Author Topic: 1981 DR400 piston  (Read 2433 times)

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Offline head

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1981 DR400 piston
« on: July 07, 2010, 11:51:18 pm »
Does anyone know of after market pistons to fit 1981 DR400? There does not seem to be much available for this model. I am thinking maybe TT/XT 500 Yamaha as Dr is 88mm bore, and I think TT are 90mm, not sure of piston pin size. Any hot up tips or places to buy parts would be a big help. ???

Offline YUMASTEPSIDE

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Re: 1981 DR400 piston
« Reply #1 on: July 08, 2010, 06:55:40 am »
Talk to Allan at Serco in Brisbane, he told me something about an XT/TT piston for a DR400 once ......I think....maybe    ;D ??? ???

               Roger

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Re: 1981 DR400 piston
« Reply #2 on: July 08, 2010, 09:31:07 am »
I've got a barrel and piston from a 1980 DR400 that's done a genuine 14k. The engine was quiet and blew no smoke if you're interested.

Offline matcho mick

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Re: 1981 DR400 piston
« Reply #3 on: July 08, 2010, 11:59:49 am »
XT's 87mm std,90's big bore,88mm ??,i've a Dr piston ,it's 85mm,(i always thought it was a DR500 piston?),trying to sneak it in a XL350 ;D
work,the curse of the racing class!!
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Offline bazza

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Re: 1981 DR400 piston
« Reply #4 on: July 08, 2010, 03:06:10 pm »
mild port-mild cam - 3 angle valve grind- square mikuni pumper-little more compression and pipe you have a great motor
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oldfart

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Re: 1981 DR400 piston
« Reply #5 on: July 08, 2010, 05:59:15 pm »
Dr 400 std bore size = 88mm ....   pin size = 20mm
It's up to you as far as compression ratio  are concerned ,   10:1     11: 1    12:1   

Yamaha   XT  TT  SR 500    run out to 89mm being 2mm there 2mm O/s  with a 20mm pin

I've gone in a different direction with a Honda set up using the 21mm pin     89mm    >   95mm  ;)