Kawi2strokes.com Forum

Then this portwork is done. 260 mains, P5, 6DH2 mid position on this last dynorun. No air filters. Warm oil, warm crank, "half warm" cylinders.

I am happy with the reseult. Especially peak power at quite low 8000 rpm. Don't need a whole lot of rpm to get the power as long as the portwork is ok, with ok torque.

Powerband starts at quite low 5300 rpm. 34 HP. No significant flat spot in mid range. Should be very streetable, and can give full throttle from 3000-3200 rpm.

90 Nm torque at about 7200 rpm. Satisfied, as I don't exactly get any help from the SpecII pipes. Overrevv is very good, she even peaks up a bit around 8600 rpm. That means, when changing gear at 9000 rpm, you actuallly hits the very sweet spot at around 8000 and have 95rwhp at once. Don't know why this happened though, must be a residual pulse. My estimate if jollymoto was used for this set-up..........at least more then 100 rwhp.

Not a perfect dyno sheet, but ok in my opinion. Others may say I have a lot learning left, and the one with problems. Should I care?

Thank you all for following this thread. More projects like this will follow, as there are some reeded and ported cylinders around here as well that needs to be looked into.

Joe: Your specII pipes are not the reason behind your flat spot as you can see from this quite heavily ported H2 dyno sheet, and definitely not at 5252 rpm (stock ignition by the way) but I guess that will be questioned later on.

Below is the final dyno sheet for this project: (90 Nm is 66,38 ft/lbs)




Below is a sound clip of my own H2, modified Jollymoto. I like the sound of my first H2 project. It has as best 124 rwhp. Estimated power at video, around 115. Hits the rev limiter in third at 9200 rpm (about 100 mph) as you can hear. Gearing is 14/47, that is about 17% heavier gearing then a stock 15/45 H1.

Turn up the volume

(sound like a 100 years old tractor on idle though, only 800-900 rpm.



Jørgen

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

Good stuff Jorgen
I hope you keep it coming on the other projects.

One thing to note on my project I can accelerate from 2500 right thru to redline with no hesitation, it goes right through the RPM range and the "problem" area like it does not exist.
It is only a problem when I try to accelerate from right around 5000 rpm in top gear, then it hits a wall.
If I down shift to get the rpm up, it flat out flys. If I start lower in the rpm range it pulls cleanly through and hits very hard at 6000 rpm and the acceleration gets crazy good.

I am not used to any thing like a power band at all...in comparison to a 2 stroke!!.... My main ride for nearly 30 yrs has been a 1260 Gs Suzuki that can accelerate in top gear from ANY rpm and stretch your arms doing it.

I have put many hours of thought and study into these dyno charts, yours , Johns, Nevs, and I think I may need to adjust my thinking to more of a 2 stroke mentality or I may never get my bike jetted correctly. I think I am trying to jet out the normal 2 stroke way!!

Also Interesting you went to a 6DH2 needle, are you finding the A/F sensor useful??

I did buy a set of 5FP-17 needles to try next spring on Nevs suggestion...we wills see, Im hoping for good results.

Yeah. Mr Lush also has a lot learning left, he could not even find the for emotional purposes, like I did

By the way Neville: Happy National Day, your Australia is really a great country is many ways!

..j.

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

You'll get there Joe, eventually. It took some time for me as well, and I still struggle getting my strokers going like they are supposed to, even having all my good "tools".

Patience is the key...... Remember what Phil said: His carbs went on and off like 20 times or even more, when jetting his H2.

..j.

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

Great work Jorgen, how do the spec 2 pipes compare with other "old school" pipes like denco, TNT etc?

That is a great result, with nearly 30 hp more and the torque at 5000rpm is pretty much the same, no loss of low end. The customer will love you Jorgen. The AF gauge will greatly shorten your jetting time Joe( Demus?). One can actually measure what to change at what throttle area. If one knows me personally I have been accused of being almost emotionless, if I am honest this is probably quite accurate . Especially at the track. My charming wife has tried to improve me in this area. Beer improves me in that area. I had a good Australia day. Regards Nev.

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I am just a man working in a tin shed.

Nev is a "warm and fuzzy" bloke, if ever there was one...........!!

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

Ha, yeah I am a caring understanding nineties type.

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I am just a man working in a tin shed.

Ya its Joe, "Demus" means incomprehensible, which pretty much describes how I got the bike and how much I understood about it. I never planned on posting at all, I thought I would gather some info and put the bike together, it has now taken on a life of its own and I find myself "talking to friends I don't even know, still incomprehensible!

A lot of good info has been posted and all at a good time for me as I learn about the old 2 strokes!

My wife and beer both cheer me up, but I am not emotionless according to her!