nr's blog

Centrefold 26 March, 2015

Filed under: Motorcycling — nr @ 11:07 am

Well, it’s been a while since I posted anything. I think my normal winter hibernation kind of set in a bit more deeply than normal this year, and I’ve not really been up to much. Well, that said, I’ve planned another trip to The Alps this year to pick up where we left off last year. Hopefully without all that tedious mucking about digging ourselves out of an avalanche. And I’ve been playing a bit with Project Adequate ZXR – which is now slightly more adequate than it was before.

First up, mechanically, I’ve finally sorted out a carburation problem that has been driving me potty. The bike would run cleanly for about 15-20 minutes or so, but as soon as it got fully warmed up, it felt for all the world like an air leak between the carbs and inlet tract. It wouldn’t idle without constant blipping of the throttle, and then the revs would hang up at about 4000rpm before slowly dying. It was horrible. What I couldn’t work out though, was why this only happened when the engine was warm? I had the carbs out, stripped, and ultrasonically cleaned about 50 times. I removed, inspected, cleaned, and re-bonded the inlet rubbers to the head. I forget how many times I balanced the carbs. I reset everything back to factory settings. Still the problem persisted. I was about to either sell the thing, or set fire to it, when I decided to balance the carbs again, and noticed something. The horrible little rubber bungs that blank off the vacuum take-off spigots that are used to connect the carb vacuum gauges; two of them were not quite as snugly fitting. So I threw them away, and bodged something together out of some old plastic tubing and a few guttering screws. And it seems to have fixed it. I say ‘seems’ as I’ve only made it out for one ride since making the change, but it felt much much better, and crucially, after a half hour ride, it still felt good. What I think was happening is that the plugs were becoming more flexible as it all got toasty warm down there, and eventually, one (or more) of them started leaking air. It’s not a problem I’ve ever even heard of before but it seems to fit with the symptoms I was experiencing, and went away when I replaced them. Fingers crossed that the problem doesn’t come back, as I’m pretty much out of ideas otherwise.

Part II of the operation to make the bike nicer to ride came about courtesy of a lucky eBay find. I never really liked the exhaust system that was on the bike. It was loud, offensively so, and I think that the open can didn’t help with the carburation either. And then, bouncing around eBay one evening, I found a lovely stainless Micron road system for eighty quid. To be honest, I probably would have paid that just for the can, but this was the full system, in remarkably good condition. I also had the pleasure of a quick whizz up to Sheffield to collect it from Nick, who has just finished restoring a green ZXR H1 to original condition. So, with that fitted, I can now ride through town without the bike either cutting out, or scaring old ladies and small children.

P1050411Also worth mentioning that the bike was featured in Practical Sportsbikes magazine recently. Sadly this was before the carbs and exhaust were sorted out, but they still seemed to like it. I was asked to put the standard bodywork back on for the photos, which kept me occupied for a couple of hours, but other than that, there was no preparation at all. They phoned me up, asked if they could have the bike for a few days, thrashed the spuds off of it, and gave it back with a full tank of petrol. Back in about 1986 or so I started reading a mag called Performance Bikes, and at the time, thought how cool it must be to have your bike featured in a magazine, let alone on the cover. All I will say now is that it hasn’t led to offers of TV appearances or a job spannering for Valentino Rossi.


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