ESE's works engine tuner

[Flettner]

I might need to change my KB name now that F5 means something different

All the more reason to keep the name F5, I would have thought.

[pete376403]

Did you read the comments on the Klemm site about matching the cases to avoid air leaks. He says the factory didnt machine the cases as a pair and can be quite different at the cylinder base. Wish i had known that sort of thing when I had the F9 - it was great when it was going but had a number of failures (which Laurie Summers wouldn't cover under warranty, something about riding it off road was considered user abuse)

[F5 Dave]

I love the tank, but did you borrow your granddaughters My-first-cellphone to take the pictures?

[TZ350]

I love the tank, but did you borrow your granddaughters My-first-cellphone to take the pictures?

I am not sure what happens, they look alright and properly orientated on my computer but KB posts them in odd ways. I have given up fighting with it.

[TZ350]

Did you read the comments on the Klemm site about matching the cases to avoid air leaks. He says the factory didnt machine the cases as a pair and can be quite different at the cylinder base. Wish i had known that sort of thing when I had the F9

Yes, milled the crankcase cylinder base flat across its surface and square to the main bearings as part of the process. Top of the cylinder is milled 3mm to move the transfers up and the head is grooved for a 2mm Viton "O" ring to serve as a head gasket, 0.8mm squish. Ex opens 81 ATDC, 34mm carb, Inlet opens 155 BTDC and Closes 90 ATDC. Ignition self generating CDI from 12-14 Volts DC and fully programmable.

LOL I worked for Laurie Summers Mt Eden branch sweeping the floors after school. There was a F81M on the show room floor. I loved it. His Mt Eden shop was just over the road from Russels and I also spent time hanging around Whites in Newmarket. Later I worked at the engine re-conditioners down the drive next to Laurie's shop. Crosby and Eric worked at Laurie's Onehunga shop.

[husaberg]

I love the tank, but did you borrow your granddaughters My-first-cellphone to take the pictures?

.......................

[Frits Overmars]

Open heart surgery replacing the standard F5 gear cluster with the new (to me) F81M close ratio cluster.

That piston skirt surprises me. It forces you to either use a narrow, high exhaust port (not so good for low-down power) or to accept a lot of transfer to exhaust short-circuiting, dumping unused fresh mixture into the pipe at such an early stage that it will have moved too far downstream to be shoved back by the exhaust return pulse.
On the other hand, it will lower the EGT, helping low-down power

[TZ350]

That piston skirt surprises me. It forces you to either use a narrow, high exhaust port (not so good for low-down power) or to accept a lot of transfer to exhaust short-circuiting,

The cylinder dictates a single exhaust port. 72% bore width is the most I dare. To get the desired STA I have to open the Ex port of 81 ATDC. The skirt covers the port with 2mm spare each side. I might be missing something, I will have another look. Thanks.

[Frits Overmars]

The cylinder dictates a single exhaust port. 72% bore width is the most I dare. To get the desired STA I have to open the Ex port of 81 ATDC. The skirt covers the port with 2mm spare each side. I might be missing something, I will have another look. Thanks.

If you are forced to use to a single exhaust port, you haven't missed anything. The wider you make any port, the bigger the radii in the corners need to be in order to keep the piston ring alive, and those radii will reduce the port width at the top, where the area counts the most because it's open for the longest time.
A port width of about 70% of the cylinder bore will give you the maximum blowdown angle.area, so that is the optimum port width.

[andreas]

From your pics it looks like it only need some welding outside the exhaust- and Shazam.

[TZ350]

If you are forced to use a single exhaust port, you haven't missed anything. A port width of about 70% of the cylinder bore will give you the maximum blowdown angle.area, so that is the optimum port width.

From your pics it looks like it only needs some welding outside the exhaust- and Shazam.

I have a spare cylinder that needs re boring. After the bike is running and I get bored I was going to do something like Andreas suggests. The plan is to mill a 12mm wide section between two fins parallel to each side of the exhaust duct. Then cap them with a small section of 12mm plate in such a way it leaves room for an axillary exhaust duct underneath. Then at each end of the channel drill through to the cylinder and main Ex duct. Viola, a triple exhaust port.

For me, the main motivation for the triple exhaust port in the spare cylinder is the ability to have the correct STA and reduce the height of the exhaust to get closer to the optimum resonant exhaust timing of 190 - 194 duration. If I get really clever I could have the 12mm cap pieces swing in such a way they can block the axillary ports. A power valve servo could be used to pull them in/out as RPM dictates.

I have to be a little careful as the Pre 72 Post Classic racing class here in New Zealand dictates that the engine must look original on the outside. They must look like they did when actively raced pre 72. Onus of proof is on the rider and I don't have a lot of photos of triple exhaust port F81M's.



Not my bike or Grand Daughter but I would be happy if they both were.

[F5 Dave]

I'd suggest photoshop, but I don't think it's your strong point. Maybe you could ask your granddaughter . But dont use her phone; its probably got a better camera and in this instance, blurry might be an advantage.
Sure Kawasaki had a special Indonesian model with the triple port, as 3 is the national lucky number and 1 is considered evil.

[Flettner]

Did you read the comments on the Klemm site about matching the cases to avoid air leaks. He says the factory didnt machine the cases as a pair and can be quite different at the cylinder base. Wish i had known that sort of thing when I had the F9 - it was great when it was going but had a number of failures (which Laurie Summers wouldn't cover under warranty, something about riding it off road was considered user abuse)

Kawasaki were F$%ckers, their F5 / F9 was nearly a good engine. The rest of the running gear was years out of date.
Silly problems like no squish, three ring heavy piston, clutch too small, a stupid LH / RH crank gear attachment that always eventually undid and poked a hole in the case.
The heavy piston would crack and drop a piece down into the rotary disc valve. Short reach plugs that would eventually strip and blow a plug out. And many more small but annoying issues. Clearly Im still bitter after all these years. ��

Gearbox was good though.

They nearly had something good and just squandered it.
If Kawasaki ring me back now Ive sorted all their problems for them, they can go back into F9 production again. ��

[Flettner]

I dont know why the emojis dont show up, but Im sure you get the picture.

[Flettner]

Now you have me started, on a good evening, planets aligned, paid your dues, the power was outragous. Especially with the original Kawasaki 'hot kit', king of the heap.