1987 Yamaha SRX-6: Our bikes

Date 15.7.2013

Presented by
  • Motorcycle Trader

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1987 Yamaha SRX-6

HEAD CASE

A nice simple single-cylinder powerplant – what could possibly go wrong? Guideo soon discovers that home mechanics and roofing bolts don’t mix…

It was one of those absurd situations and a warning never to feel smug. Muggins was riding home on Sonny the SRX-6, quietly pondering how much fun it was. Cheap, simple fun and a whole lot less trouble than some of the twins and multis in the shed.

About the time this raised a contented smile on the dial, I couldn’t help but notice a weird ‘braap’ noise as we accelerated away from the lights. Had the exhaust header wound loose again? Nup, it was much noisier than that. The bike was still running, but it wasn’t happy.

Okay, so let’s start thinking of what would be the most inconvenient cause – something that would entail an engine tear-down. Head gasket? Now we’re cooking…

In case I needed further confirmation, a quick blip of the throttle from cold the next morning revealed a puff of smoke from just under the head. Terrific.

With Winston the 1947 Sunbeam (aka Igor the Conrod Thrower) occupying limited shed time, I cheerfully shuttled the latest little disaster off to the ever-patient and often somewhat bemused Ash at Stafford Motorcycles.

SIMPLE SONNY

A head gasket change on an SRX should be a simple process. It’s a straightforward air-cooled, singlecam, four-valve head. But of course there was a catch.

Old bikes will have inevitably passed through a series of owners, some of which do the servicing by the book and some who probably should not be let loose with anything more complex than a chopstick.

So I got the call – the one where the shop owner (young Don Stafford, in this case) starts the conversation with the words: “Mate, y’know that SRX of yours, well…” And you just know it’s not good news.

Usually, by this stage, I’m expecting my caller to tell me the model I have is a bit of a rarity (a Japanese domestic model in this case – usually it’s far worse) and the required part is only made by retired Latvian sheep herders on Shrove Tuesday, so it could take a while (not to mention a bucket of money) to get one.

For once, it wasn’t all that bad. It seems a previous ham-fisted owner had stuffed the threads on two of the head bolts and had used what looked suspiciously like roofing bolts to get a bit more reach. That, in turn, probably had a lot to do with the gasket failure.

BACK IN BUSINESS

It was hardly the end of the world. The lads got stuck in with a helicoil kit, replaced the hardware-store items with factory bolts, cleaned up the head and reassembled it. …a quick blip of the throttle from cold the next morning revealed a puff of smoke from just under the head.”

In a perverse way, I’m almost pleased it happened, as I now know we have a nicely cleaned-up top end that is healthy. It wasn’t a very expensive exercise and it’s likely that’s the last time we’ll see inside that powerplant.

The bike has gained a bit of performance sparkle that was previously missing and everyone walked away happy and uninjured – a good result.