Modifications for your FJ

[andyb]

This is going to be a long, long post.  Expect it to take ages to make remotely complete!  I'll reply to this post for small things, and start or link to other threads for more complex subjects... it's getting there... slowly..  
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If you don't see what you want here, there's an entire subforum for asking, an entire function for searching, and other places to look for information as well.  Just trying to tie it all together here to speed the process!

Where I include links to various suppliers for parts, be aware that there are likely others also, I'm just giving the ones that I'm familiar with or that someone points out to me.
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Engine modifications include, in rough order of difficulty and power available
    -Spin-on oil filter mount - No power gain, but it's handy - see RPM
    -Oil Cooler Upgrades - Helps handle upgraded motors live.  Randy's got a great kit available now.
    -Heavy-duty Studs mixed feelings from engine builders
    -Heavy-duty nuts (expect some seepage out the tops if you don't use a sealant; late OEM work (PN# 90176-10070-00))
    -Heavy-duty valve springs - Required with big cams or nitrous, helps prevent spitting shims and valve float.  APE and Kibblewhite supply them (ask Randy!)
    -High-flow petcock - more
    -Starters for modded motors.
    -Air filter
    -Airbox modification
    -Airbox removal (pod filters)
    -Slipon exhaust - Lots of options if you're comfortable with a little fabrication.
    -Full exhausts - Rejetting required.  V&H, D&D, Kerker, Laser, SuperTrapp among others are out there.  Most are out of production now, but you can find NOS or used.  XJ1200/1300 exhausts also fit.
    -Sidewinder exhausts - Very hard to find!  V&H, Murray, and others used to make them.  A GS1150 pipe fits with some "adjustment"
    -Spark advancer, or ignition advancer (same thing, different name included for people using search function)
    -Relay for coils
    -Aftermarket coils
    -Thinner base gasket - Measure your piston to head clearance, .040" is safe, .035" is really pushing it a bit (OEM base gasket is .020", head gasket is 0.030".) Cometic is one source.
    -Shaved/skimmed head - Usually done to true the head, the valve seats sit low enough that there's not much to gain.  This alters compression without changing quench/squish.  Get appropriate pistons instead (elsewhere in this list).
    -Degreed camshafts (slotted cam gears), then degree them in (read whole thread first).
    -Aftermarket camshafts Web Cams
    -OEM pistons (FJ1200 pistons in a FJ1100, 1188cc 9.7:1, PN 1TX-11631-00-A0, oversized are available)
    -Aftermarket pistons (Wiseco are most popular, but Ross, JE, and Mahle are out there, among others)
    -XJR1300 (1250cc, 79mm) blocks are siamesed and nikasil plated from the factory
    -XJR1300 blocks have been able to use a 83mm piston from Wossner, but it doesn't appear to be available anymore.
    -Aftermarket cylinder blocks -up to 90mm bore, hard to find..yeah, 1623cc... (not really streetable)
    -Crankshaft lightening
    -Aftermarket rods.  In order of increasing strength:  stock, XJR, Carillo A-beam, Carillio H-beam, Crower H-beam. Wossner may or may not be available.  Weights.
    -Power Adders
          -Nitrous -Kits are available, but you're on your own. It will have to be a wet shot; dry shots are for FI only.
          -Turbocharging -MrTurbo had a kit, not listed anymore, but they'd probably make one for you
          -Supercharging -You're on your own
          -Alcohol -You're on your own
          -Nitromethane (Fuel) -You're on your own AND you're a nutjob, but 1000hp is doable...
    -Induction/carburation
           -Jet kits - FactoryPro (1100 1200), DynoJet
           -All rejetting help starts here for CV (non-flatside) carbs
           -Larger Mikuni carbs (RS38's for example)
           -FCR carbs
           -Lectrons Drag use only
           -Fuel Injection -You're on your own, but MegaSquirt or adapting another bike's setup (XJR1300 2007+) would be the place to start.

Or have a pro do your motor work for you.  RPM and HSR, among others.

Clutch, in rough order... (all clutch questions should start here though!)
    -Single FJR spring (pn# 5JW-16334-00-00, fits as a stock replacement)
    -Aftermarket single spring May not be a good option, read the post.
    -Doubled OEM springs
    -Coil spring conversion
    -Uprated Coil Springs
    -Billet steel basket Not necessary unless 200hp and/or using a lockup clutch.
    -Aftermarket friction plates (not recommended, use OEM)
    -Swap to more wide fibers, replacing the narrow pair
    -Single stage lockup clutches -Not available new anymore (MRE made them), drag race and +180hp only
    -Slider clutches -You're on your own, haven't seen one for the FJ yet... see next entry!
    -Replace entire clutch with another bike's setup (GSX1300R or KZ1000 for example)
    -Clutch cushion -BDE's design was never adapted for the FJ, but a machinist could make one (if you're capable, let me know and I can give you as much of the measurements that I've found to work with)
     -Slipper Clutch - Sigma makes these, interchange FJ/XJR all years
     -Braided steel clutch line - Get one made, or buy from Bremzen, Galfer (PN FK003D89CL), ABB, or others.

Transmission
    -Shift kit -  RPM Roller Shift Detent Kit
    -Undercut gears (prevention of the second gear problem, also can happen in first under high loads), FBG or R&D are good
    -Late shift forks are longer than early ones and a bit stronger, helps prevent second gear issues.  Randy has them, compare the markings to yours to see which you have.

Front suspension mods, again in a rough order of complexity, cost, effectiveness
    -88+ fork lowers on the earlier models, XJR lowers should fit also
    -Different fork oil
    -Renntec crash bars
    -Fork braces (SuperBrace is most common but discontinued).  RPM has them now.
    -Cartridge emulators
    -RPM fork valves
    -Preload spacers -Link shows similar fork type
    -Aftermarket fork springs - Progressive and Race Tech make them, call and find out what's best for your size/riding situation
    -Yamaha family front end swaps, i.e., FZR1000 87-88 wheel or YZF750 or FZR1000 USD or early R1
    -Other front end swaps (anything fits if you've got the time and money)
    -Aftermarket forks (speaking of money)

Rear suspension mods
    -Replacement dogbones (88+ only)
    -Widened stock wheels
    -YZF600R (17x5.0) swap
    -GSXR1100 (17x4.5) swap
    -GSXR750/1100 (17x4.5 or 17x5.5) More Instructions!
    -FZR1000 (17x5.5) swap, more
    -YZF1000R (17x5.5) swap -Swingarm included
    -YZF750R swingarm is dead sexy
    -R1 -Swingarm included
    -FZ swap No speedo drive.
    -Aftermarket shocks (Hagon, Penske, Ohlins, etc.)

Braking
    -Aftermarket pads (use sintered, OEM rotors are steel
    -Aftermarket rotors ebay, Galfer, EBC, possibly others
    -Braided steel lines (10mmx1.25, more
    -ABS removal
    -Anti-dive removal (more on them)
    -Monobloc calipers 98-03 R1, others may fit, look for the blue dots, though some are other colors.  This is for the 88+ FJ forks only. Interestingly these were stock on later XJRs.
    -FZR400 calipers will fit the 84-87 fork legs, but are a bit hard to find used.  The bolt spacing is 83mm, so measure before you buy.
    -Aftermarket calipers - Brembo, others

Lighting
    -Replacement bulbs
    -Headlight relay
    -HID kits
    -Additional lighting

Luggage
     -Givi and similar
     -Others

Seating/comfort
     -Seat pads
     -Recovering/shaping stock seats
     -Corbin Gunfighter/Gunfighter and Lady
     -Sargent
     -Bar Ends (less vibration)
     -Handlebar risers
          -Helibars (not available new anymore)
          -Genmar risers (or make your own)
     -Clipon to handlebar conversions (LSL for example)
     -Master cylinder swaps 14mm brake master, radial master, OEM is 5/8, works on clutch side also.
    -CBR mirrors work on some years with modification.
    -Other mirrors
    -Anti-Vibe bar ends - Other options available also

[andyb]

Air filters for the stock airbox:

OEM - What the bike came with.  It'll work.
Emgo, other paper OEM replacements - They'll work, cheaper than OEM.  Don't expect a power increase.
K&N - A gauze element wrapped with screen, using an oil to make it a pretty color and attract dirt.  Part number: YA-1184
UNI - An open cell foam filter that is saturated with a sticky oil.  Doesn't look as nice as the K&N, filtration and power will be comparable.  Part number is NU2280.


According to DynoJet, drilling about 20 1/2" holes in the sides of the airbox will allow you to run "bigger" jetting, and in theory make increased power.

A mod that I've not heard of anyone doing yet is creating velocity stacks for within the airbox.  Have seen stacks on open carbs, but race use only!  Any dirt can quickly destroy valve sealing ability.  Adjusting the stack length changes power characteristics, longer = lower revs, shorter = higher revs.

If you decide to remove the airbox, you can gain a bit of top end power and use individual (pod) filters.  You will likely lose some of the smoothness of the power delivery, and have to rejet to get things running well.  It does make it easier to work on the carbs because you won't have to fight the airbox, though.  When you remove the airbox and install pods, you will also need to come up with a filter for the crankcase breather hose.

Pod filter options include:

Cheap Emgo or similar pod filters - If you're going to bother, spend the money for the UNI's.  Well worth the difference.
K&N individual filters - Make good power, but the kit as supplied by K&N fits quite badly.  Turning the outside pair of filters upside down and at a slight angle will help, as will using a 1/2" wide hose clamp instead of the clamps supplied.  They're also rather expensive.  Part number: RC2814
UNI individual filters - These can be had with chrome end caps (pn# PK92), or you can buy them to fit from the UNI universal fit catalog.
UNI dual filters - These are a dual-stage foam, and are generally accepted as one of the best possible options.  PN is DP3229.

[andyb]

Aftermarket Coils

The benefit here in theory is that you will have more spark energy at the plug gap, creating a hotter fire, longer burn, and get more power from your motor.  You may also gain easier starting, and it may help burn lower quality gasoline (read:  not lower octane, but physically worse gas, watered/additives/old/blown-down/etc).  Another perk is that the wires are then very easily changed out, rather than the screwed in wires on the OEM setup.

The FJ coils are little black things with the coil leads (connect to the sparkplugs at the other end).  They're mounted under the tank near the headstock, and are easily found once you pull the tank off.  The FJ uses a wasted spark system, meaning that the coils fire "needlessly" half the time.  Cylinders 1+4 are serviced by one coil, and 2+3 by the other.  When the piston is nearly to the top of the stroke, the coil fires both cylinders, regardless of where the cams are--meaning, it fires on the exhaust stroke half the time.  It's been argued that this helps to clean the plugs, but it mostly means that you only need two coils rather than four, and wiring is much simpler.

The options for an FJ as I know them are:

-Accel coils.  PN 140403.  These are significantly larger than stock physically, and will require some work to make them fit.  Remember that they need to be solidly mounted with a good ground signal.

-DynaTek (Dyna) coils.  PN varies.  These are a popular replacement, and use the stock mounts without issue.

-Another option is coils from another machine, though I haven't heard of this being done on an FJ.  You'll need to match the resistance of the coil you want to use and compare it to the factory spec.  Further, you'll need something with dual outputs on each coils.  Lastly, you'd want something that fits the space you've got!  Helpful if they're heat and vibration resistant as well, seeing as they're mounted above an aircooled motor.

[andyb]

Ignition Advancers

These are getting nearly impossible to find new.  Vance and Hines was the main producer of these things, though Factory Pro may have made them for awhile.  You can also take the OEM spark trigger (located on the left side of the motor at the end of the crankshaft under a cover held on by four phillips screws) and enlarge the slot to allow adjustment.  FactoryPro (PN# RTR-YAM-6 for 88+) still has them available, but they're rather proud of them ($$$!).

Typically these are +4 or +5 degrees of advance.  The theory is that you light the spark off sooner (farther before TDC) and this causes the cylinder pressure to rise earlier, giving the mixture more time to push the piston down.  This is said to give better throttle response and a few hp worth of gains, particularly in the midrange.  The downside is that the engine will become more sensitive to low octane and have a chance to ping (detonate, preignite) more easily.  They're a safe bet for most street riders though, and can be found used relatively easily.

(I'm giving no instructions for slotting your own, on purpose.  If you're not dead certain of what you're doing, don't do it.  That being said, a quick search could give you a few useful posts on the subject.)

Later addition:  Someone did a pretty reasonable job at showing how to slot your own!  Fancypants!

[Scooterbob]

Ignition Advancers

These are getting nearly impossible to find new.  Vance and Hines was the main producer of these things, though Factory Pro may have made them for awhile. 

Just browsing real quick for this topic and found some here ---> http://www.cyclewareables.com/pages/street_ignition_advancer/ignitionadvance.htm

I spoke with a gentlemen there just a second ago and he has verified that these are new units.   

[Scooterbob]

I'm not bashing anyone, but why is this topic under the "Troubleshooting" header, instead of a sticky or something in the "Modifications" area?    Just think it would easier to find, rather than going through "Running Problems ->Troubleshooting/FAQ".  I may be wrong......if so, flame away. 

[weymouth399]

I bought one for my 91 they are out there, but hard to find. You can also slot the stator plate like some on has already said. This is what we do for the race cars. easy and cheaper
Bob

[andyb]

I'm not bashing anyone, but why is this topic under the "Troubleshooting" header, instead of a sticky or something in the "Modifications" area?    Just think it would easier to find, rather than going through "Running Problems ->Troubleshooting/FAQ".  I may be wrong......if so, flame away. 

It'll be moved or the subforum renamed or something, eventually.  No fear! 

Besides, the first question people have is "how do i fix <xxx>" and the second one is "well I fixed <xxxx> and now I want it to be more yet!" so it's semi-logical

[Scooterbob]

It'll be moved or the subforum renamed or something, eventually.  No fear! 

Besides, the first question people have is "how do i fix <xxx>" and the second one is "well I fixed <xxxx> and now I want it to be more yet!" so it's semi-logical

Good enough.  Didn't expect you to not defend your position anyway. 

[andyb]

From the yahoo list from John Hendry:


The trick to identifying the 83mm
Sumitomos versus the 100mm ones is that the 83mm use a single allen bolt
retaining pin through an eye in the top centre of the pad. The 100mm
Sumitomo calipers are a bit bigger and proportionally look very similar,
however they have two pins either end of the pad as a retaining mechanism.
Also the smaller of the two pistons is bigger on the 100mm.

The FZR400 (3TJ) is the 83mm brake caliper being described.