CRF's Only Forums

So I'm adding the #42 pilot, CRF only fuel screw, changing to fourth position and JD's jetting kit. It took me forever to get the carburetor out, so naturally I only want to this one time (if possible).

ANYTHING ELSE I SHOULD DO WHILE IT'S OUT?

oh what size main should I get, I may also open up the air box ????

You could have done all of that without removing the carburator.

What year is your bike? You may want to replace the accelerator pump cover with the Boyseen APC as well as add the "O" ring to the AP timing screw.

Can't tell you what main jet to use since it will depend on your altitude and temps (which you didn't list). If you have the JD jet kit it should give you your answers on the jetting.

while you have the carb off it would be good to replace the bowl phillips head screws with ss hex head screws.

DO open up the airbox if you are using the JD kit.

If you do a search on this topic you are sure to find a lot of information.

Sorry -

05
52-65 degrees

Where can I find instructions on the air box mod?

What is your elevation?
Air Box Mod....1 link & some pics from Mr Smith.

http://www.rickramsey.net/CRF250Xlg/TheWrench.jpg

Drill out the rivets and remove the snorkel. Then use a dremel tool or something along those lines to cut away the top of the air box. ( I carefully used a sawzall with a short metal blade) I left my air box in the bike and air filter in as not to get shavings in my carb, be careful not to hit your air filter. When your done pull it out and blow off your filter. Removing you backfire screen will make it breath a lot better too.
If you do this mod you will need to adjust your jetting. JD Jetting has all your jets/ needles and simple instructions. HIGHLY recommended!



Here are some good pics from Mr. Smith...




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Ryan B wrote:So I'm adding the #42 pilot, CRF only fuel screw, changing to fourth position and JD's jetting kit. It took me forever to get the carburetor out, so naturally I only want to this one time (if possible).

ANYTHING ELSE I SHOULD DO WHILE IT'S OUT?

The JD kit will walk you through the set up. Most likely it will call for the 158 Main Jet.

The AP mod with the O-rings and timing screw makes a big difference with Bog as well. Easy to do while carb is out.

I agree on changing the float bowl screws to stainless allen heads, makes it so much easier when you have to go in again.

The JD kit will walk you through the set up. Most likely it will call for the 158 Main Jet.

The AP mod with the O-rings and timing screw makes a big difference with Bog as well. Easy to do while carb is out.

I agree on changing the float bowl screws to stainless allen heads, makes it so much easier when you have to go in again.

Sweet! Thanks - does the JD Kit come with information on those additional mods? I assume not for the bowl screws - but I'm talking about the AP mod w/ o-rings and timing screws..

Ryan B wrote:Sweet! Thanks - does the JD Kit come with information on those additional mods? I assume not for the bowl screws - but I'm talking about the AP mod w/ o-rings and timing screws..

Ryan,

I sent you an e-mail with a PDF file going thru the whole AP mod with nice pics, etc. Most of us only do the first part with the o-rings.

Also on the Stainless Allen head Screws, these are the sizes:

Idle-adjust bracket - replace stock screw with M4x10 and M4 lock washer.
Float bowl - replace four stock M4x14 screws with M4x16 screws (no one seems to stock the M4x14 in stainless) plus M4 lock washers. If you don't use lock washers, one of the M4x16s will not fit; use an M4x12 instead.

Agent
I have found an abundance of M14's stainless up here at a specialty store. If you are having trouble I would have no problem sending you down a few boxes and you could supply my southern brothers at your leisure.
just a thought... ahhhh, the metric system.
later... Van

Agent,

Could you please email me that info on the AP mods as well? In the instructions for the JD kit it has some info on adding an oring to increase pressure. Is this the mod you are talking about? I would like to do this while I have the carb apart this weekend doing the kit.

Thanks

Agent - You are the freakin man !!!!