Fork Swap on 750 Maxim

A post by Alive on another thread gave me this idea. It's not much of a mod, but it might make life easier in the long run.

On my 650, the front blinkers were swapped by some PO with blinkers from a Virago 1100. This turned out to be a great improvement, since they fit and have "running lights".

My XJ750J Maxim - the '82 model - has a set of forks that are pretty difficult to work on, according to the Haynes manual. Anything that involves a propane torch to disassemble a part seems pretty screwy to me.

I'm still a ways away from having to worry about this, fortunately, since the bike has a LOT of restoration needed before I get to the forks. However, forks are expensive, so...

Does anyone know if there are forks from another bike, such as an XJ 900, that might be a straight across swap for the 750 Maxim forks (no anti-dive on this model)? It would be well worth the money to have parts that are easier to maintain and don't require welding gloves...

Thanks in advance for any advice.

 

Well, actually you can use a heat gun also, the idea is that they want you to expand the very top of the lower (outer) fork tube so that the split-ring guide bushing that is inside of it (below the oil seal) can come out easier, BUT................


I don't think that's actually necessary on the XJ750 Maxim models. Once the damper rod retaining bolt at the bottom of the tube is loosened, there's nothing to prevent you from withdrawing the chrome upper (inner) fork tube from the lower fork tube, since the 750 Maxim models did not use a split-ring bushing on the bottom of the inner fork tube, like some other models (550 Maxim, 650 Turbo, all 700's, 750 Seca, 900RK, and 1100's) did. On those models, the split-ring bushing on the bottom of the inner tube will try to "expand" outwards and will interfere with the removal of the inner tube from the lower tube, as this expanded bushing on the bottom of the inner tube interferes with the bushing at the top of the lower tube. Then you have to use the upper tube as a "battering ram" to actually pull the inner tube bushing past the lower tube bushing, sometimes actually pulling that lower tube bushing out of it's saddle in the process.

In that situation, the heating of the upper section of the lower tube makes things easier, as the aluminum expands and makes the split-ring bushing at the top of the lower tube "looser" (it's in there really, really tight) and thus easier to get past or extract as you batter-ram the inner tube bushing past it.

But 750 Maxims do not have this split-ring bushing on the bottom of the inner tube, and the last one that I took apart was as easy as any other fork to dis-assemble that doesn't have the split-ring bushing on the bottom of the inner tube..........

P.S. it's not only Haynes that mentions this heating trick, so does the factory Yamaha workshop manual for the '82 750 Maxim...............monkey see, monkey do?


By the way, ALL lower tubes have a split-ring bushing at the top edge (just below the oil seal), and truth be known, they really should be replaced when rebuilding forks. But they're generally not available (well, not yet!) and they are a beast to remove on the non-inner-tube-bushinged models.

 

Len,

I'm constantly amazed by your knowledge and ability to explain the intricate details of all the XJ bikes.... This site would be lost without you.

Thanks for all your help.

 

Hey Alive, you're surely welcome!

And I'm still constantly amazed that Yamaha didn't make that red-white-and-blue XJ900 model available here in the good ol' USA.......I mean, what could they have been thinking?

 

It's crazy... I think they would have been a real hit over there... With the colours and the power... It's still my daily ride and I love it.

 

My apologise Rhys for going off topic.

 

You tell me.

What really grinds me is that we only got ONE YEAR of XJ900s, those guys down under got what, like 15+ years?

 

Not only that, but the next year the motor went from 853 CC to something like 892 (?) for the next 18 years, so we got the wimpy 900.

Rhys, the '83 XJ 900 USA model had anti-dive, so unless you are getting a later 900 front end from Europe or Aus/NZ and spending HUGE for shipping. . .

 

The exchange rate is in your guys favour at the moment so thinhgs like shipping are probably a little more affordable

 

I'm looking at the Haynes manual. I don't see anything about using a propane torch to remove the forks...

(skips a few pages forward)

...oh, removing the seals... gotcha. If it helps any, I had zero trouble removing the seals on my 750J, and a torch was NOT required. In other words, the Haynes manual lies.

I wouldn't sweat it.

 

Well, I guess I'll just have to try it then!

I have plenty else to do to the 750 before I need to worry about the forks, fortunately. It would be nice to have fluid in the front brakes, for instance. Also, I will likely have rebuilt two sets of 650 forks before I get to the 750 forks, so I won't be a total newb by then.

Thanks for all the advice!

This won't be the first time the Haynes manual has lied to me. There are supposedly some errors in the carb section as well, and the descriptions in the electrical sections are *accurate*, but take some work to properly match up their descriptions with the diagrams. :/