Featured Refurb On The ‘69 T120.

This is my ‘other’ bike, a T120 Bonneville which I last used in 2000 and has been laid up in the back of my garage since II completed the National Rally that year doing about 1000 miles over 24 hours to get a silver medal and missing out on the gold by just a couple of checkpoints. When I got home the bike went in the garage and to my eternal shame I haven’t ridden it since. Uncovering it the other day it’s certainly showing a lot of deterioration from lack of attention and needs a lot of tlc to get it back at least to a rideable condition.

Over the years since, for one reason and another, I haven’t touched a motorcycle until I started in on the T100ss that has also occupied space in the same garage, but in boxes which I naively thought was a ‘mostly complete’ bike. At the moment I think I’ve pretty much run out of patience with it, although it will get finished but maybe not in the original timescale I’d set myself.

So.. although I know it’s probably a stupid thing to do, and as my efforts with the T100 are pretty much getting nowhere, I’m going to turn some of my attention towards a bike that I know is at least one complete entity and that I’ve got some sort of chance of turning it back into a going concern.

 

Close up it’s looking a bit sad I’m afraid. Needs a lot of tlc. My fault. Rear shocks are ok though.

 

Well, I can’t vouch for what happened to it before I got it but I haven’t changed much. The silencers weren’t originals and were pretty ropey so they got changed. I put Trophy TR6 ones on as I liked their look better than the longer originals. And of course the rear shockers which weren’t doing much at the back. Otherwise it was just routine stuff.

 

Oh Wow! That’s somethin’ else.

 

Ha! I’m not crazy enough to think I could manage anything like that. I really don’t need a second pile of junk in the garage. I’ll settle for something that moves under its own steam.
Still, it’s up in the air now.

 

Hi joe. Thanks for your comments.

I’ve seen the postings on some of darkman’s other motorcycles and they’ve all been of the first water. I think I’ve gleaned quite a bit from the postings he’s shown but I don’t think I’d get anywhere near the quality of his work.

Back in the day Ive usually tried to keep the Bonnie as near to original as I can although I’m not averse to changing if I thought there was a benefit. Shamefully I’ve let it deteriorate where it’s now going to require a major effort to get it back to rideable.

There were however a number of items even then that required attention. They haven’t improved with age and despite knowing that it’s pretty dumb to try to do two projects at the same time I feel that it’s time the Bonnie got some attention before it gets too far to reclaim.

Even back then one of the changes I had in mind was to replace the discoloured spokes for stainless steel. They never cleaned up very well and always looked a bit second hand. There was also several chromed bits including the chrome on the front wheel rim and knave plate that were rubbed through.

Fast forward to the stalled Tiger refurb. That didn’t come with any wheels, only the hubs, I’ve now got in touch with a local (ish) gent who is going to supply and build up new wheels for it. The problem is I’m supposed to supply the originals intact so he can measure the offset of the wheels to the hubs. Which is where the Bonnie comes in. As I don’t have complete wheels I’m hoping to kill two birds by taking out the Bonnie wheels to let him measure them and apply those figures to the Tiger set up. Then rebuild the Bonnie wheels with new spokes and a rechromed front rim.

Effectively that’ll kick off refurbing the Bonnie as well. It’s up on a stand atm and I’m looking at a list of what’s going to be needed.

Yikes.

 

I’ve pulled the Bonnie out of its corner of the garage where it’s been hibernating and started poking around to try to find what work might be necessary and the extent of the damage. Apart from the obvious I found at first that I couldn’t get the engine to turn over on the kickstart and the clutch wouldn’t separate, so it looked like a major engine strip for a start, apart from anything else.

I’ve started draining the oils to find that most of the engine oil has drained into the engine case. Removing the plugs, the r/h one was reluctant to turn in the threads so I applied some penetrating oil overnight which eased removal without bringing the thread out with it. I applied some oil to the cylinders and tried turning the engine over on the kickstart, and to my surprise, it did. It appears to spin over quite freely on the kickstart although the clutch still seems to be stuck. I took the Endoscope to the cylinder bores but I can’t discern any corrosion or scoring, so maybe it’s all not quite so bad as I thought it might be.

I drained off what was left of the chaincase oil and found the casing gasket had deteriorated enough to let me pull bits of it out without removing the bolts. The gearbox oil is going to have to wait for a while as the lifts mounting bar is covering the bolt head.

The front fork drain plugs are out but precious little oil came out after. The fork seals are old but there doesn’t seem to have been any leaks. The seal holder chrome is poor and the paint on the sliders is dull and chipped, so it looks like another forks job. At least I’ve had a bit of practice on them. I need to get the petrol and oil tanks out next to clean them out.

There’s a m/cycle jumble at Kempton Park this weekend so a good opportunity to get some oils of the right vintage.

 

The petrol tank came off reasonably easily after cutting back the old hardened pipes to the carburettors. Surprisingly the tank mounting rubbers were still soft and pliable, but they’re not going to go again. Equally surprisingly, since I’ve never had to take the tank off before, there’s some damage to the underside paint and the tunnel’s welded seams is distorted outward. It also looks like there might have been a tea break between painting the left hand and the right hand white coach line to the underside. I had thought the paint was original. I’m not so sure now.

The interior of the tank is very rusty. So far I’ve swilled it out with about 5 litres of clean petrol and removed a whole lot of powder like sediment and there’s still a bunch to do.

 

Thanks for that info darkman. It’s really quite amazing! The carburettor cables and loom are bundled either side in that area and taped to the frame and only just clear enough to get the tank off.

The coach line does seem to follow the colour split both sides and they’re very similar thickness It doesn’t look like an add-on but I suppose a right handed painter, under pressure, might not get it quite even handed.

The rubbish in the tank is coming out slowly. but there’s still quite a bit to go. I’ve had vinegar and bolts in the tank for a couple of days (shaken, not stirred) but there’s still quite a bit to go yet. I might try the electrolysis method if it doesn’t come out in a few more days.

I’ve still got to get the oil tank out yet. There was hardly any oil left in the tank, it was almost all in the crankcase. I dipped what was left in the tank but it doesn’t seem particularly sludgy. I’ll check it further when the tanks out.

 

24/9/24

After about four days with the petrol tank filled with undiluted White Vinegar and doing the Hokey-Cokey every few hours it’s made an impression on the rusty internal surface which seems to be now cleaning up quite well. Most of the loose rust and petrol sediment flushed out with a few litres of petrol but the surface rust is taking a bit of moving. The first couple of days just seemed to be making things worse. Eventually the silver patches have spread out and joined up, but there’s still a way to go yet.

As I’m still up to my elbows in vinegar I’ve taken the opportunity to re-do the Tiger’s tank which I didn’t think I’d done very well a few months ago. So now I’ve got two tanks on the boil and I think the neighbours are wondering wth I’m doing in the dark at the bottom of the garden in the late evening. They’ve probably come to the conclusion that I’m running an illicit still. I don’t think they understand the complexities of being a vintage motorcycle owner.