Jump to content
Sign in to follow this  

budgeting mods

Recommended Posts

I have opened up my air box, changed my head pipe to the dirt version's, and got a Keihin FCR 39 off ebay; it has a choke and no coast enrichener.

What jets should I start with at this point?

What hose fittings need to be hooked up, and which ones should be plugged?

Do you have pictures or diagrams that can help me locate the jets and hose connections?

Thank you,

John

Share this post


Link to post
Share on other sites

read sticky at top of page titled fcr conversion: the burned way

it has a list of part #'s and a full how-to

Share this post


Link to post
Share on other sites

I'm having trouble finding the thread your referring to. Do you know the date and time it was posted?

Thanks for your help!

Share this post


Link to post
Share on other sites

I found the parts list, but I still don't see the how-to.

I did find (Jetting the Flat FCR carb, DIY picture tutorial). This look similar to my carb. This should help.

I have the older FCR 39; do I use the same jets?

I'm sorry for the trouble.

Share this post


Link to post
Share on other sites

I'm using a diagram from Sudco to identify the jets. What size slow air jet do I use? And, (a jet not named in the diagram) not the main or slow jet but the other one in the trio. What size do I use?

My carb. has no leak jet (not drilled and taped). Is this a problem?

Share this post


Link to post
Share on other sites

I'm no expert in this area so can't help but when the experts do answer, I'm guessing they are going to want to know the elevation you'll be running the bike at.

Share this post


Link to post
Share on other sites

fcr and fcr mx use same jets and your altitude is under 3000' so you'll be fine with the recommended jetting with some fine tuning needed as you're at the upper limit of the sea level set-up range. Read the parts list included in the link aaronjohnston posted. I guess there is no how to in there-my mistake. If you are patient enough to wait a few days (as it has been) then maybe you're patient enough to read some of the threads dealing with fcr install-there are a ton of them here.

Leak-down jet-don't know the details but it is part of what determines your squirt duration. I would think your carb would have it-any idea what bike it came from? The fcr (aka "Flat-CR") is used on a lot of bikes and not all have accel pumps/leakdown jets. If you have one off a sport bike, you might have to do some drilling and plumbing. I dont know the carb that well so you'll have to get help from someone else- Eddie is the man for this. I would do as much research as possible (for your own sake and to make life easier on those trying to help you) and then, if necessary, start another thread asking Eddie for help. But get your ducks in row first, he's very busy.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×