ESE's works engine tuner

[F5 Dave]

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Kawasaki F81M Post Classic Racer Build.

Now that we have some parts to play with, the ideas can flow.

Attachment 343549

The first step is to improve the transfers. The Suzuki has a much better looking duct shape than the Kawasaki.

Attachment 343548

If I fitted the piston port Suzuki cylinder to the rotary valve Kawasaki. I could have two inlets and arrange one of them as a 24/7 when its up on the pipe. Open all hours, it's kinda crazy, but a very tempting idea..... . There have been racing single cylinder twin carburetor specials made before.

I am not sure if fitting a Suzuki cylinder to a Kawasaki will be regarded as an after market conversion or a tuning modification. Back in the day I was running Yamaha cylinders on my TR250 Suzuki so mix and match has certainly been done before.

These are the class rules:-

Attachment 343553

And that's why rules are so hard to write.
One would have to read that paragraph wrt intake system, otherwise you couldn't put clipon bars on. But that while giving a freer hand on cylinder would make a target on inlet. Two carb bikes never seem to offer any real advantages. I'd be blocking inlet and Devon the area into a C port. I did just that with my MB when I full cased it.

[Brett S]

You saw it here on Kiwi Biker first, mk2 TPI.
This arrangement allows for better control and better homogenization. B port injectors first at low speed, then A and B port injectors once up on the pipe. B port TPI will supply fuel to the A ports at longer injector on times but not so controlled, not like this.
Anyway if I were you I'd inject like this.

Looks good Neil.
Can you explain what the plunger looking part is sticking out the end of the fuel rail?
Will the fuel system be dead headed or have a pressure reg with return line?
Is it just the picture or is that radiator very thick?

[husaberg]

.
Kawasaki F81M Post Classic Racer Build.

Now that we have some parts to play with, the ideas can flow.

Attachment 343549

The first step is to improve the transfers. The Suzuki has a much better looking duct shape than the Kawasaki.

Attachment 343548

If I fitted the piston port Suzuki cylinder to the rotary valve Kawasaki. I could have two inlets and arrange one of them as a 24/7 when its up on the pipe. Open all hours, it's kinda crazy, but a very tempting idea..... . There have been racing single cylinder twin carburetor specials made before.

I am not sure if fitting a Suzuki cylinder to a Kawasaki will be regarded as an after market conversion or a tuning modification. Back in the day I was running Yamaha cylinders on my TR250 Suzuki so mix and match has certainly been done before.

These are the class rules:-

Attachment 343553

https://www.facebook.com/12051123795...5923856084764/

Kawasaki F5 / F8 / F9 Close Ratio 5th gear
The stock 5 speed transmission of the Kawasaki F5/F8/F9 is actually a close ratio 4 speed transmission with a very tall and distant 5th gear ratio. In the past, the best close ratio option was to install the F81M gearbox. As time has gone on, these F81M gearboxes have become very rare (and expensive). To attend to this problem, we have embarked on “fixing” the 5th gear issue of the stock gearbox…. And that fix is not complex.
The H1 triple 5th gear-set installs easily into the Bighorn gearbox, and it offers a ratio that turns the stock Bighorn gearbox into a “close-ratio” box. The problem is that the stock Bighorn 1st gear (driven-shaft) that engages this H1 5th gear has the wrong shift-dog pattern.
We are in the process of manufacturing a custom batch of the Bighorn 1st gear that will allow the use of the H1 5th gear. The ratios (compared to the F81M gearbox) are shown below.
GEAR F9-H1-5th F81m
1st 2.45 2.45
2nd 1.71 1.60
3rd 1.17 1.26
4th .90 1.09
5th .81 .95
As the chart shows, the 4th and 5th ratios of the H1 modified F9 box are “very” close to one another….. but that is ideal for high geared pavement engine arrangement.
The H1 5th gear set are all the same (among different years), and readily available worldwide. We will be offering the modified 1st driven-shaft gear to mesh the H1 5th gearset for $219. each (plus freight). There are a limited number available, so a $100 deposit will secure the gear until delivery around May 1st. If you change your mind after deposit, we will gladly refund you. At this time (3/13/18) only 4 are still available.

[Flettner]

Normal pressure system with return to tank, relief valve is removed in the picture. Valve is special in that the exhaust pressure changes it. Not finished yet.
Radiator is twin core, its a single radiator, othet side is now air cleaner.

[husaberg]

There is already a bend in the header.
Put a bend at the end of the header/start of diffuser join , then one at the end of the diffuser/start of the mid section.
No extra cuts or welds - easy.
Oval changes the area and thus the pipes efficiency - bad idea.

[TZ350]

Pinky makes noise.......

[Brett S]

Normal pressure system with return to tank, relief valve is removed in the picture. Valve is special in that the exhaust pressure changes it. Not finished yet.
Radiator is twin core, its a single radiator, othet side is now air cleaner.

Ah on closer inspection i see now that is just a button head capscrew in the end.. I thought it was a spring over a plunger..

So its an adjustable fuel pressure reg like a turbo 4 stroke car's fuel pressure regulator referenced to manifold vacuum and boost.

[katinas]

I could do that, but i want it to be easy to build new pipes, easiest pipes must be a straight one
If routing it a bit to the side i will get into new problems.

I can lift the pipe about 20mm.
and a smaller rear tire would also give me about 10-15mm
Then i think i´m home free.
I havent made the pipe oval yet

Maybe its not good example, but to find place with the "straight" type swing arm, on 1987 NSR 500, Honda used the most flattened pipes on Gp racing scene. Power 163hp 12000 rpm together with normal shape upper pipes.
Add photo Elf bike with that 1987 NSR 500 engine and exhaust

[husaberg]

Of course, its not good example, but to find place with the "straight" type swing arm, on NSR 500, Honda used the most flattened pipes on Gp racing scene. Power 163hp 12000 rpm with two normal shape upper pipes.

I see your Honda GP500 and raise you F750 Plus AMA dirt track

i have better photos in my TZ album but i are not allowed to access them at the moment.
BTW if anyone is interested in the albums you better take a look as i willl be deleting them off the site in a months time.

[katinas]

Nice pictures Husa.
For 1988 season Honda used round shape lower exhaust, but with cuts for rear tire and right side cut on swing arm for pipe. 162.8hp 12500 rpm.
Add Yamaha YZR 500 1985 left hand side exhaust with cut for chain and swing arm

[Muciek]

I was trying to find them few days ago but it does say that I don't have the access(using links from 1000 page). And the direct link from user profile to galleries is gone. Are they gone already ?

[husaberg]

I was trying to find them few days ago but it does say that I don't have the access(using links from 1000 page). And the direct link from user profile to galleries is gone. Are they gone already ?

No idea i are in the naughty corner atm so i cant see any of my attachments.
But if they are not gone already they will be deleted soon as iam able. Sme as there is over 10,000 pictures.
But as it seems the site moderators have decided they would rather have content from internet trolls rather than motorcycle stuff.

[Zrt1200]

Hello fellow 2 stroke tuners. My name is Al and I am a retired CNC Machinist with his own work shop at home. I have modified a lot of 2 strokes over the last 30 years mostly for drag race snowmobiles with a CVT transmission but dirt bikes and 4 wheeler's as well. I currently use TSR software and I have been looking into Engine mod2 as of late. I use to Drag race snowmobiles for years but once I got married and had kids the garage money went for toys so the kids could go riding and my racing was on hold. Our youngest is now 21 years old and out of the house so I am thinking about building a new drag race snowmobile for my self. I have been a member here for a few weeks now quietly reading in the background and using the search function. I have read all 5 chapters on Pit-lane biz on the Aprilia as I am trying to get my self up to speed for a new build. I am also on facebook and have read and posted in 2 Stroke research & development. Frits Overmars, Jan Thiel, & Wayne Wright are great minds and I would like to thank you gentleman for your post's and answering our question as we all are learning from you guys.

[Frits Overmars]

Hi Al, it's good to have you here, where we have all the facilities that we don't have on Farcebook, like proper chronology, and quote and search functions that really work .

[AndreasL]

No idea i are in the naughty corner atm so i cant see any of my attachments.
But if they are not gone already they will be deleted soon as iam able. Sme as there is over 10,000 pictures.
But as it seems the site moderators have decided they would rather have content from internet trolls rather than motorcycle stuff.

NO!!! Sad to hear that. Your pictures are a real treasure and would be a great loss not to have here to go through.

Wish there was something we could do to have “someone in charge” change their mind...or something.
Totally understand your decision though...without knowing the background.