Radian 600

Hey I'm looking at buying a new bike to run into the ground after putting 25k+ miles on my XJ550, and I've found a Radian close to me for a great price and it looks good too --- are they significantly different or will my wrenching experience transfer right over? Will I be kicked out of XJ bikes?

 

It's an XJ.

The Radian is a classic example of Yamaha's "parts room engineering" it's essentially a Maxim 550 frame with an FJ600 motor in it; a LOT of parts interchange with the 550s. All of the same challenges apply as well.

How many miles on your 550, total? 25K isn't a lot.

 

The Radian has 21k and my xj just rolled over 55k

 

Cool, makes sense now.

The Radian is basically a gutsier, "sportier" version of your 550 Max; if you like the styling you should love the bike. Your wrenching experience will definitely transfer right over (with a few new little quirks here and there of course.)

 

Well Fitz I bought it, the odometer doesn't work, so it has more miles than I thought, estimated by an obviously honest previous owner at 25k. Valves checked and carbs rebuilt, including jets and sync, 2-3k miles ago, done by a shop. My butt dyno says it pulls much harder than my 550, but the seat position is higher and it takes more input to lean the bike. It's also got a weird ugly headlight and stock mufflers which are way too quiet for my taste, but for $500 I can't complain

 

The stock headlight wasn't all that much prettier, unless you like the rectangular lamp look. See pic below.

If it were me, I'd figure out how to install a nice "normal" 7" round headlight from a 550 and make it look "factory" doing it.

Remember too, it's not much newer than your XJ; all of the usual concerns apply in regard to the brakes, chain and sprockets, etc.

Nice find though, especially since it runs. Valve adjustment interval is still 5K I do believe, so with a broken odo I wouldn't trust the 2K ~ 3K guesstimate, I'd look. It may use a different type of valve bucket hold-down tool, not sure. YICS is gone.

 

After a week of riding I'm ready to sell the Radian and keep the XJ 550 - there are weird rubber dampers built into the risers that make steering inputs slow...I guess it's to keep it easier to manage at low speeds but it's almost cost me my butt a few times....also the brake feel is exceptionally bad, rock hard wooden lever that's caused me to almost dump it twice now from unexpected lockups --- my 550 was bad with the stock master but not this terrible

 

Have you followed the recommendations above, especially re: brakes? I wouldn't be surprised at your review if the bike's hasn't been maintained.

A set of SS lines, organic pads and master cylinder rebuild alone should offer a very nice change and increase your enjoyment.

 

After doing research I'm 100% sure that the problem is Yamaha's choices at the time, dual 42.8mm brake pistons and a 15.87mm master cylinder is a recipe for disaster. I know not many around here change their hydraulic advantage ratio but I ride most of the time in the rain and wet pavement isn't nearly as forgiving of poor lever feel. I just can't decide whether go with an 11mm bore which is a fairly soft 30:1 but inexpensive vs a 12mm that will get me 25:1 and similar to what the 11m accomplished for me on my 550

 

I wouldn't assume a "design fault" until you've rebuilt the brakes.

You could be dealing with an internally ruptured/constricted line, or a balky caliper that is dragging enough to overheat a pad (or padS) which can cause lockups, big time. I would expect original 1986-vintage brakes to be spongy, the fact that you have a rock-hard lever tends to indicate that something's not quite right.

 

Are you talking about the rubber sleeves that surround the riser bolts? These were to reduce road harshness - many bikes had (have?) them. Easy to replace with new, or get aluminum bushings.

+10 on responses regarding brakes - there is an abnormal condition with yours that needs fixed.

For reference, check out this companion discussion: Radian Project

 

I took the time to sit the bikes side by side and work the brakes and see what the issue is, I rechecked the numbers and the stock master cylinder should give a smooth progressive feel -- what's happening is there is a notchy engagement of the master, and when I overcome that initial resistance it's causing me to apply the brakes too hard--I'm going to see how well I can manage it before getting a new master. I'll look for aluminum bushings, thanks for the tip!

I don't really have a choice anymore anyway, my XJ dropped a cylinder on my last ride and I haven't figured out the problem yet , valves were in spec at last check, well under 1k miles, new plug didn't fix it, and the carb has plenty of fuel in the bowl - compression check next I guess

 

I had something similar happen shortly after a carb disassembly. Make sure your piston slides on the problem cylinder pass the "clunk test", and do not hang up in any direction of travel.

Good luck and hopefully the compression test does not end up compressing the hell out of your wallet.

 

Stop fiddling with the Radian's brakes and rebuild them completely. New lines, rebuild calipers and master cylinder, new pads.

 

Ugh I am kicking myself now, my intake boot failed, cylinder warms right up with a shot of wd40, annoying expense on a bike I was planning to sell