yamaha conrod questions

[tavspeed]

hi all,got a rb crank with a knackered big end,so going to have a go at pressing pin out ,trueing back up and tig welding the pin.
the crank measures 40.64mm over the webs and conrod measures 15mm wide at big end, so looking at the rd/dt175 mx rod which is 16mm wide at the big end,and will run with out shims and 4 thou clearance each side of the eye,so looking at around 41.6mm wide.
would this be ok with a extra mag flange gasket or would i have to machine the rod,or crank webs,or is there a better conrod to use,i see AF have a yamaha rod kit on there web site,but don't know what model it is from,cheers all

[Warkton Tornado No.1]

hi all,got a rb crank with a knackered big end,so going to have a go at pressing pin out ,trueing back up and tig welding the pin.
the crank measures 40.64mm over the webs and conrod measures 15mm wide at big end, so looking at the rd/dt175 mx rod which is 16mm wide at the big end,and will run with out shims and 4 thou clearance each side of the eye,so looking at around 41.6mm wide.
would this be ok with a extra mag flange gasket or would i have to machine the rod,or crank webs,or is there a better conrod to use,i see AF have a yamaha rod kit on there web site,but don't know what model it is from,cheers all

I'm presuming the centres are 110 mm, in which case look @ the KE175D as it is too only 15 mm wide. Dependent upon supplier, you may want to request a silver plated big end cage.

(Obviously, the big end pins from bike conrod kits are often too long, but you must know that & be capable of shortening to suit)

[tavspeed]

cheers,grampian motors have mitaka ke175d conrods in stock and want £20 to turn the pin down or af have pins at £12,so will have a measure up when i split crank,but the ke rod is looking favourite,cheers

[Warkton Tornado No.1]

cheers,grampian motors have mitaka ke175d conrods in stock and want £20 to turn the pin down or af have pins at £12,so will have a measure up when i split crank,but the ke rod is looking favourite,cheers

You are welcome

The pins are a doddle to shorten, especially if you can rough grind to near length then finish with a die grinder/Dremel/Makita type file whilst spinning them in a lathe or even a pillar drill.

However, if you are thinking of buying another pin, then consider an eccentric one (shop around!) to gain stroke & gain a bit of blowdown