Kawi2strokes.com Forum

If during your trip you will go in Paris I would like seeing you and your other half.
Could even have a small flat for free depended of the dates with a 350 S2A to move better than a big K triple when you discover Paris and around driving
And end of may Coupes Moto Legende in Dijon track; we will have a H2 to go in from Paris to Dijon(around 360 kilometers on small twisty roads) for you and other half and everything to camp, eating and so on.
end of june or first week of july Northern rally, we will have a H2 also if you want come with us from Paris to Uk and back (650 kilometers from Paris to Nottingham UK)
Idem est the second or third week end of september for the Southern rally (350 kilometers from Paris to Maidstone UK)

Thank you, J.P. - the (straight-cut) gears in my brain are turning around!!

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"One day, your life will flash before your eyes. Make sure it's worth watching." : anon.

New pistons are on they way here But i need some advise about inlet timing! Here's a guideline anyway:

Rpm Inlet duration (°)
7,000 150-155
8,000 155-160
9,500 165-170
11,000 185-190
12,000 195-200

Looking at this and with my pretty heavy mod. barrels in mind i prob. should aim for 160deg.?

Engine spec: Ex.198deg. M.transfer: 127deg. sub.transfer:129deg. Carb's Mikuni 40 or Lectron 44
pipes are aprox. 1100mm long (from piston to start of stinger) with a 115mm. belly.

The more duration the more loss at a the lower RPM range. I would start out with 1mm raise on the skirt and see how you like it. It will only be the cost of some gaskets if you need more.

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

1mm. will get me about 156deg. And your right, i can always raise more if not good and it woulden't even cost me gaskets
since i'm going for copper basegaskets this time

Thanks John!

First thing you do, is putting those new pistons in as they are. I strongly recommend you trying out this new set-up without increasing inlet duration at all to keep some low end power.

And when doing this, you will have a guide line how your motor woeks BEFORE you do none reversable modifications. You cant raise your cylinders either, because you are very close to dragrace spec at your exhaust duration.
You have a couple or so degrees left for your transfers, but thats all.
By the way: If you raise your transfers, you will hurt midrange, the powerband will start later, but ypu will probably gain a little peak power (IF sufficient blow down, which it seems you have if ex ports are widened and squared as well)

And with lectron 44, good 115mm diameter pipes (they are 7mm wider than my Jollymotoes) and durations like you have, more than 130 rwhp is within reach IF everything is done correctly and the pipes works.

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72 H2, 72 H1B, 74 H2, 74 H2 Cafê Racer, 71 F8 Bison

Ok Jorgen you win Will save me some grinding to Never messured blowdown but ports are wide and square alright.. And 130 rwhp would be nice but i would settle with 120 with better midrange..

Thanks Jorgen!

1 to 2mm shows very little effect to low rpm power, but it's worth the try to just slip in the pistons.

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

Cool,

Then leave your inlet duration as is for now, and be careful when modifying your inlet tunnel and window.

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72 H2, 72 H1B, 74 H2, 74 H2 Cafê Racer, 71 F8 Bison

With my hot cylinders on the shelf waiting for new pistons i've been riding around with a stock 72-73 topend witch have 3mm.cutaway pistons, stock pipes and bored out vm 34's (35,5mm.) Really nice setup, lot's of torque! Desided to try my pipes on this setup today just to see how they would perform vs. stock pipes. And they performed really good! Lowend grunt is still there with a healthy midrange Topend isn't that impressive with stock porting.. But i know from running my ported cyl. they rev out good and topend is strong. Should be intresting to try the other topend soon..