Featured 1964 Tiger 90 Restoration

Should be ready tomorrow! Finished the tank and front mudguard spraying today in not ideal conditions as it was damp weather. Some bloom in the black paint on the tank but a light sanding with 1200 wet and dry and a few coats of lacquer and it looks great. Brought the tank indoors to dry nicely overnight. Also persuaded that little oil pipe on that connects the return to the rocker box oil feed. All clamps and nuts checked for tightness. Brake light switch fitted and all electrics working. Tyres pumped up. Odane is going to help get it off the ramp and (he doesn't know this yet lol) push it up and down the road to get the oil circulating before we fire her up. Exciting times!

 

Ready to run tomorrow! I've left the cover off the primary drive so I can adjust the clutch and fine tune the ignition timing during the break-in run which should be tomorrow weather permitting.

 

Nice weather this Monday morning so got the bike off the stand and ready to go. Odane came round for the start up. I was confident it would go in 4 kicks but nothing. Not a chuff. Exhausted and hot I took off my riding gear and had another go. The oil pressure tell tale was showing oil pressure so that was one good thing. We decided to check for sparks but couldn't see any (this is a characteristic of this type of electronic ignition - high voltage, short duration spark, difficult to see). Odane held a plug against the cylinder head. I kicked and he got one almighty shock! It sparked
So it must be fuel. We took the float bowl off. Bone dry. I jiggled the float needle and fuel flowed. With that sorted a couple of kicks got her going. After a bit of running we saw that oil was returning to the tank so I rode off for the break-in.
It's about 3 miles to the A1(M) then on the motorway I gave her some stick. Full throttle in third gear to 6000 rpm then snap shut the throttle. Repeat a few times then do the same in 4th gear for 2 motorway junctions. Return home doing the same thing. This puts maximum gas pressure behind the new rings to bed them into the freshly honed bores. I'll do a couple more break in runs like this then change the oil and filter and have a great running bike that doesn't burn oil.

 

Thanks. The Blazer will be on the stand next. It's stuck in 4th gear with a broken gear selector leaf spring. So much work has gone into that bike...

 

Removed the sump plug to check for debris after yesterday's break-in run. As you can hopefully see from the photo there were some iron fillings in both the filter gauze and stuck to the magnet. The oil that drained from the sump had swirls of fine sparkles in it. All that after only 16 miles! I dipped some clear tubing into the oil tank and that came out clear so the oil filter in the return line is doing it's job.

 

Thanks!
I have to get the primary chain tensioner on. I forgot to fit it before the Electrex World electronic ignition stator and rotor.
Tried to get the rotor off to then get the stator off but I could not break the taper. I made up a puller and applied as much force and hammer tapping that I dared but could not shift it. Instead I filed a semi circular relief slot in the aluminium stator backplate such that I could slide the tensioner blade on to its spigot. Took a while and I had a lot of shavings to clean up. Trial fitted the tensioner but there was a 7mm clash between the tensioner and the stator so I had to grind that 7mm or so off the tensioner blade. Hopefully you can see this in the photos. I will give feedback to Electrex because a small amount of milling by them would allow the unmodified tensioner blade to be fitted either before or after the stator.

 

What an idiot! The primary drive chain tensioner already has a cutout and I was fitting it the wrong way around. Duh! New clutch springs arrived today so I fitted those as one of the original springs was weaker than the other two. Got the primary drive cover on and poured in some automatic transmission fluid.
Went for a ride but there were problems. It was hard to start. Around about 3000 rpm there was a horrible resonant noise which turned out to be the fuel tank bolts being not tight enough. The tank is a structural part of the frame - bad idea!
The carburation is definitely off. The pilot jet feels too rich but I've just been down to check but the air screw was only out one turn. The mid range also feels rich so I'll drop the needle tomorrow and see how that goes. It might sort out the low speed running too. The (brand new) plugs are soot black so there's work to do.

 

Champion N3C / OE068/T10 COPPER PLUS Spark Plugs which I saw recommended somewhere.
The PWK carbs are cheap £25 ish and really good having chrome plated flat slides. The one I have on the T90 came from the USA ready to fit with the correct Amal type flange. As standard they are rubber mounted similar to Amal mk 2 Concentrics so on my Trail Blazer I had to make a flange from 8mm Aluminium (lots of drilling and filling) then bond it to the carb with JB Weld. The main and pilot jets are easy to change by dropping the float bowl and you can buy sets of jets cheaply on eBay. I have had good results with Amal carbs too but have never been confident with their idling. The idling of the PKW is super reliable.

 

Went for a 40 mile ride to my mum's in North London. All good through Stevenage blasting round the roundabouts. On to the A1(M) and gradually a misfire set in. Just managed to keep the thing running to the Shell garage at Stirling corner where I put in £10 of E5. All good through Bushey but then more misfiring. At mum's took the float bowl off and cleaned it though not too bad. Turned the fuel on and the flow was really slow. Jiggled the float a bit which seemed to improve it. On the way home the misfiring got progressively worse until it stopped. I took the float bowl off again and it was dry. The fuel filter was blocked with rust dust. I had enough tube to bypass the filter and then it ran great. Later on I dropped the needle to the leanest position which really livened her up so gradually sorting things out.

 

Fitted a new fuel filter and went for a shakedown run. Difficult to start and to keep running until it's warmed up a bit. I suspect a blockage in the starter enrichment circuit. All was good once warm except for slightly rough low speed running. I stopped and adjusted the air screw until it seemed better then rode about 10 miles with no problems except the speedo is barely flickering off the stop. On the way home I went for the front brake but the lever was loose. The pivot bolt had fallen out. Successful shakedown ride! The front brake doesn't do much anyway...

 

The mixture is about right by the spark plug but I'm tempted to put the concentric back on while I thoroughly clean the PWK.

 

Went for a night ride to adjust the headlight. Hard to start from cold which I suspect is a problem with the PWK enrichment circuit. I'm going to fit the old Concentric and get that working better than it used to and service the PWK in the meantime. I got the (LED) headlight adjusted and it is actually quite good however the blue main beam (LED) warning light is way too bright. The speedo flickers just above the stop. I disconnected the cable at the back wheel and spun it with my electric drill and it worked perfectly so the drive box needs attention. Still plenty to do...

 

Spent some time cleaning the Concentric which wasn't too bad given it hadn't been used for years. Fitted it, tickled it and she fired up first time. The spec is 190 main jet, 25 pilot, air screw one turn out, 106 needle jet and the needle in the leanest position. No air filter. Went for a ride and all seemed good and lively. Stopped to adjust the idle and air screw and she conked out. Much kicking and nothing. Tickled in desperation and she started again. Managed to find a sweetish spot for the air screw and idle. A bit fluffy and snatchy at slow speed but I have a fix for that I'll do later. Back home got the air filter on so will need to test that next.