Kawi2strokes.com Forum

The 1-3-4-2 firing order Chris described means he fires one cylinder every 90 degrees.

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If it surges, that's normal, upshift.

Hi Don,

Jim is totally correct in how the crank is phased. I don't know what benefits you would gain by altering the phasing to something like 180 degs apart, the two outer cylinders firing together at TDC and then the two inner cylinders firing together at BDC. I think this is how King Kenny's Yamaha TZ worked? That motor worked really well and sounded awesome! If I have got this wrong please correct me.

ALL Yamana and Suzuki 2 stroke 4 cylinder racing engines fire two pistons at the same time, and the other tgwo the same, 180 degrees later, be they inline, V or square 4. Honda used both the same design in their V 4 engines, and, in their inline ones, 1 - 3 - 4 - 2.

Even the NR (Not Ready) 500 and 750 oval piston engines that were 4 stroke, used 180 degree firing pulses, and had two piston sets at TDC at a tgime, one on firing, one on overlap, alternating every full 360 degree cycle.

Laverda used two differfent configurations with their 1,000 cc inline 3 cylinders, first was a 120 degree crank, the later engines in the Jota, 1 and 3 were linked RDC at the same time, 2 was 180 degrees later.

Saab V4 4 stroke car engines were conventional in firing, 1 and 4 were TDC when 2 and 3 were 180 degrees apart at BDC, but, their cranks and blocks were a 110 degree V, like some Ferrari engines are. The Honda NR's were also 110 degree splits.

One had to realize the H2 tranny is pretty much designed off the A1 tranny, 2 and 2 seems a bit much for the little transmission.......

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

This thread rules. Keep it coming!

Has anyone built a twin engine street bike?
(yes I know it would be too heavy and too long to handle well)

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There are only two types of motor sport racing:
Nitro and everything else
(Sometimes referred to as fast and slow)

Yep, look on youtube.

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

Has anyone built a 4 cylinder RD 400?

yes, it s been done, def. int he uk. not as simple as the kawi conversions though. a lot more fussy around the tranny area

There's a shop in portuagal that converts Yamaha V4's(RD-RZ500)into 90 degree firing engines from the stock 180 deg pattern. They call the result "The Screamer". From what I gather, the 90deg set up kills low and mid torque but adds up top. Although theoritacally more functional, what sux about 180deg 4's is that they sound like twins

Listen to this effing thing with its 90 deg cranks and try to disregard the fried clutch.

http://www.youtube.com/watch?v=_Bh7B1Xv ... ure=colike

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1975 H1
1974 S1
Yamaha RZ350
...and a smelly Honda CB350-Four