jetting

[sparky]

i have fitted some aktive reeds from lt and iv also custom fitted a full fmf system from a 2004 cr 250
what jets should i be running
the airbox is still as standard

[sparky]

oh yeah its a 91 mk2 model

[NaBz]

http://www.crm250.com/modifications.asp

[sparky]

i found that but couldnt find what jet sizes to use for the mk2
it says what to use on the mk3 but with drilled airbox but i dont want to drill holes in the airbox i need it standard really as to not let to much water in when im out

[NaBz]

try them and see how it is trial and error i guess!
hope not to much on the error side tho

[sparky]

hopefully not
who does the jets for them is it main dealer or places like lt?

[scrubs]

Leisure trail usually have a selection in stock. Can't remember the price but they are pretty cheap so It's worth buying a
few sizes to experiment with.

[sparky]

cheers i'll order a few ready to try
for when i get me barrell back

[scrubs]

Hey spark I have been giving this some thought.
and this may give you a starting point.

If you have an aftermarket performance aifilter installed..
(maybe worth getting if not) try going up just 2 sizes on the main. (keeping the original pilot)

If you decide to do the airbox mod at any point go up one more size on the main (still keeping the same pilot)

Change the pilot one size up - for every four sizes you go up on the main.
This is just theory and I would be interested to see how that turns out.

[sparky]

cheers
iv looked for an aftermarket performance filter but cant find one
where do you get them from?

dont think i will end up doing the airbox mod as there is some quite deep water where i go greenlaning which comes up probably as high as the box and would prefer to keep as much water out as possible
my barrell is expected back next week so i'll go from there with it

[scrubs]

I think most people seem to use the Twin-air filter. The CRM's share the same airfilter as a XR250/XR400
So you may have better luck searching for an XR filter as not many places advertise that it fits CRM

[sparky]

thanks for that
just another question are the reed valves supposed to have the metal cage on it see pic


mine doesnt have the metal pieces it only has the screws with little washers holding the reeds in ?

[Jonorow]

usually depends on the reeds. the boyesen 2 stage reeds have their own plate, but if they are standard reeds then there should definitely be a reed stop in place. jon

[scrubs]

Yes keep the reedstopper on. I think you only remove the stopper on the Boysenns (or however you spell it ) since they have the metal screw plate. I have the aktivs also and made the mistake of not fitting the reed stopping cage, then realised I should have, so had to strip it back down again staight away fit a new gasket etc..

Moto air filters is another brand that peeps use too.

[sparky]

i have no reed stopper fitted at all when i took it apart its the first time iv took anythin off since i got the bike
the reeds i took out looked exactly the same as the aktive ones i got from lt
just thought it was strange to only have screws and washers holding it in place!
i just bid on the ones in the pic on egay but got outbid at the last min