OzVMX Forum

Clubroom => Tech Talk => Topic started by: 35elsinore on September 20, 2011, 01:47:46 am

Title: mikuni jetting for 74 cr250
Post by: 35elsinore on September 20, 2011, 01:47:46 am

Wondering if anyone has any jetting specs for 38mm VM mikuni  for a 74 cr250m
Thanks for any help

Title: Re: mikuni jetting for 74 cr250
Post by: Freakshow on September 20, 2011, 10:46:56 am

38mm sounds a little big, i would have though a 36mm wouls have been more than enough.  guessing i would say start at #270 main and #50 pilot, the rest would be plug chops.

Title: Re: mikuni jetting for 74 cr250
Post by: 35elsinore on September 20, 2011, 08:01:21 pm

Fire breathing hondas love a big carby.

Title: Re: mikuni jetting for 74 cr250
Post by: Freakshow on September 20, 2011, 08:05:18 pm

really..... then why do they sell them with Keheins

Title: Re: mikuni jetting for 74 cr250
Post by: Freakshow on September 20, 2011, 08:06:15 pm

Are you putting it on meth ? even then its seems too big for a piston port.

Title: Re: mikuni jetting for 74 cr250
Post by: jimg1au on September 20, 2011, 08:18:37 pm

i have a 38mm on my methenol cr250 elsinore and a 38mm on my petrol (don jones) cr250 elsinore
both have reed valves.
i mate of mine also has a 38mm on his cr250 elsinore and his is quick he runs elf fuel
cheers
jim

Title: Re: mikuni jetting for 74 cr250
Post by: GD66 on September 20, 2011, 08:31:48 pm

Braigasen chart has info for a '73 CR250 with a 38mm Mik...

http://www.braigasen.com/Mikuni_jetting_chart_two_stroke.htm

Should haul ass when you get it cleared up, buddy !  ;)

Regards GD

Title: Re: mikuni jetting for 74 cr250
Post by: 35elsinore on September 21, 2011, 10:03:59 pm

It currently runs a keihin 38mm but after many hours I cant quite get it just right. After fitting a new 34mm mik to my cr125 [taking off the 34mm keihin] it cleaned low and mid range up sweet. So now I love mikunis and thought the 250 needs a birthday to. Hoping the same could be achieved on the 250. Only running 98 ron on both bikes.