so i have the Athena 125 head sat on my bench for when my bits arrive from MSP.
Before i fit my head onto the engine is it worth getting it ported and polished or would you say there already ported fairly well?
id like to get the most out of the bike when its built i have a limited edition custom made full stainless steel expansion chamber and silencer being made in portugal as we speek but that will arrive in 2 months ish il be getting a carb still got to find one so any tips or links ? and a techtronic CDI
Oh I did not know that...
My method was that I turned out A/F screw about the same as the manual says (28mm Mikuni - 1 and 1/4). Then i went for calm ride using only up to 1/8 turn of the throttle. After 10km I checked spark plug and based on colour of it I further turned the A/F screw inwards. So I did not base on factory setting but on colour of spark plug...
I hope my English is understandable enough...
@Calum I'll take a picture of the head I've got, it's stamped 3MB but it's the one with the ridged, I'll have a look at the book cheers
I planned on skimming the deck down at the end to create slightly higher compression than standard ideally
@Glynn123 yeah but I’ve heard loads over the years about what you have to do to push the bikes without getting it impounded but the problem is practices change from one police branch to another and my specific police impound no matter what they essentially do what they want all of the main criminals and such have the police payed off so there’s no way I’d chance a near 2 grand bike)
the 2003 was easy to derestrict the standard 3rm-20 cdi I actually found very good. Restrictions were the standard exhaust and the reed switch in the back of the speedometer. They came with the powervalve from factory unlike some other years which I can't believe they did fit servos! Back when mine was 125cc it would destroy an 1990 DTR
@sgt-robuck-5 Don't forget the ignitech @Darty rates them.
I used Zeel because it came recommended to me.
I will be buying zeel for my upcoming project.
I've had problems with them, I contacted them and they sorted it out no quibbles.
Peace of mind.
Oh dear, back on topic anyhow....Let us know how you get on with the PV. If it still struggling then it would sound like it's still restricted and needs sorting ASAP! 2003 models were the WORST for restrictions!
2strokes in general is jetted plenty rich, to make sure they dont seize.
I run my 94 R with snorkel removed, and the airbox opened slightly more.
Stock mainjet, and half a notch leaner on the needle. The mainjet is still plenty rich.
Stock header, and aftermarked end can, otherwise stock.
You shouldn't be polishing either really,
but here is a used MITAKA vs a New WOSSNER to illustrate. Carbon does help to a point. The Wossner is a CNC finish, but if your hunting power there wont be any difference.
Problem with forged is the difference in thermal expansion to a cast alloy. MITAKA is a good choice for the DT.
Smooth yes, but a rough surface lends itself to optimising fuel atomisation, that is more important.