Tuesday, 26 July 2016

The Great Vowel Shift

A couple of weeks ago I had to do a day of work in the far-east (of London). I'm from the South-West (of the country), trying to talk to the Mockneys gave rise to some fantastic misunderstandings. I said to the woman I was staying with that I had to wear a "whistle". I meant "suit" but she thought I meant "referee's whistle" and as a primary school teacher she offered to lend me one.

The meeting was in a building with a name like "Sewcraft House". Unfortunately the address had been transcribed by somebody at my company too used to talking to people with farmers' accents. They'd recognised long rounded second vowel as an 'o' and written it down as "Sewcroft".

My favourite was a waitress in a pub who really seemed to be telling me that there was a "Steak and Owl" pie – which I would have tried.

Richard "steak and ale" B

Thursday, 21 July 2016

TMax Fever

This article is about hot weather starting on the Yamaha XP500. You can ignore it if you're here to read about the stupid and embarrassing things happen to me.

There is a much discussed phenomenon where the TMax will run poorly or not start in very hot weather, or will not start in direct strong sunlight after it has been parked for a few tens of minutes. The received wisdom is that the fuel pump doesn't work at high temperatures and starves the engine.

I have a different idea, and a little evidence to back it up.

Hypothesis

TMax fever is simply a symptom of a weak battery. When the coolant gets over temperature the bike runs a large electric cooling fan. The current that the fan draws pulls the battery voltage down and the bike either refuses to run the fuel pump, or the fuel pump runs ineffectively. 

Supporting evidence

My Tmax has failed to start in hot weather on three occassions. The engine turns over but it never fires.

I know for sure that the battery was on the way out, but I was too cheap and lazy to buy a new one.

When the cooling fan cuts in it's loud, on the most recent occasion I could hear the fan labouring and its pitch changed with engine revs - it was getting more power when the engine was turning the alternator.

I'm unconvinced that the fuel pump itself can develop a temperature sensitive fault and recover when the temperature drops, but we know that there is an accurate thermostat in the electrical system - the one that turns the cooling fan on.

But if the battery is borderline-fucked how do you keep starting and riding the bike?

As soon as the bike is running, battery capacity is almost irrelevant, all the power comes from the alternator. TMax's are remarkably easy to start. They only have two cylinders and those have a low friction ceramic lining, there's a heavy contra-piston storing up energy like a flywheel, it's got semi dry-sump lubrication, and the ecu is brilliant. I bet it waits until the engine is up to speed and richens and retards like crazy to get the first spark to spin the engine.

I've been riding to work for months a bike with such a knackered battery that it can't keep the luggage locker light on for more than a couple of hours.

Further experiments


I've now got a TMAX that is susceptible to the fever, but that has a brand new high-quality battery. If the temperature ever gets up to 30 I'll ride it until its hot, park it in the sun, and then see if it starts half an hour later. I'll update this article with any results, but sadly I live in the ancestral home of grey tepid weather.

If anybody gets a TMAX turning over but not starting in really hot weather, please try to get some jump leads on it and let me know what happens (in the comments). You need a phillips #2 screwdriver, a 10mm spanner, and about 20 minutes.

Richard "Fever isn't such a new thing, fever started long ago" B

Updated summer 2017

TMAX Fever is a symptom of a faulty fuel pump. I have seen the ECU put 12v onto the pump when I turn the key, but the pump didn't run and the bike didn't start. Ordinarily when you turn the ignition on you can hear the fuel pump running under the saddle for 2 seconds. If it has overheated then it doesn't run and the bike won't start. You can buy a pump on amazon or ebay. getting the pump assembly out of the bike is time consuming. Prising apart the assembly and changing the motor is challenging.
look here and here for more information about my struggles with TMAX fever.

Wednesday, 20 July 2016

Push

About twenty years ago I had to move a broken down motorbike from Marsh Mills to Furzehatt Road. I took two friends with me and managed to push it home easily. In all the time since we've barely stopped taking the piss out of the weaker friend because even though he didn't take a turn pushing the bike, the walk was too far for him. I ended up letting him sit on the bike while I pushed both home.

I'm not as fit and strong as I was back then, and my motorbike is much larger and heavier. Yesterday was the hottest and sunniest day I've ever seen in Plymouth, my bike broke down – again near Marsh Mills. I had the whole afternoon to myself and thought that I would be able push it home. I was wrong, when I started the steep climb to my house I got faint and unstable on my feet, nearly dropped the bike on myself, and had to ring up friends for help. I'm now sunburned, blistered on hand and foot, the bike doesn't start, and I'm not walking around with a massive sense of physical achievement.

Richard "how much does motorcycle recovery cost?" B

Pratmobile

This weekend I either made a new friend or annoyed a stranger for a couple of hours. I certainly revealed myself to be a hypocrite.

I'm very keen on the Renault 4 (I'll explain why in a future instalment) and I bumped into a man who is working on a very rusty one. After all my complaints about weirdos wandering into my garage and talking at me about cars I did virtually the same to this poor gent. In my defence I did lend him the workshop manual, and I put on dirty clothes and spent a couple of hours under the car with him compressing and removing the rear shocks and starting to get the trailing arms off.

Richard "cable ties and ratchet straps" B

Tuesday, 5 July 2016

Restaurant Review

This Saturday was the third meeting of 2016 restaurant club and we ate at Maratimo on Plymouth Hoe. I thought it was fantastic, but I don't know if that was the restaurant, or the fact that I've never really eaten at a tapas place before. It's hard to find the restaurant, and once you have its hard to find the door. The entrance is unwelcoming and the dining room wasn't quite as nice as I was hoping. The view is fantastic Рor would have been if the weather was good, and the food and drink were even better. We ordered dozens of dishes from a ridiculously cheerful Spaniard and they arrived in a steady and delicious stream until we were full. My favourites were the sardines and the squid... until we started ordering desserts... Freshly fried churros and crema-catalan were wonderful. Crema-catalan is basically a cr̬me-brulee, but with a less rich custard. Mine was flavoured with orange and served with candied peel.

I ordered a paella, but the experience wasn't what I expected. As it was a Spanish restaurant I had expected to be warned sternly that it would take at least half an hour, and then a scalding charred paella pan would be balanced before me on a makeshift refractory trivet. In fact it was in a china dish, and it came too quickly to have been cooked specially for me.

Richard "the first rule of restaurant club" B