‘Smashed engine cost £1200 to fix for the sake of a £150 chain’
Mechanic Niki Spreng’s warning that an R1 needed a new chain went unheeded
When it comes to DIY it’s always tempting to put off those boring jobs like clearing gutters or a drain, but then the rainwater starts lapping at your front door and you start getting ‘I-told-you-so’ looks.
Sometimes it’s the same with bikes. When a customer brought his 2005 Yamaha R1 into NS Motorcycles in Aylesbury, mechanic Niki Spreng immediately spotted an essential job that needed doing.
Niki said: “I could see the chain and sprockets were on their last legs and told him he needed a new set. He said ‘yeah, yeah, I’ll get onto it’ and headed off.”
It was only a few days later that Niki got a call from the owner who reported that the chain had snapped. “He said it went at about 45mph, but when I saw the state of the engine I suspect he was going a bit quicker than that,” Niki added.
It looked like the chain had snapped on the bottom run which meant that the front sprocket continued to pull the chain forward so it wrapped itself around the cog, bending the gearbox output shaft and punching a hole in the crankcase.
Niki was horrified: “When you picked the engine up you could hear bits of the engine rattling around inside the cases, as the chain reaction smashed up the teeth on four of the gear ratios.”
As well as replacement crankcases, output shaft and gear ratios, the engine needed new crankshaft shells as well as all the necessary gaskets. If the parts list had used new Yamaha components it would have topped £3000, but the owner managed to source some crankcases for £300 and the gearbox parts were located for £250, which brought the total bill down to £1200. All for the sake of a £150 chain set. Niki concluded: “It had been a £3000 motorcycle, but with that hole in the cases it was worth about £3.50.”
‘With that hole in the case the R1 worth £3.50’
The snapped chain smashed the crankcases
If this man tells you to get a new chain, get a new chain