Featured Tiger 90 Rebuild

Here is an oddity. Page B28 of the Triumph service manual is blank. Page B27 ends mid-sentence and B29 starts with a new section, so I suspect page 28 was not printed. There is also information missing about working on the timing side.

 

Thanks! Yes, that has the info.

 

Here is the inside of the timing chest. The sad news is that the engine cannot be turned over with a spanner on the end of the crankshaft. Also, I need to check the spares book to see if there is a locating dowel, as there is a hole for one, but none was found. The remains of the cover screws that had to have their heads drilled off can be seen.

 

Advance retard unit is all good, just needs a light clean and a drop of light oil on the pivots and centre shaft. Advance in degrees - 12 - is stamped on the back.

 

Oil pump is off. The plungers move up and down with no discernible play and it still pumps oil. I will leave it soaking in oil to keep it “wet” before inspecting it properly. I prefer the plunger type oil pumps as they are less prone to wet sumping than the gear driven type.

 

Crankshaft end nut and clutch centre nut loosened, ready to take apart this side of the engine. The locking tabs on both nuts have been re-used several times, so this has been apart before.

 

Record of the wiring before I pull it through the case. The green and black (don’t they make chocolate?) and the green and yellow were joined in a double connector, the white and green on a single connector.

 

The quick workshop test for magnetism in the rotor is does it stick to a vertical steel plate and support it’s own weight? Yes it does.

 

Ready to pull off both sprockets and chain, with extractors (not shown).

 

The clutch came off, leaving the centre boss in place. The twenty clutch rollers fell onto the cloth I left in place to catch them. I looked at the rollers and thought 1/4” by 1/4”. Oh no they ain’t. They are 1/4” by 15/64”. Why?
The thrust washer looks a bit worn.

 

Puller on the end of the clutch boss. It’s an MCA P109 (stands for Motor Cycle Accessories, Puller number 109, I assume).

 

Down to the inner primary case. I need to grind the blade thinner on a screw driver to make it fit the narrow slot on the head of the six inner cover screws.

 

Needs a new gearbox sprocket. The mainshaft has a tiny amount of end float which is to be expected. No movement up or down / front to rear, so the gearbox bearing is a good ‘un.

 

Turn back the tab washer, lock the sprocket with the chain and get the big socket on the nut. Things are moving well today.

 

Sprocket off. The bush on the fourth sleeve gear has grooves on it from where the oil seal has rubbed it. It will need replacing too.

 

Let’s be careful out there I wear nitrile coated work gloves which protect from little knocks, but that’s all.

 

While undoing the nuts on the end of the camshafts a little bit of movement appeared on the crank and the pistons moved a bit in the barrel. Cautiously, the wiggle turned into up and down movement and the pistons were freed up. After a bit of persuasion the barrel came off.