dps650rider
XS650 Addict
For the record my bike is rephased. I for one am very happy with the difference it has made in vibration reduction.
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Rephased 1979 xs650
- Thread starter Tony Jara
- Start date
For the record my bike is rephased. I for one am very happy with the difference it has made in vibration reduction.
Gary if you're thinking of rephasing use the heaviest rod and piston to bring the balance factor
closer to 52 %. Wiseco 750 pistons would be an excellent choice with XS 650 pins.
650rider has both versions of the XS.
Hello Jack ,no not planning just like to hear the different thing they did as well as where it changes. See if we can find a common denominator.
Jack also I am wonder if anyone does balance them or just true them.
The Aussies to my knowledge take the time to balance,at least the racers do. Google Aussie XS650 club racer,click it and enjoy. The crank assembly is a work of art with a touch of physics for asphalt racing. For the most part truing it up is standard.
Gary here's what a hot long rod rephase sounds like, it' just plan nasty
Just checked out Geoff shop, looks like he has a good selection of early xs's here is the link ..http://www.xs650.org.au/Geoff's XS/geoffs XS.htm
Thanks for the correction......................I have edited my post to reflect that.
dps650rider
XS650 Addict
I bought the bike new and did the rephase in 2008 during a rebuilt that included new crank bearings, rods, overbore to 700cc, Megacycle cam, etc, etc. The biggest improvement is when it is over 5000 RPM where the difference is dramatic.
BTW, I think Jack is spot on with the recommendation to set the balance factor to around 52%. I studied this extensively and concluded that for a 277 the ideal factor was 53%. However I did not rebalance mine and still wish I did. When I built my engine I used the 10:1 JE pistons. After riding it a season and fighting with detonation I took it apart and milled the pistons to about 9:1 removing some weight (still heavier than stock pistons). After this I definitely noticed a bit more vibration, still quite a bit better than stock though. Ideally the best solution would be to keep the reciprocating mass low and modify the crank to set the balance factor to around 53%.
I always wonder if this is the reason many people are not happy with a rephase, if it was done with stock pistons without rebalancing there may be little or no improvement.
Gary, who do you use for balancing?
