Featured Tiger 90 Rebuild

Gearbox sprocket nut on, and tab washer turned up. Checked the end float of the mainshaft, which is 2 thou of an inch. Can’t find a reference figure for this in the Triumph workshop manual.

 

Inner primary cover on, spot of loctite on the screws.

 

Changing the rubbers in the cush drive which have started disintegrating.

 

New thrust bearing as the ears had worn off the old one. Then on with the clutch basket, rollers, primary chain and sprocket.

 

Then on with the clutch centre and the dished washer, locking tab and nut. Have yet to tighten the nut and lock the tab.

 

Clutch centre nut torqued to 50lb/ft as per the Triumph workshop manual. That’s a lot of torque, in fact it’s the highest for any nut on the bike. The torque for the alternator nut is a more pedestrian 30lb/ft. Sod’s law meant that my good torque spanner died while doing this, and i had to use the back up old one, both are in the pic below.

 

Clutch now on, but final adjustment of pressure springs yet to be done. Also, i haven’t put the push rod in, as what usually happens is when i move the engine around it falls out.
Clutch plates were all in very good condition, flat with no wear on the dogs and corresponding slots in the basket and centre were good. The stack of twelve plates (six plain, six fibre) should be 1.40” in total. This stack, when cleaned and dried is 1.385”, so in total has worn down by 0.015”, which is good enough to use.
The primary chain and sprocket teeth on the clutch basket and crankshaft sprocket show some wear, but again, still have lots of life in them and will be re-used.

 

Stator now attached. Triumph workshop manual says the three securing nuts to be at 20lb/ft.

 

Engine oil pipes have rusted through.

 

The rusted section with holes is on the long flat part of both pipes, the pipes near the mounting block are all right. i could save a few quid by cutting the rusty pipes off and just adding longer rubber pipes. Feels a bit like a bodge……, any opinions out there?

 

Thanks, that’s good information and sound advice. also better than my plan B of brazing new pipes on.

 

Small jobs on the underside.
1. Replace the sump drain plug, with its spring, cork seal, gauze and fibre washer. The cork seal was missing from the gasket kit, but a hand made one sufficed.
2. The gearbox drain plug and level plug are in place. The level plug is loose as i will need to take it out later.
3. Breather pipe added. This is just a bit of petrol pipe.
4. New bullets soldered on to the alternator wires. I joined the green-black and green-yellow wires into one bullet, as it seemed more efficient.

 

Working on the timing chest.
1. New oil seal in the timing cover.
2. Dowel fitted to the cases, as it was missing.
3. Oil seal fitting tool used.
4. Oil pump cleaned, tested and fitted.
5. Oil pump nuts tightened to 6lb/ft.
6. Not too much gasket goo.

 

Put the cover on, and screw it down with new screws. All the new screws were 1/4” too long and had to be cut down to fit. Little bit of polish on the cover, but not too much or it will look too shiny and out of place. That’s it for today.

 

Gearbox outer cover cleaned up and checked.
Advance retard unit cleaned, checked, oiled and installed.
Oil pipes renewed - the transparent pipe is the return pipe, as it always good to see oil returning to the tank.
Clutch pushrod installed.
Gear indicator pointer put back on.
Gearbox outer cover on. Kickstart works OK, and all gears select.

 

Points and timing completed today. Lots of messing about with tiny little parts and no wiggle room. The ignition timing was set statically and will be strobed when the engine is running. If i’ve done it correctly then in the picture, the right hand points are just opening at 14 deg before TDC on a compression stroke in the left hand cylinder. Advance retard unit in the picture is not advanced.
New condensers, and the old points cleaned up all right so i used them.

 

Although the pistons were seized in the barrels, they came free with a good soaking in petrol and after inspection they are within tolerances and are not damaged or scored, so i intend to re-use them.
The piston rings were gummed in the slots and came out in pieces. New rings have been bought and will be used.
The barrel cleaned up all right. There is no major wear and only some small score marks which can’t be felt with a fingernail, so not deep.
The barrel has been cleaned up on the outside and especially inside on the bores. The bores have been honed.