Tips & Fixes


FJs are sturdy mounts, and put up with hard riding for many years without complaint. They sometimes do have their quirks tough, and this section is devoted to the common fixes for little annoyances that add so much character to the bike.

See too Choosing FJ Adjusting SAG  and Clutch hose change


I think is due to FJ 1200 is a simple over bored FJ 1100, because I don’t remember all those seismic vibrations in my 1100, that causes broken fairing tabs and screw drops in 1200 models until the 1991 on model, with special rubber in the chassis fittings.

Anyway, to minimize vibrations, here it is a little checking list:

1.- Check and repair the carb diaphragms. Below there is a method to repair these and avoid bankruptcy, because the Yamaha spares are very expensive.

2.- Its essential keeping the OE weighty bar ends.

3.- Dismount and grease the engine rubber mounts. Use red rubber grease. When refitting, apply the correct torque specified at the workshop manual, no more.

4.- Check the rim bearings.

5.- Fit the OE front sprocket. Its not so expensive and come with a vibration damper grommet inbuilt.

6.- Check the wheel alignment. The swing arm marks are useful. Do it taking measures from both sides of the swing arm.

7.- Of course, all of above is starting from a correct carb balance and valve clearances checked.



It seems that the regulator hot left engine position causes that it start overcharging and it causes the battery fluid boils and evaporate, leaving the battery dead. It is commented that Yamaha fitted the sealed battery to 91 on models to avoid this splashed fluid problem, because sealed batteries don’t contain fluid, and, obviously, it can't boil.

OE regulator is overly overpriced so try one from ELECTREX part nº RG25. Cheap and dead easy to fit with the instructions supplied. 7 years since fitted, the regulator works perfectly. and the service support is top notch: near 3 years after I bought the regulator, they answered my mail with a technical question NEXT DAY! TOP NOTCH! (Read it at the FJ medical centre section)

Update: Electrex don't make this regulator anymore. Buy the Nippon Denso, not a cheap Chinese one


 Fuel starvation 

In older models, it seems to be a problem with the venting of the gas cap not letting enough air in, and this builds up a vacuum in the tank, starving the carbs. The permanent fix for this involved disassembling the gas cap and removing these 2 little orange pieces of rubber that are supposed to act as some kind of vapour valve. See the fuel tank cap trick in the carburetion section 

On 1100 and 86-88 1200 models it is the time to repair the vacuum fuel petcock. See carbs section.


 Bouncing speedometer 

Dismount the dashboard and clean carefully the speedo inner semi spheres with WD 40 and contact cleaner. Look for any scratches on the surfaces in contact, if there is any, the gauge can be repaired.

Check that the speedo cable is correctly tightened and problem solved.

And I DON'T RECOMMEND painting the speedo & tacho needles with nail paint. You can't see anything at night. Tested. :-(


Sump plug screw and threads stripped 

It is definitely an ugly problem of the FJ models: when tightening the sum plug I have stripped 2 times the threads along the time. My 1st time was in 1992 in my FJ 1100 and now it is my 2nd time in my FJ 1200. And it is not due to over tightening.

Like a prevention, use always a new gasket.

Fixing is not difficult, only time consumer: you have to dismount exhausts and oil pan. Fortunately, It is not necessary to take the motor off the chassis, only the oil pan. Fit an helicoid and refit all again


Rear shock mudguard 

I bought a car mud flap with the Yamaha logo printed, drilled the bike guard with a 8 mm drill and attached with a couple of screws


Clutch bleeding    see too Clutch hose change

After a lot of hours bleeding my FJs clutches when I changed the hose, a car mechanic told me the best solution, the same that in Peugeot 504 models: simply, refill the circuit, close the nipple of the push-rod, left the master cylinder deposit open and push the lever one hundred times (or similar, UFF!). You will see the air pumps going out the circuit. After a quarter of an hour, more or less, you will get your circuit free of air.


Exhaust refitting

When refitting exhausts, if you re-use the gaskets , apply a special-exhaust paste that you can buy in any auto-store. Fit the exhaust, ride around the bike to let the exhaust get hot and retighten the screws with the exhaust at working temperature. And be careful do not to touch any part of the exhausts directly with your skin!!!!.


Head bearings 

Replace of the head bearings is my worst nightmare in the FJs. I changed them 10 years ago in my FJ 1100 and again in my new FJ last June. It is near impossible to follow the workshop manual procedure: punch the inner bearing races with a screwdriver and a hammer: there is no area to base the screwdriver to push the down bearing race.

In my 1100, I got take out the down head race welding a piece of iron to have area to punch it out, and in my 1200 with a little radial-saw, mm to mm grinding for 10 hours the race surface until it collapse, being horrified for the possibility of damage the chassis inner head

There is other method in my mechanical consultory section.

IMPORTANT NOTE: the grommet with the nº 5 at the part catalogue in the picture at the left is necessary in order to get the proper bearing torque. If discarded, when the torque is applied at the head nut (nº 7) the bearings get too much tightened.

Trick to torque properly the head bearings: this step is fundamental to get a correct handling in our FJs. You must torque the castellated nut to 5,5 kmg, release it and tighten to 0,3 kgm.

It is possible to make the correct adjustment without the light dynamometer tool: simply wear a summer glove and tighten the single castellated nut on hand, not with the seond on it.

It is very important tighten the stem nut to the correct 11 kgm specified.

IMPORTANT: the little nº5 grommet at the pic. If it is not in its place or put a shim, the stem will be to much tightened. Yes, looks incredible, but it has been tested.

FJ 1100 front collector's double wall

FJ 1100s fit a double wall headers that suffer from inner cracks and those sound like piston/conrods failure. You can live with the noise and it doesn't affect the motor health. This problem was solvent by Yamaha fitting a single wall headers in the FJ 1200 models, and by me in my first FJ 1100 buying a Muzzy exhaust.


Don't fit economy transmission kits. Any chain with less quality than top of the range (and expensive) DID ZXVM chain is money throw to the bin. I clean the chain each 1.000 km. with WD40, grease it (with a Teflon free product to avoid road grim pasted and actuating like grind paste) and clean the excess with linen. I obtain around 100.000 kms. from my chains.

Fork oil

You can change the fork oil without dismantle the fork legs from the bike, thanks to the plug screw at the bottom of each fork vase. But if you use this way, you will only get about 300 cc of fork oil, instead of the 395 cc to 425 cc that there is inside of each leg. Particularly, I prefer dismantle the legs to be sure I have plugged all the old oil, and adjust levels and quantities with completely new oil.

Carb Diaphragm repair

My carbs had 2 carb slides diaphragms with various little holes. The consequences are poor fuel consumption and vibration. The OE spares are very expensive (about 200 €), even although at the FJOCUK are cheaper because they are exchange basis: you send your slides and they fit the diaphragms.

Anyway, you can use Plasti-Dip. The 1st problem was found it: in Tenerife nobody know what I was speaking about, and I visited A LOT of hardware and auto store shops. So I had to order to Britain: the post was more expensive than the Plasti-Dip, so I ordered a pair of bottles. Total cost: 40 € from . Buy it at FROST

Well, It is FANTASTIC!. I mixed it with 20% naphtha and painted the diaphragm holes with a pencil, allowing to dry overnight. Ready!. It is near the OE flexibility and they look more resistant than before. Job done. I've checked a couple of times in 12 years and the fixing are permanent


Carb manifolds fitting

The carb to airbox manifolds get hardened with the engine hot & by years, so it could be near impossible to fit them properly. It is even more difficult in my CBX than in my FJ because there are not heat windshield protecting the carbs and consequently the parts are even more hard to bend and manipulate to refit them. The trick can be used with any other grommet part on the bike to soften it

The solution is easy: buy new parts, but expensive. So boil the parts 5 min in water 5 min and then immerse the parts in liquid Vaseline for 12 hours. The parts recover most of their flexibility and you need less effort to refit these. IMPORTANT NOTE: it is recommended only for single or leaving alone people. Don't do it with your couple/mother/wife at home because the refitting process could be peanuts compared with the consequences of using her cook ;-)

Valve clearances & Ford valve shims

Valve clearances on race bikes are settled on minimum clearance the intake valves and maximun on exhaust valves, between specs, so the combustion chamber get a optimum emptied in each complete piston stroke. In our FJ the adjustment used on race bikes are 0.11-0.12 intake and 0.20-0.21 exhaust.

Getting these precise adjustment in our FJs is very complicated because the Yamaha shims are made with a 0.05 gap between sizes. Well, the solution reside on fitting 25 mm. Ford valve shims, with a gap of only 0.025 between sizes. On the pic there is a table with valve sizes and Ford part numbers. As far as I know, the parts numbers are for European Ford models, ZETEC 1.4 engines.

At the left are the shim sizes with UK & Spain part numbers.


Headlamp adjuster repaired

Dead easy and cheap, the trick come from a Spanish FJowner, member of our FJ whatsupp Spanish community

Buy an RC radio control car trasmission cardan from Aliexpress. The perfect sizes are 5x6, but 6x6 do the task too. Fit it to the remote dipstick and to the headlamp. Ready. With the allen screws provided to fix the cardan you could dismount it if you like.

Clever and simple!

Extended side stand security switch

FJ 1100 / FJ 1200 1TX 1986-1987

All of us know the function of this security system, that avoid the ride of the bike with the side stand extended, with the consequent risk of turning left and going straight when the left out side stand touch the ground.

The system has 2 functions: first, with the engine running, stop the engine if the side stand is extended and any gear is engaged, and second, avoid starting the engine pushing the clutch with a gear engaged and the side stand extended. The electric esquem describe these functions.

Interestingly, on European limited 100 hp or less 1986-1987 FJ 1200s (France, Germany, Switzerland ...) or USA models this device comes factory fitted, while on the free power European markets, code 1TX , Spain, Italy, United Kingdom ... it is not present.

As far as I know, no 1100s fit it from factory, so all of these benefit from this mod.

Parts needed: FJ 1200 88-90, 3CV, 3CW or 1XJ 1986-87 (from France or Germany) left chassis rail, (with switch base), side stand  (protruded toactivate the switch) , and switch itself.

Good painted and fitted, the parts look original equipment.

On FJ 1100s is mandatory to change the right chassis rail too, to fit a 1200 front chin, or fix and weld a front support for the original 1100 chin, different of those fitted on 1200s.

We are in debt with my friend Mingo for this ESSENTIAL MOD who has studied the 1200 electrical diagram with the wires of another parted 1200 that we own


- We remove the electrical installation from the left side and look for the 2 sets of taped wires, as they come from factory. (Pic 1).

- Peel the tape and we find 3 wires welded (Pic 2) .

- One of them go to the start engine and other to coils. The wire that go to the starter must be cut. Cut one of the two and press lightly the start. If it engage, you are wrong and it is the other wire  (¡Ouch!). If not, you are right. (Pic 3). In our bikes, this wire cut is red/white, if it helps.

- Weld a new wire to the starter wire that we have identified previously, that will go later connected to relay port 87 (Pic 4).

- Re-weld the original 3 wire connection, this time with a new wire that will be later connected to relay ports 85 and 30, both ports serial connected between them, so the voltage go thought the main fuse and when connected, give power to the RUN circuit and the complete installation. It is clearly observable in Pic 5

- Everything is wrapped again and put back in her place (Pic 6)

- Now we go to the other side of the bike: install the side stand switch (Pic 7) and guide the wire until it appears near the neutral green connector that we will later manipulate (Pic 8), hence the new connectors will look perfectly integrated with the original installation connectors of the area. The red wires in Pic 8 that you see on the left is the ones that we welded on the other side and we have guided to this left side to connect them to the relay as is described previously.


- Built a new wire with a diode integrated in it. It is connected to the chassis to get ground. (Pics  9 & 10). This wire is the first connection on the 2 male main connector where the side stand switch female will be connected later.

- The second wire on the male connector will go to relay port 86, joined or welded with a wire that comes from the blue neutral wire (Pic 12), this wire fitted as described in the following step.

- Prepare this second wire from the Neutral wire, the blue one on the green connector. Insert a diode on it and weld it or join with the wire of the previous step. Both of them go to the relay port 86 (Pics 11 & 12)

- Connect everything as it is described at the relay: the red wire from the starter wire to the relay port 87, the red wire from the installation to the relay ports 85 & 37, and the neutral and side stand wires to relay port 86 and  situate the relay in a cavity situated at the front left of the battery case. It looks like it was specially designed for it, because it fits perfectly. (Pics 14 & 15)

Ready!. I've tried that everything is clear, easy  and well explained. But the electrical part of the mechanics is not my strong, and even after having installed with Mingo, I have being consulting again. Combine it with that English is not my mother language, so please be patient, read carefully and study the task before to proceed to perform it.

We have installed this mod for our security, and have made the effort to document here because we think it is an ESSENTIAL MOD to install in all the FJ types that don't bring it from factory.

Cush-drive change

Click to see on the video the cush drive slack in my FJ 3CV with Suzuki GSXR 5,5 rim .

Time to change it. I've bought an aftermarket replacement in USA. Fantastic material!. It fits so tight that you need another couple of hands to help you to install the grommets in the rim. While one is pushing and maintaining pressure on the sprocket carrier, the other situate the sprocket carrier tabs one by one with a screw driver in their places. After all of them are in their correct places, make pressure and ready RECOMENDED

Errors in manuals and engine rebuilt tips


To install the distribution chain tensioner, the right position is the reverse of what is specified in the Clymer manual.



The cupper shims go to the right side of the head, not the left, as stated in Haynes and Yamaha original workshop manuals

The part where the inner damper fit previous to screw to the fork bottle goes with the flat top at the bottom, upside down to that shown at Clymer mannual.



IMPORTANT: re-torque the head after first 1.000 km. with engine at working temperature

RIVETING THE DISTRIBUTION CHAIN: it is possible to replace the timing chain without splitting the crankcases. Buy the proper chain and a clip to rivet it, and, with the help of a friend, with a cobbler's hammer, go rivetting tapping it carefully.. No, no other hammer type. The circular shape fits the rivet perfectly and leaves it perfect.

This bike has done 40.000 km from when the repair was performed, so it is tested that works.