Author Topic: cz 250 mikuni  (Read 928 times)

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Offline gra1961

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cz 250 mikuni
« on: August 07, 2016, 08:21:09 AM »
i have a 73 cz 250 running points and a gmc pipe.has a 32 mikuni at present with 200 main and 30 pilot (cant read needle or needle jet no one at home with eyes at present) runs good from mid range right thru but is pretty doey down low and you have to open the throttle right up to get it to take off out of corners.runs very clean in neutral but under load it lags no coughing or farting just doey.changing clip on needle makes minimal difference.

Offline tony27

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Re: cz 250 mikuni
« Reply #1 on: August 07, 2016, 10:07:50 AM »
32mm could be considered a bit small, all the jetting data I've seen for 250s have at least a #35 pilot in a 34mm or 36mm
Check these links for some different set ups

http://czmadness.net/specs/MikuniSpecs.jpg
http://www.braigasen.com/Mikuni_jetting_chart_two_stroke.htm

Offline Scootern29

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Re: cz 250 mikuni
« Reply #2 on: August 08, 2016, 04:59:03 AM »
A 32mm carb is way small for the 250. Bump it up to a 34MM. I tried the 36mm but the bikes responded better with a 34mm.

Offline rough rider

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Re: cz 250 mikuni
« Reply #3 on: August 16, 2016, 08:39:46 PM »
Where's your timing set ? What's the plug look like ? Think you will find the std Jikov on a a 250 is 32 mm . It is On my enduro I have apart ATM anyway
Is this a problem that has just happened or getting worse or are you new to the bike . The cz's aren't real zippy of the bottom like a jap bike ,they have a big heavy flywheel takes a bit to get them spinning
« Last Edit: August 16, 2016, 09:05:14 PM by rough rider »