Grips changed; handlebar painted; additional fuel filter fitted.

Current odometer reading: 46339 miles.

An additional fuel filter (disposable type) was fitted between the fuel petcock and the original fuel filter, as a precautionary measure against particles in fuel (note that the carburettors were cleaned recently).

The worn out original handlebar grips were slipping and crumbling away. It was decided to replace these with new rubber Honda-style handlebar grips. While the handlebar was removed from the bike, the mirror mount positions were changed (moved inward in accordance with personal preference and for symmetry) and the handlebar and bar end weights were prepared and then painted matt black.

New front indicators fitted

Odometer reading: 46257 miles

Bike-It “Spear” type new front indicators fitted, as the bulb in the original front left indicator had failed, and during the bulb replacement, it was found that the bulb mounting was seriously corroded inside, and was making a poor/intermittent contact with the new bulb.

Old indicators were not retained, as their attachments bolts had seized, and one of them was faulty (as described). New indicators are a bulb type, 12V 23W, and it was not necessary to install any resistors in series or a new relay. All tested and working well.

new front indicators.jpg

Oil drained and replaced; oil filter replaced; exhaust leaks observed and repaired

Odometer reading at time of oil change: 45221 miles.

The following describes work carried out over a period of the last 3 days, during which the bike wasn’t ridden at all. This work was completed today 10/06/2017.

It was decided to replace all the oil and the oil filter. However, it was discovered that the sump plug drain bolt was seized, moreover that it was at an angle and could not be accessed with an ordinary ring spanner via the underside of the bike while the exhaust was fitted.

The exhaust was removed, and attempts were made to remove the sump plug drain bolt. However, it was too seized to move. It was decided to drain the oil via the oil level sensor, which is attached to the underside of the oil sump pan, and then to siphon off the remaining oil in the recesses of the oil sump pan using a hand pump. This operation was successful.

While the exhaust was removed, it was cleaned using Coke and wire wool. During this operation, several holes caused by corrosion were discovered in the exhaust. These were located at the joining pipe and in the silencer. The joining pipe was repaired using metal epoxy (not exhaust putty), offcuts of tin metal, and jubilee clamps. The silencer holes were bored wider to accommodate M6 screws, and screws were set in these using metal epoxy as a means of permanently plugging the leaks.

After draining the oil and refitting the oil level sensor and the exhaust, the oil was replaced in its entirety with Shell Advance 4T mineral oil, 15W40. A new oil filter (HiFlo Filtro brand) was fitted. The engine was started and the exhaust system repairs were found to be successful (i.e. there is no blowing around the repairs).


Valve clearances shimmed

Current odometer reading: 45051 miles

3 shims were replaced with new ones that had been procured as per previous post, and one was swapped with an existing one from a different valve, as described in the last post.

All valve clearances are now within spec, and will be inspected again within the next 3000 miles.

Surplus shims now held:

2 x 280

1 x 265

old shims.png

Valve shim removal tool procured. New measurements taken. Additional shims ordered.

Current odometer reading: 44844 miles (no additional miles travelled since last work)
Valve shim tool arrived, and allowed removal of valve shims and size readings.

Valve shim tool.png

More accurate valve clearance measurements (current) were taken, along with the shim sizes of shims to be replaced. Information as follows (shim readings are in brackets):

Inlet 1:            0.1     (280)

Exhaust 1:     0.17   (260)

Inlet 2:            0.09   (280)

Exhaust 2:     0.23

Inlet 3:            0.16

Exhaust 3:     0.2

Inlet 4:            0.11

Exhaust 4:     0.17   (265)

The following replacement shims are to be procured:

275 (for inlet 1)

255 (for exhaust 1)

275 (for inlet 2)

For exhaust 4, the 260-sized shim from exhaust 1 shall be substituted.

Front brake rebuilt with new pads and seals and fresh brake fluid. Diversion decals removed. New mirrors fitted.

Current odometer reading: 44844 miles.

Front brake rebuilt with new pads and seals. The old pads have been retained and put into storage as spares, as they are in good condition with lots of wear remaining. All front brake fluid bled and replaced.

Larger mirrors fitted (road-riding oriented, with better visibility).
new mirrors fitted.png

All standard Yamaha Diversion decals removed (personal preference).

decals removed.png

Carburettor cleaning and valve clearances check

It was necessary to check valve clearances, and this can only be done by removing the carburettors first. As the carburettors were off the bike, the opportunity was taken to carry out some basic tasks on all 4 of them, although not a complete disassembly:

  1. Clean float bowls.
  2. Clean all jets.
  3. Inspect diaphragms.
  4. Polish main jet needles.
  5. Reassemble carbs.
  6. Reset pilot mixture screws 2 turns out, as exactly as possible.
  7. Bench sync as exactly as possible.

The product used was STP Carburettor Cleaner Spray. The jets were removed and left to soak in a jar full of this cleaning solution, and were then blasted through with the spray nozzle. The jet holders were also blasted with carb cleaner. Float bowls were also cleaned and rust particles removed from them. The jet needles were polished using carb cleaner and aluminium foil.


The rocker cover was removed to check the valve clearances. At the same time, the opportunity was taken to clean under the rocker cover bolt seals. The valve measurements were taken and are as follows:

Inlet 1:           0.12

Exhaust 1:    0.15

Inlet 2:           0.1

Exhaust 2:    0.23

Inlet 3:           0.11

Exhaust 3:    x

Inlet 4:           0.1

Exhaust 4:    0.25

The measurements taken are all within spec with the exception of the exhaust valve on cylinder 1. However, the inlet valves are all on the borderline of going out of spec. It was not possible to see the sizes of any valve shims, as a valve shim tool to depress the valve baskets and remove the shims is still being procured.