Which crankshaft?

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Nobars
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Which crankshaft?

#1 Post by Nobars » Thu Feb 09, 2017 8:06 pm

I have had an RZ basket case for a while now. When I bought it the cylinders were off, and the crank is rusted so I need a new crank(rebuild is not possible).

I don't believe I want to do a stroker, but it does have spec2 pipes, big carbs, ported and aftermarket reeds/cages.

I have built a lot of racing engines, but this will be the first 2 stroke in a real long time. (Machinist/cnc programmer).

What crank is safe/reliable? I'm sure to get many responses. I need to get the crank and get this project moving forward.

evan_calgary
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Re: Which crankshaft?

#2 Post by evan_calgary » Thu Feb 09, 2017 11:51 pm

Anything banshee will work....lots of options.

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Questo vecchio rz
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Re: Which crankshaft?

#3 Post by Questo vecchio rz » Fri Feb 10, 2017 2:19 am

Try contacting Tony Doukas of TDR reed fame. Hes a member here, goes by TDR_50. He can advise you or set you up w whatever you need, or browse his website and decide for yourself. http://www.bansheesuperstore.com/" onclick="window.open(this.href);return false;


I'm assuming this will be a street ridden RZ, and that your existing port work probably a traditional mild street port if so.. its pretty basic so no need to much beyond a stock spec crank! If its a period spec roadrace port..w large carbs, your going to sacrifice lowend performance.
A Spec 2 or equivilant stage 1-2 street/ fast road with 30mm carbs either round or flat slides usually retains good street power with plenty of low & midrange power on tap.

Its not necessary to get all hung up on HD bearings and there is absolutley no need for a billet crank, you can get by with virtually any of the well known aftermarket cranks either welded or not .
, and either way you can beat on it it for years at any rpm without any worries whatsoever.

Of course, any additional modifications past stock are totally up to you but for a fun reliable 55-65 h.p. street RZ your "money" with just a OEM spec build, if your going to do trackdays etc at sustained high RPM...then consider perhaps making it stronger.

My advice, again if its intended for a fun reliable streetbike is K.I.S.S. on most of your build. No real need for billet cranks, clutch baskets, billet & O-ringed heads, upgraded programmable ignitions, PWK carb conversions etc..no need at all, what you already have makes for a real fun bike, If Gary @ Spec 2 did the original work, thats a good thing. Garys builds & modifications have always been pretty solid performers & his pipes have always been pretty good for strong midrange power.
Of course you can optimize any & all of it for further gains, thats up to you & perfectly understandable but obviouslly increases your costs substantialliy. Just a. complete modified engine rebuild alone can easily approach or exceed 4 thousand US dollars.
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JonW
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Re: Which crankshaft?

#4 Post by JonW » Fri Feb 10, 2017 8:26 am

OEM. period. its just over $400. search this site, plenty of info etc.
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Nobars
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Re: Which crankshaft?

#5 Post by Nobars » Mon Feb 13, 2017 12:30 am

Thanks guys.

I have more questions, and some photos(they are too big). I finally found some markings on the cylinders and was wondering if anyone could identify the porter.

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