WR400 connecting rod
Posted December 16, 2004 - 05:14 AM
when it's time to replace my only option is press on a 426 rod to match, cant get replacement pistons anymore as far as I know at least
Posted December 16, 2004 - 10:11 AM
cant get replacement pistons anymore as far as I know at least
They only made a handfull of those pistons. They were about 12% heavier than the OEM piston and accelerated rod breakage when guys installed them in engines with a lot of hours on them.
The 426 rod is just better all the way around.
Posted December 16, 2004 - 12:16 PM
I've got so many hours on the bike, last year it was rode 8 hours a day 2 days a week
Posted December 17, 2004 - 08:50 AM
Are they heavier due to the extra 4mm diameter? or more material somewhere else?
They used a different forging process with those pistons than they do on the new YZF250 big bore pistons. The YZF250 2mm over pistons are actually lighter than stock by about a gram (I don't remember the exact amount off the top of my head).
So in answer to your question it's probably a combination of the process and the size of the piston.