Previously in TRX world I rebuilt a dead engine, then killed it on the dyno, then fitted a new engine and killed that one too. On the face of it, things weren’t looking too great really, but I’ve always liked a challenge. And the opportunity to properly re-equip my garage and build a good engine was really too good to miss. Essentially, this is exactly what happened. As we left things last time (quite some time ago now, sorry, I’ve been lazy) I’d collected two spare derelict TRX850s, and stripped the crank and shells from the best one to put into my engine. The rest of the rebuild went surprisingly smoothly. I took the opportunity to give everything a really good clean up, and replace gaskets and seals all over the place while I was in there, to hopefully give the engine the best shot at a long and happy life. I also swapped the clutch plates and steels with some of the huge collection of spares, as they measured up with a bit more life in them.
The one thing that I did kind of bodge my way around was the charging wiring circuit. Way back in the mists of time, the connector from the alternator to the loom got a bit hot and melty, so I just hacked it out and soldered it in place, with a view to replacing the connector at some point. This bodge worked so well that I completely forgot about it until the latest round of engine work, and so I just replicated the bodge this time too. I’m not expecting to pull the engine again any time soon, so it seems like a reasonable course of action.
Oil pumps were also carefully measured several more times, just in case I was missing something stupid that was the cause of the big end failure, but every time I measured them, they came up bang on spec, so I just had to trust the workshop manual rather than my gut feeling. A factory of Japanese engineers will always have a better formed opinion than an idiot in a shed. So with the engine rebuilt (again) and reinstalled (again) it was time to run it up to temperature. And I’m glad to say that this went completely without incident. Nothing untoward at all. No smoke, no clonks, no strange whizzy noises. Just that lovely offbeat rumble that the TRX is famous for. The MOT had expired by now, so I couldn’t really take it out for a test ride. Instead, I booked it in for a session on the dyno and a new MOT at Cambridge Motorcycles. Was I nervous? Hell yes. Given what happened the last time I put it anywhere near a dyno.
Now, with that said, it *did* make an easy 77bhp before the clattery thing- which may not sound a lot, but this is a famously realistic dyno. I’ve seen a few ‘200bhp’ bikes make about 180. And my old TZR made 55 [1], but regularly outdragged other bikes supposedly making 60. And therein lies a lesson – a dyno should be regarded as a comparative, rather than an absolute tool. (Of course, the person with the bike can always be considered an absolute tool). So one wet and windy morning, I hopped on the bike, and rode to the petrol station to fill up. I mused on the fact that the previous tank of fuel had actually outlasted three engines as I continued my journey into Cambridge. The bike felt great on anything more than about half throttle. Tootling around through 30mph limits it was definitely feeling a bit snatchier than before. But that’s the idea of setting things up on the dyno, to check the fuelling and make sure that it’s not running horribly lean anywhere.
“It’s horribly lean on the needles” said Spike after the first run. And it was – but the lovely thing about the FCR41s is that changing the needles is a two minute job. So over the course of the next three dyno runs, we lifted the needles three notches, and while it was still slightly leaner then I’d ideally like, we’d run out of adjustment and anyway, it was a million times better than before. The torque curve was beautifully flat, and the noise from the Projection Components 2-1 system was truly noteworthy. There was a bit of an oil drip – I think it was from the water pump o-ring. Certainly from that area of the engine. It may have been there forever, as this is the first time I’ve ever seen the thing running hard at a standstill. After three runs, we were done. Fuelling on the mains was spot on. Like I said, slightly lean on the needles, but we were out of adjustment and it was marginal, so nothing to worry about.
The bike rolled off the dyno, and into the MOT bay where it passed with flying colours. The ride home was lovely. The fuelling was definitely way better on the needles now, and I made a mental note when I had a few bob to maybe look for some different tapered needles to tidy things up that last little bit. And anyway, the bike was originally set up for the Renegade 2-2 system, not the PC 2-1, so it’s hardly surprising that things were a little snatchy. 41mm flatslide carbs and a 2-1 system are never going to be brilliant trying to hold 30mph at 2000rpm.
So that was it. The original plan, a year ago, to just take the thing off the road for a few weeks for a winter refresh had gone completely out of the window when I discovered the damaged valves, and then the big end let go, etc. It has been a brilliant journey of discovery, and truly made me realise how much I love this bike, as I would have just walked away from pretty much anything else. So, I did the only sensible thing in the circumstances, and loaded the bike and all the spares into a large van driven by my mate Jack, and sold the whole lot to him.
Ready for the next installment?
After riding James’s 675R at Cadwell a few weeks ago, I knew what was coming. I’ve wanted to ride a 675 for ages now, and it was an itch that just needed to be scratched. And once I’d ridden the 675R, I couldn’t just walk away. The same as the first time I rode the TRX, all those years ago, also at Cadwell Park. Besides, I’ve never owned a triple. I’ve had singles, v-twins, parallel twins, v-fours, inline fours. But never a triple. It looks lovely in the photo, but there’s a few little things that bug me. Notably the missing pillion pegs (already have some being delivered), the slight mismatch in paint between the fairing panel and the nose (it’s been resprayed at some point, and although they’ve done a good job, the pearlescent finish just doesn’t quite match), the ludicrously small number plate, and the shonky levers. The paint, I’ll leave alone – it’s close enough. The levers I’ll change to a set of stock Triumph ones at some point. And yeah, of course, the number plate will be changed to something far less likely to result in a nicking.
Off to the garage I go then…
[1] I’ve just gone back through my old notes, and actually it made 48.
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