Sooty small-ends

Classic Bike (UK) - - WORKSHOP RICK’S FIXES -

Keith Livingstone stripped his 1974 Tri­umph T120 to check up on an an­noy­ing rat­tle, but af­ter heat­ing the bot­tom end in the oven to part the cases he found oil had baked to form car­bon in the small-ends.

“I re­alise I should have cleaned all the old oil off be­fore put­ting the bot­tom end in the oven, but how can I re­move it?”

I’d think the car­bon was al­ready there, Keith. It can build up when the bushes are worn, be­cause the pin is no longer mak­ing a full con­tact. If it is just baked on from heat­ing, prob­a­bly the best way to re­move it would be with a twisted ‘rope’ of wire wool or maybe a bit of fine emery pa­per wrapped around a wooden dowel – split the dowel down the mid­dle and insert a folded strip of emery to make a lap­ping tool; go easy and use a bit of light oil. If you do de­cide to re­place the small-ends, it’s best to press or pull them into the (hot) con­rods us­ing a shoul­dered tool made up to fit.

Ide­ally, you want a tube big enough to press the old bush into on one side and a stepped man­drel the other side to sup­port the bush as it goes in. The tight fit should mean that, once fit­ted, the bush will need to be reamed or honed to size.

LEFT: Car­bon on your small-end sug­gests wear.

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.