I decided to strip down one of the spare fork legs i had to have a look at what type of seals they used.
As it turns out I also have a set of forks of an 85 model so I started thinking that I might use them instead and do away with the antidive and air adjust so while I was at it i pulled one of them apart and began to compare the 2.




There are a number of significant differences one of which is that the 85 model forks are 15mm shorter in overall length but use a heavier spring. With the heavier spring they wouldn't have as much static sag so I doubt that the height difference would matter but i was wondering if anyone else has tried this on their 900 and if so how well did they work?