FJ 1100 from 85 total resurrection

[Marqus]

Hi there,

I'm from Germany and try to restore a 85 FJ 1100. I am at a point where I really need help. I don't want to use parts from later models. So I am talking about the rear arm. If you look at the well known explosion charts, it is part 21 I am worrying.
Trying to find a bush with 25/20 diameter AND the flange ring (don't know the wird) is not possible.

Is there a way to use a needle bearing here? What would you do? What did you do?

Thanks a lot and greetings from Germany
Markus

[Pat Conlon]

Hello Markus, as you see, the 84/85 FJ's used bushings in the swing arm linkage. These bushings worked fine when kept lubricated but as soon as the wet weather arrived, or they ran dry, they failed quickly. Unfortunately these bushings are no longer available from Yamaha. You are left with 3 options:
1) Measure the old bushings and with a small tabletop lathe turn some new bushings out of Delrin (or similar material) I am not aware of an aftermarket bushing kit for the 84/85 FJ's. Please let me know if you find one.
2) Convert over to the needle bearings used in the '86/87 swing arm linkage. I have conflicting info on this conversion. Some have said that not a simple swap, that some machine work is needed to get the 86/87 needle bearings into the 84/85 links.
3) Ditch altogether the 84/85 swing arm and linkage and use the 88/89/90 swing arm that uses a dog bone style linkage. You will also need the '88-90 relay arm for the conversion. The hard points on your 84/85 frame will match up with the 88-90 linkage. No need to worry about appearance concerns, the 88-90 aluminum swingarm matches the 84/85.

Other folks please chime in....more info is needed on the needle bearing swap (option #2 above) Bonus points for pictures.
This question on the 84/85 swingarm bushings has come up several times thru the years...I don't think it's going away, so I would like to create a Suspension File on this subject outlining the options.

Welcome again Markus!

Cheers. Pat

[Urx]

Phosphor bronze bushes should be fairly easy to turn up even for a hobbyist lathe user
The stock material will feel pricey but should do the job easily if turned to reasonable tolerance

Swapping on a later 88-90 swing arm allows a 'buy and fit' approach without needing machine shop facilities but is a lot of expense when bushes wouldnt be that hard to do.

Just my thoughts

[FJmonkey]

If I have dimensions I can make Delrin/Acetal bushings. Or sintered bronze. Delrin/Acetal or UHMW would be better as they do not require lubrication.

[Pat Conlon]

That's a very nice offer Mark!   

[Marqus]

Thank you. Right now I´m trying to get some bushes/bearings here in Germany. I have sth in my head, still trying to figure out if it will work. I will make pics and tell you about it, once I finished.

Another "noob" question: There is a oil level switch sitting in the pan. Am I right, that this one is a real "level" switch? So when the oil level reaches a certain "lowness" a light will flash. If so, than this is no oil PRESSURE switch, right? Where would this one be?

thx

[red]

There is a oil level switch sitting in the pan. Am I right, that this one is a real "level" switch? So when the oil level reaches a certain "lowness" a light will flash. If so, than this is no oil PRESSURE switch, right? Where would this one be?  thx

Markus,

Yes, you have an oil level switch.  The light will stay on, when the oil level is low.  You may see the light come on during fast acceleration, on going up a steep hell, or those two conditions together.

You can install an oil pressure gauge, with the sensor in the correct oil passage.  We have work records of doing that project here.  It is a simple task, but the parts are costly.  People here (those who should know) will advise against having an oil pressure gauge, though.  The FJ has very little oil pressure at idle, and this reality will worry you needlessly.  You do not want to know.
   

[Pat Conlon]

Heh heh, I remember the first time I saw that red oil level light blink on...I thought it was an oil pressure light, yikes!

Freaked me out....

[Marqus]

Ok, thanks for the information, especially the fact that the oil pressure is so low, that it is better to not have a pressure switch is new for me and very interesting.

Another question coming up. I am working from the engine over the rear wheel and axle bearings to the rear arm and frame. So I will do the whole front part in the next weeks. I always have problems when it comes to the forks or better to the disassembly of the forks. Had quite a few breakdowns trying to do it on my GPz in 2020.

I have not checked or tried it yet, but is there an easy way to tear the fork parts apart? Will I have to build a tool with a lets say 19mm nut, to open the connection in the lower end of the tubes?

And after 78tkm would you think the whole fork parts (bushes, gliding-stuff) will have to be replaced (as a MUST)?

And another question about the piston rings. Do the gaps have to look towards a certain position as on 2-strokes? Or is it just important that they do not line up? You know what I mean? maybe the gaps should be looking to the front on 10 and 2 o'clock?

Thanks for any help!!

Markus

[Motofun]

Ring gaps should be staggered.  no particular required orientation as there are no ports to interfere.

[fj1289]

Markus - in the Files section there are many good writeups from many members with great info.

Here is a link to one for front forks: https://fjowners.com/index.php?topic=1911.0

It is labeled as cartridge emulator installation - but is very detailed at disassembly of forks and tools to be made.   It would be a huge improvement to not only rebuild the forks, but to restoring them and install the RPM valve assembly too.

[Pat Conlon]

FYI, RPM also has the 27mm damper rod keeper.



http://rpmracingca.com/proddetail.asp?prod=27mmForkHolder&cat=54

Yes, if you are going to replace your fork seals (use oem only) go ahead and do the bushings while you're at it.
Your 1985 fork springs were weak the day they left the factory in Iwata, and 37 years later they are certainly sacked by now, go ahead and invest in new fork springs, and even better yet, some RPM fork valves to go with those new fork springs.

You know you want to....

[Marqus]

Oh my...I am far away from understanding what you were writing about right now. Hopefully it's getting clearer when opening the forks and reading your link. Thanks!!

[Marqus]

Another thing: my brake pedal leaves scratches on the clutch cover. I don't think I am the only and first who has that problem. Is there a common solution or an easy work around?

[fj1289]

Sounds like the bike has fallen on that side at some point and bent the brake lever.   You will have to bend it back out.  I suggest mounting the clamp end in a vice and gently bending it back out a little. 

Depending how deep the scratches are you might be able to sand them out and polish the cover again.