Autisa 175cc jetting

[sgfo]

Hi 

I have a autisa cylinder with wiseco blaster piston and mikuni vm 28.

Do anyone have a baseline jetting to start with.


best regards SGF Sweden

[neil]

I'd start with a large main jet so it runs rich to start with then work my way down until it runs crisp doing a plug chop as it explains on here in the technical section. Hope this makes sense.

[sgfo]

Thanks.

That was the plan to work me down to right color on the plug.

[rdv]

Hi,

Would have thought to start with the jetting of a DT 175MX mikuni carb
and adjust the settings,jets, from there .

[rdv]

Hows it running since you last posted about the problem?
Also,what Exhaust pipe are you using,state of tune?
Things to take into consideration is your area above sea level,
weather, and oils,fuel you use.
As most people know,its these factors on how an engine works to its best.
Best to get it set up properly on a Dyno Tune for the purpose you want it for.
Hope this helps.

Rob

[sgfo]

Hi
I have a 28mm new mikuni. i have to take 1.2mm of the base of cylinder. i use a 66.5mm blaster piston made by wiseco. The wössner piston was to Heavy i Think. The top of the cylinder is also being shawed off.
Cylinder head have to be modyfied to. The right squish have to be made.

Best regards SGF Sweden

[yamyzee]

Hi!newbie here with 30 years experience of messing/tuning/ruining these engines.throw the 28mm away and get a 36mm mikuni off a yam it175.drop the main down from a 360 to a 320 and run on premix.im not sure if the oil pump can flow enough,never took the chance...the carbs are the major restriction on these.you wont be able to drill enough holes in a standard airbox to flow enough air to feed it and the standard carb to airbox rubber is to small so an s+b,k+n type cone filter or no filter at all is the way to go.a blaster piston isnt the best as the ring pegs are a bit close to the rear boost port on the autisa and if you dont remove the rear tab from the blaster piston the little end life is dismal.i have seen people try everything to tune these big bore kits with no luck....bigger carb and they fly!!!!!!oh yeah an mx 90 degree quick action throttle is needed,trying to wind open a 36mm with a standard throttle is horrible....hope this helps!

[yamyzee]

Or alternatively......find a carb from an old air cooled rd350 twin (1975?),the side with the choke lever on,block off the feed to the other carb and it should be jetted about bang on as it is for the autisa kit.from memory its a 29.5mm bore and you can retain the standard cable/oil feed pipes.i used to run one on an autisa kit with no air filter element?boyessen reeds and a full fresco pipe on a dt125lc 10v.worked great and i used to leave my mate for dead on his xt600 around twisty backroads lol :-)

[sgfo]

Thanks for the inputs.