Notes from my YZF600 Rear Wheel Install

[SlowOldGuy]

After what seems like several years of jacking with it, a YZF600 rear wheel is finally installed on my '85FJ.  Here are a few observations about the installation.

When I got the stock wheel off, the shock linkages were really dirty so I decided to do a bit of cleaning.  The linkage connecting the swingarm and shock was easy enough to get off and cleaned up nicely.  Bushings were in good shape.  Removing the link that connects to the frame turned out to be a major pain requiring disassembly of about half the bike.  I had to remove the chin fairing and the entire exhaust system; mufflers, collector, and headers).  

That wasn't so bad as the collector box needed a few coats of high temp black paint and the headers got some polishing.  Even after dropping the exhaust, I still couldn't get the pivot bolt out; it was hitting the right side foot peg backing plate assembly.  Removal of this assembly required removing about 20 bolts/nuts including the swingarm pivot nut, motor mount nut, lower frame rail bolts, foot peg bolts, rear brake master cylinder mounting bolts, and the crash bar bolt.

It would have been much easier if the factory had cut a small 1/2" radius half moon out of the bottom edge of the backing plate so the bolt would clear.  Eventually I got all the linkages cleaned, regreased, and reinstalled.  Finally back to installing the wheel.  

Thanks to Arnie for posting the trick about freezing the bearings.  This, along with heating the wheel hub, made bearing installation a real breeze.

All the machine work was good, the wheel fit nicely and the sprocket was lined up.  To my surprise, the brake torque arm didn't need any modification or bending to clear the tire.  Also, the stock FJ rear caliper fits fine so I can continue to deplete my stockpile of FA-88 rear brake pads.  

On the bad side, the rear brake line needs about 1/2 inch to fit better; it's stretched to the limit.  After searching locally for someone to make up a custom line, I finally ordered a longer brake line from Spiegler.  For some reason that I haven't figured out yet, the brake pads are dragging on the disc.  Must be that DOT 5 fluid.  :-)

When installing the tire, I didn't get the bead to seat uniformly around the tire which caused a slight out-of-roundness that required more balancing weight than necessary and produced a bad vibration at speed.  I had to remove the wheel, break the bead and reseat it several times to get a uniform sidewall.  I was then able to pull off half of the 1.5 ounce of balance weights.  A high speed test ride showed the vibration was now gone.

Impressions from the initial test ride are positive, now that the vibration is gone.  It's not the amazing transformation that the 17 inch front wheel mods is, but it does seem to rail through the corners with less effort.  The Pilot Road 2CT seems like a good tire.  I'll match up the front in a few miles once the D205 expires.

I'm sad to see the Harley tire finally retired, it's still got a few miles left.  I'll hang onto it as a last ditch spare wheel/tire assembly.  

One final surprise was that I didn't have to increase the ride height significantly.  I chose the 160/60 tire size, and it only required about 1 and 1/2 turns on the lower shock mount to put the tire on the floor on the centerstand.  

It's a good mod and maybe it's just the order that I did the modifications in, but I'd still say the front wheel upgrade is more significant for an early model FJ.

DavidR.

Oh yeah, one final thing.  No ignition problems over the same route that had them last week.  I'm almost sure the problem has magically healed itself.  :-(

[Fudge]

Be careful if you used the stock FJ rear caliper, it's wider than the stock YZF rear caliper because it has to accomodate the width of the vented rotor.  When the rear pads get thin from wear they could potentially slide out of the stock caliper.

[SlowOldGuy]

Do you mean the PISTONS could pop out?  With the pins, there's no way the PADS are goiing to fall out.

DavidR.

[andyb]

There was concern that the pads could shift enough to lock in an on position, I believe from mister Cain.  Also he absolutely suggested modifying the brake torque arm.  Neither's been a problem for me, but there you go.

[jvb_ca]

Great report David. Your reviews are always well written and very concise.   

Also, the stock FJ rear caliper fits fine so I can continue to deplete my stockpile of FA-88 rear brake pads.  

On the bad side, the rear brake line needs about 1/2 inch to fit better; it's stretched to the limit.  After searching locally for someone to make up a custom line, I finally ordered a longer brake line from Spiegler.  For some reason that I haven't figured out yet, the brake pads are dragging on the disc.  Must be that DOT 5 fluid.

The dragging brake is probably from the caliper being a tad too wide. The pistons are poking out further than they had before and are not letting off as they should. I am currently dealing with the same issue with one of my front calipers. Once I switched to ebc hh pads from oem pads I have this prob. Have cleaned the pistons twice but they are still dragging a bit.

When installing the tire, I didn't get the bead to seat uniformly around the tire which caused a slight out-of-roundness that required more balancing weight than necessary and produced a bad vibration at speed.  I had to remove the wheel, break the bead and reseat it several times to get a uniform sidewall.  I was then able to pull off half of the 1.5 ounce of balance weights.  A high speed test ride showed the vibration was now gone.

I also had the same problem with my first set of pr's. After numerous tries mounting and dismounting I finally got Michelin to spring for a new tire. About that time they were having some manufacturing issues and recalls on the new at the time pr2's. I thought that there was a problem with my wheel, but the new tire fit and balanced perfectly first try. Last year when I replaced these pr's with new pr2's I had the same issue with the front tire. Three times remounted and balanced. Is drivable now but still not perfect. I am not convinced on the build quality of these tires. Have heard nothing but positives about them, but my experience has not been very favorable. On a good note, they ride quality is very good and mileage is decent. They warm up quick and stick better than the old bias ply ever did and give a very solid confident feel.
I look forward to your long term review....

Cheers...Jake

[SlowOldGuy]

Well, this is interesting.  It appears that the YZF rear brake caliper takes the same pads as the FJ rear caliper.  I didn't know that.  Looks like I'll go ahead and swap over to the YZF caliper and see if that cures my dragging brake.

I even have a caliper rebuild kit for the FJ that will work on the YZ.

Finally found a local shop that will build me a custom brake line for half of what the "motorcycle brake line suppliers" want. 

DavidR.

[SlowOldGuy]

Okay, I may be the only one reading this, but it's nice to have the information out there.

Fixed my dragging rear brake.  New pads were the answer.  The old ones were worn at an angle which was causing them to bind up and drag.

Here's some more notes on the brake.  The rear YZF caliper is identical to the FJ rear caliper, except it's slightly narrower since it doesn't use the ventilated rotor (thanks to Fudge for posting this fact).  I split the YZF caliper and cleaned it all up.  I then removed my FJ caliper and split it also.  The pistons are the same size, so my caliper seal kit works on the YZF caliper.

However, I didn't like the outside half of the YZF caliper; the paint was messed up and it didn't say YAMAHA like my FJ caliper does.  Therefore, I used the pieces to build my own caliper.  I used the inside half of the YZF and the outside half of the FJ caliper.  New pads and a new custom braided SS line ($30) and all is well in the brake department.

DavidR.

[Mark Olson]

Okay, I may be the only one reading this, but it's nice to have the information out there.

Fixed my dragging rear brake.  New pads were the answer.  The old ones were worn at an angle which was causing them to bind up and drag.

Here's some more notes on the brake.  The rear YZF caliper is identical to the FJ rear caliper, except it's slightly narrower since it doesn't use the ventilated rotor (thanks to Fudge for posting this fact).  I split the YZF caliper and cleaned it all up.  I then removed my FJ caliper and split it also.  The pistons are the same size, so my caliper seal kit works on the YZF caliper.

However, I didn't like the outside half of the YZF caliper; the paint was messed up and it didn't say YAMAHA like my FJ caliper does.  Therefore, I used the pieces to build my own caliper.  I used the inside half of the YZF and the outside half of the FJ caliper.  New pads and a new custom braided SS line ($30) and all is well in the brake department.

DavidR.

you are not the only one reading this post.

others are paying attention.

[rktmanfj]

you are not the only one reading this post.

others are paying attention.

+1

FWIW, I am still using the stock FJ rear caliper.

Ran the rear pads down to paper thin (wasn't paying attention-the YZF rotor seems to consume pad material quicker than the stocker) with no problems.

Replaced those with EBC HH last fall.

Randy T
Indy