The 50

[Juho_]

Still same main jet and some ignition fiddling and 13.7hp still peak @ 11500.
...
Anyway this thing revs to 14k happy. and makes 13.7 at 11/ 5. Still no proper cylinder head design and pipe is shithouse. A good start for a rush job.

That's a great peak hp number, if measured / calculated power from gearbox or back wheel.

The Athena 50cc (old model, with T -exhaust port, same as you have), has "ok" transfer ducts as stock form.
I know two racing engines, that have the same cylinder with only some small modifications and combustion chamber machined for larger volume (to get the engine rev and actually make some power).
They had around 15hp@~11.8-12krpm from back wheel at Fuchs dyno, at their best jetting and ignition timing.
Both with PWK28, but with different inner rotor ignition systems and the other one with an aftermarket pipe (SCR RL50 ; other bike had a DIY pipe, but still made approx. same power at around same rpm's).

Do you have any molds of the transfer ducts..? Just curious.
I didn't have a chance to make vinamold molds from the transfer ducts, when I had Athena 50cc cylinder, that I ported for a customer.

[richban]

That's a great peak hp number, if measured / calculated power from gearbox or back wheel.

The Athena 50cc (old model, with T -exhaust port, same as you have), has "ok" transfer ducts as stock form.
I know two racing engines, that have the same cylinder with only some small modifications and combustion chamber machined for larger volume (to get the engine rev and actually make some power).
They had around 15hp@~11.8-12krpm from back wheel at Fuchs dyno, at their best jetting and ignition timing.
Both with PWK28, but with different inner rotor ignition systems and the other one with an aftermarket pipe (SCR RL50 ; other bike had a DIY pipe, but still made approx. same power at around same rpm's).

Do you have any molds of the transfer ducts..? Just curious.
I didn't have a chance to make vinamold molds from the transfer ducts, when I had Athena 50cc cylinder, that I ported for a customer.

Hi Juho.


That was at the back wheel. I am making a new FOS pipe this week so hopefully the engine will carry on making power up over 13k. It has no trouble reving. It just needs the pipe to make it all happen. No mould's sorry. This is very rush rush. After this race meeting I will pull it apart and to model in engmod.

Cheers Rich.

[mr bucketracer]

Speaking of which, I have a bit of avgas left from the nationals this weekend that someone is welcome to. Also about 8 litres mixed 30:1 with elf 976 too.

you may want the non mixed stuff (-;

[richban]

Many hands make light work. After 4 hours of good times and smack talk. Andrew and I produced this little gem. All hand rolled and a little rush rush. But man does it sound amazing. All going well, this will fill the hole from 12 to 14 with big fat chunks of horsepower. We will see.

[mr bucketracer]

Many hands make light work. After 4 hours of good times and smack talk. Andrew and I produced this little gem. All hand rolled and a little rush rush. But man does it sound amazing. All going well, this will fill the hole from 12 to 14 with big fat chunks of horsepower. We will see.

nice work rich

[cotswold]

Rich that 50 is looking scary good in such a short period of time, hate to think how many horses you will pull out of it given a year..........nz's first 20bhp 50??

Coolants, do any of you boys use one and if so which one. I got sold a bottle of Motocool expert by Motul as being track safe but after a bit of reading I am now unsure.
Waterwetter is coming tomorrow which is track safe but it's not what I was originally after.

[richban]

Rich that 50 is looking scary good in such a short period of time, hate to think how many horses you will pull out of it given a year..........nz's first 20bhp 50??

Coolants, do any of you boys use one and if so which one. I got sold a bottle of Motocool expert by Motul as being track safe but after a bit of reading I am now unsure.
Waterwetter is coming tomorrow which is track safe but it's not what I was originally after.

Water wetter works well. Also Motul Mocool is great. blue label concentrate.

Not sure about hp on the 50. I would be happy if I get in running nice. On that note I really need a rear RS sprocket above 48 tooth. If anyone has one they would like to sell or lend me. Please bring to GP.

[F5 Dave]

Penrite 10 tenths is tracksafe
There are two types of glycol apparently.

[husaberg]

Penrite 10 tenths is tracksafe
There are two types of glycol apparently.

ethylene and propylene from memory.
The poly stuff is dearer and sold as fashionable racing coolant for MX4 stroke race bikes.
http://www.engineice.com/

Propylene Glycol you can buy from a vets.
Its food grade 100 percetnt pure as its used treat ketosis in Cattle and sleepy sickness in Sheep (metabolic disorders that basically need a sugar hit)
http://www.revivalanimal.com/Propylene-Glycol.html

[cotswold]

well it made me sad,
my nice new head has been removed and replaced by the piece of shit original one due to a leaking fitting that i have no time to replace. The shock has a softer spring so at least that seems to be all good.
Next year

[TZ350]

Can you repair the fitting, glue it in place with 5min Araldite.

[husaberg]

Can you repair the fitting, glue it in place with 5min Araldite.

Paging F5dave............

Note shouldn't you be suggesting ballazona or whatever it was?

[F5 Dave]

Not me. Be Devcon or JBweld.

[husaberg]

Not me. Be Devcon or JBweld.

Yeah, but I knew you would know just what to use

[F5 Dave]

Water wetter works well. Also Motul Mocool is great. blue label concentrate.

Not sure about hp on the 50. I would be happy if I get in running nice. On that note I really need a rear RS sprocket above 48 tooth. If anyone has one they would like to sell or lend me. Please bring to GP.

Sorry man I have a 45 only. My other 48-51 range runs on a carrier that's on the 50 currently.