A little bit of this and that, mostly YOUR help. :)

Hi guys,

Im the proud owner of a XJ 550 Seca from 82, a european model, Im from Denmark.

I have a few questions I hope You can help me with.

1. Is it possible to convert the rear brake from drum to disc, if so how ?
2. If any of You have converted the front forks to usd, is it then a direct fit, from wich model. If not, whats the mod, to make it fit ?
3. Is it possible to tune up the engine, how ?
4. Has anyone wired up a Motogadget M-Unit ?

If this post is totally of charts, please send me in the right direction.

Thank You - Have a nice ride.

 

Greeting , to convert you would need to find a bike set up with disk as donor would be easiest way, One thing as to "tuning" check and adjust valve clearance, you will possibly need to resynch carbs. ( you may need to take carbs to church of clean..go to xj4ever on upper rt corner of page he sells all the parts you need as well as his links are great ) Check plugs /gap . These are a few thoughts...more to follow ...

 

Hi Jetfixer - Thx for the advice, will check xj4ever.

Do you have any suggestion for, witch bike could be a good donor. I guess its more or less the swingarm, and tubing i need ?

Should maby have mentioned, that I already have changed the oil, oilfilter and plugs - But afterwards, I have thought of using iridium plugs(if they come for this model), not the most important thing right now.

Looking forward for more cool advice.

 

Stick with normal plugs. The spark plug is a tuning component in the TCI ignition system. Fancy spark plugs don't improve things, and can sometimes make the engine run worse.

 

An 86 to 87 Yamaha Radian is a good donor swap the forks and triple tree over...it has dual disk so you will need the master cylinder as well. As to switching to rear disk and swing arm ...WHY? I you put the dual disk on it will improve braking. Just thought of something a Radian wheel is shorter others have swapped to this set up search threads on it. Not sure if these bike made it to europe or not...what is your budget$$$$ ??? Agree with kmoe stock Ngk plugs ...all the way. Good luck

 

Another +1 for ngk plugs, in my (albeit limited) experience, they just preform better.

 

Thx for all the inputs - My budget is not the biggest issue, its my first real(I would say serious) build, so the budget will be set after, what Im aiming for. Not to sound arrogant or nothing, its just that I love the XJ 550, the bike has a sentimental value for me, because my cousin owned one, sadly he died by suicide in 2001. We had a close bond, but I have never got the chance to tribute him, witch I would very much like to do with this bike, now I have the chance. He was the type, who had many crazy ideas like a build like this. I remember he told me once, that it would look cool with rear disc brakes on his 550. That was back in 1999, cant even imagine what a challenging job it would have been back then, well thats why Im asking, and want to make this change.

So Im sticking with the NGK plugs, that good to have in mind, so this I wont even bother changing.
Will check if the Radian i available in DK or maby DE, SE or the UK, it would be strange if there isnt a EU model of the radian we will see. If not, would it be possible to put on a R6 front from a 01 ? Can get one for free for this build through a local salvage yard(he normally only get cars in).

 

You won't find that Radian thing in SE, think it's an american model. R6 front end, probably not a direct swap but it can be made to fit it's just a matter of money and effort....

 

"the budget will be set after"
I like the way you think. Find out how much it costed, and then decide that was the amount you wanted to spend!

 

There is a thread (maybe two) here about how to do a R6 front end swap. There are also other front end swap threads, as well as a thread on building a Hossack-type fork.

 

Thats also, why Im asking here. Im in a research fase. But still the cost is the least right now.

 

Either get a different wheel and swingarm, or machine and weld.

Either way, you will spend time and money for very little practical effect. XJ rear brakes are perfectly adequate, and front brake is 80% of your braking anyway.

Someone has, I've seen pictures.

Converting forks is easiest when you have steering stems close in dimensions. There are also bearing kits to adapt different diameter stems.

Same way you tune up any carbureted engine - clean and synch carburetors, adjust valves, replace/clean filters, change oil.

I'm not sure we have that in the States. What is it?

He is asking about USD forks. That's "upside down".

His 550 is Euro-spec, so it already has dual disks and Radian forks will not make any difference.

 

@JPaganel, and all others - Thank You for Your great answers, so far.

I have tried putting up link for converting forks from other bikes, and the M-Unit, but without any luck - Got a spam warning. Now I have sent a message to admin. :/

Allright, so about the rear conversion, from drum to disc brake, actually wont be that great an idea, unless I find another swingarm or do a bigger mod job.

My conclusion for now is then, that I will concentrate of what I have now. The M-Unit, and the USD fork from the R6. If there is time I will pick that one up in the weekend at the salvage yard.

 

I think there is someone who did an m-unit install. Do a google search with site:xjbikes.com after your keywords.

 

The m-Unit is an electronic device aimed at cleaning up the electronics and also functions as a fuse block.

Yousef, there is a restriction on posting links until you have made at least 5 (I think) posts. You should be able to post them now.

 

http://www.allballsracing.com/index.php/forkconversion

https://revivalcycles.com/collections/featured-products/products/motogadget-m-unit-controller

 

Worked like a charm - Thank You.

 

The M-Unit, and purpose, I think, is a must, with especially older bikes like the ones most of us inhere have.

 

I see the M-unit as an option, not a must (there are disadvantages to processor-controlled power management, just as there are with traditional fused systems). IIRC to use one on an XJ requires a fair amount of rewiring since it has a common positive feed to all branch circuits.

 

Found out, that I either can use a swing arm from a GS750 or a XS500 if I want rear disc brakes. Ofcause with some modification.

First fase of the build is to change a few things I think, so that I can ride this summer. Will change the seat and modify the rear, to make the seat fit, and install the m-unit.

Will take some photos, through the process of installing the m-unit, and modified rear.

 

That looks fancy. Can't think of a single reason why I'd need it.

No, really. If I was building a totally custom bike and was creating a wiring harness from scratch, I might use one. If I had an extra $300 to toss at it. As it is, I think it's inviting more trouble than it will fix.

$15 for a new fusebox and $5 for a box of fuses will take care of your electrical gremlins. Relays do go bad on occasion, but can be replaced by $5 standard relays with a lot less work. It's not often you have to replace them, either. Out of the last half-dozen bikes I worked on only one needed a new relay. A fusebox install I can swing in under 45 minutes. This thing would take a few days.

 

I'm beginning to understand how my father felt when points ignition became "obsolete" and he was listening to me go on-and-on about the advantages of electronic ignition.
Funny thing; I have a few engines that use points ignition, and love them for having it.

 

I have no special love for points.
No special hate, either.

Neither points nor electronic ignitions have ever given me trouble enough to get soured on the entire concept.

I'm fine with electronics - I have delved into the innards of TCI boxes and replaced components. I think electronic ignitions are more useful - no adjustment needed, they just work.

I do kind of hate carburetors. Especially setting floats.

 

Here are a couple of links from a member that installed the Motogadget:

http://www.xjbikes.com/forums/threads/relays-or-not-to-relay.72383/

http://www.xjbikes.com/forums/threads/xj650-brat-tracker.71544/page-2#post-513268

 

I have a few older outboards that I maintain. I prefer the units from the 60s with points over the "newer" late 70s and up motors with the CDI ignitions. Reason being, when a magneto/points ignition comes out of adjustment or needs service, it is a slow decent into non-function- one cylinder may start to foul plugs, or misfire at high RPM, etc. Very, VERY rarely does it just quit out of the blue. Conversely, when one of the CDI boxes fails (and they DO) you go from happily motoring to panicked paddling. And let me tell you, I'll take pushing a bike over paddling a stranded boat any day! Oftentimes, simple is better.

 

I carry a spare TCI whenever I'm more than an hour from home.

 

I swapped my front end to a GSXR750. It was fairly straight forward. The stem dimensions are almost identical. All that was really needed were new cables, and a set of bearings (2) from allballsracing.com. They are night and day better than the stock XJ forks.

 

Wich Year - Have found one from a 1992 GSXR1100, havent picked it up yet though.

 

I think it's from a 2005 750. It's new enough that it doesn't have a speed sensor in the front, but they stem dimensions hadn't changed yet.