OzVMX Forum

Marque Remarks => Yamaha => Topic started by: Rider on January 20, 2017, 06:15:13 pm

Title: YZ 400C piston
Post by: Rider on January 20, 2017, 06:15:13 pm

Not much experience with YZ,s just pulled a unmolested 400C I've had under a tarp for several years out to see if it's worth restoring. The bikes complete with air forks ,side stand , sump guard and original air box. My first dilemma is the bore 85mm as apossed to the original size of 82mm. Are pistons available ? The bore may be usable with a light hone with approx .002-.003" wear. Any advice would be appreciated.  Thanks Terry.

Title: Re: YZ 400C piston
Post by: Tony H on January 20, 2017, 07:27:28 pm

C-D-E  were 85mm. The F had the 82mm.

Title: Re: YZ 400C piston
Post by: ARN on January 20, 2017, 08:02:51 pm

and the c piston is different to d and e

Title: Re: YZ 400C piston
Post by: Rider on January 20, 2017, 08:19:14 pm

Thanks, does that mean it's on standard bore ? The Clymer manual lists 400 models as 82mm which through me .

Title: Re: YZ 400C piston
Post by: motomaniac on January 21, 2017, 02:12:15 pm

Quote from: Rider on January 20, 2017, 08:19:14 pm

Thanks, does that mean it's on standard bore ? The Clymer manual lists 400 models as 82mm which through me .

yes 85m is standard , 82mm was one year,79, only

Title: Re: YZ 400C piston
Post by: TT5 Matt on January 21, 2017, 03:14:07 pm

I've got a set of std rings going cheap if needed

Title: Re: YZ 400C piston
Post by: Rider on January 21, 2017, 08:15:24 pm

Thanks for the responses and the offer of standard rings Matt, but as its on standard bore I will keep my eye out for a first os piston kit to freshen it up while it's apart.
Cheers Terry.