74 cz250 Jetting

[ozktm]

Anyone got any ballpark specs on a 38mm mikuni on the 250?

[vmxken]

Hi Adrian - I put this link www.braigasen.com/Mikuni_jetting_chart_two_stroke.htm on our website a little while ago, it should give you some ideas.  That said, most CZ 250s aren't using a 38mm Mikuni, more often a 36mm.

Regards

Ken

[tony27]

I see theres been quite a few settings added since I last saw that list, always amazes me just how much variation there is with similar bikes settings

[jimg1au]

http://160.222.193.110:8080/progress?pages&id=2275435472&sp2&fileName=TWlrdW5pU3BlY3MuanBn&url=aHR0cDovL3d3dy5jem1hZG5lc3MubmV0L3NwZWNzL01pa3VuaVNwZWNzLmpwZw==&referer=aHR0cDovL3d3dy5jem1hZG5lc3MubmV0L3NwZWNzL3NwZWNzLmh0bWw=&foo=4

check this web page

[ozktm]

Yeah i saw that , but i had new 38 sitting there for something else and then just ported the intake out to suit etc.
Runs on what i have, but wanted a closer setup before i got to practice. Currently (from memory) 2.5 slide 6DP1 needle (i have a 6dp5 spare), needle jet Q2, main 330.
Got it idling nice and sounds good while stationary, but didn't wish to take on the law by a lap up the road!

Adrian

[Bamford#69]

Hi,
I don't know of any specs of a 38mm on a CZ250, most 250's run a 34 or 36, If you are following anyones Carb specs make sure its on a "real" bike, not a theoretical guess. the reason the carb jetting specs can vary so much is , make sure you know if  the AIR JET is being used,and what size ,or is it completely removed , which very common on 36 and 38mm VMX Mikunis especially on 360,380, 400 CZ's.
cheers
mkb

[ozktm]

Lots of variables, will just have to plug check, etc.
Thanks for the replies.

[090]

I would like to know the comparison between the cr250m and the cz 250.

[jimg1au]

brad
i have a cr250m and a cz400 and my cr250 is faster on dirttrack than the 400.to be fair the cr250 is built for dirtrack,ported, gem reed valve, 38mm mikuni,runs on methenol, hand made formed pipe.in std form the cz is not as good as a cr250m in the porting department.it is a tip to lift the exh port on the 250 cz and also t top them or wing them as the cr250m is std.while my cz400 was apart i got my engine guy to do just that (you do it to 400s as well) so we shall see how it goes.i also have got a d&h reed valve for a 400 these are preiod made and it is huge pm me your email and i will send you some pics of the reed
jim

[ozktm]

What about handling? To me the CR seems better set for Dirt Track in this regard.
Now the meeting is canceled, i may have time to pull the CR out and set it up to take to the alternate date as well. Then can compare.