Jump to content
Sign in to follow this  

Trying to put a Keihin FCR33 carb on my XR250L

Recommended Posts

A while ago I bought a Sigma Kit, was very satisfied with it, then a mechanic friend did a weld job and burned down my XR 250, it was rebuild but after that I always had problems with the carb, so I decided to get a PD Carb from the "R"-series, but it didn't fit, because the electric start motor was in the way, I checked many website and I came to the conclusion that the Keihin FCR 33 might be the right deal for me. The Original Keihin from the "L" series are very hard to find and very expensive, the FCR is now being fitted and I hope for some good results.

If anyone has tried that set-up please let me know, maybe we can exchange informations.

Share this post


Link to post
Share on other sites

Happy, happy, happy, this is all I can say, about the new carb, it's fitted now and the very first impression are outstanding over the stock carb, the response is unbelievable and the power development is perfect, the rest will be fine tuning, it still sputters sometimes, I will modify the air box and will see, if I will get improvement, now my XR feels like a motocross bike - nice, memories came back.

I will post pictures later, unfortunately I didn't document the whole process.

Share this post


Link to post
Share on other sites

So here's some shots as promised, from the finished installation, FCR33 is probably the only carb that will fit a on XR250L 1997, I know you don't get those in the U.S., but Europe and Japan has plenty of them.

20130713_105845_zps700a9b01.jpg20130713_105830_zps9621218a.jpg20130713_105820_zps0628bbee.jpg

I will be doing some test rides and will check, what needs to be improved, so far great, let's see how good it is at some technical single trail.

Share this post


Link to post
Share on other sites

Awesome. You didn't feel like cleaning it up a bit before putting it on? 😉 Just jabbing ya. 🙂

Share this post


Link to post
Share on other sites

Awesome. You didn't feel like cleaning it up a bit before putting it on? 😉 Just jabbing ya. 🙂

:lol:Hahaha, does a dirt bike need to be clean? But actually you're right, could have cleaned it before...well just blame it on my mechanic

he put it on 🙄

Share this post


Link to post
Share on other sites

Would appreciate a couple of pics showing clearance for cables etc. If you took them from a little farther away it would help.

I personally don't care if it is dirty,shows you are riding your bike!

Edited by firstplacephoto

Share this post


Link to post
Share on other sites

Would appreciate a couple of pics showing clearance for cables etc. If you took them from a little farther away it would help.

I personally don't care if it is dirty,shows you are riding your bike!

O.k I will do that, just give me a day and I'll post them 👍

Share this post


Link to post
Share on other sites

Would appreciate a couple of pics showing clearance for cables etc. If you took them from a little farther away it would help.

I personally don't care if it is dirty,shows you are riding your bike!

that's my best try to get better pictures of the carb

20130715_072731_zpsf34661c7.jpg

20130715_093054_zps2e0b3bfe.jpg

20130713_105811_zps90060902.jpg

20130715_072734_zpsbdfbeb20.jpg

Share this post


Link to post
Share on other sites

O.k. so here's some opinion about riding off-road with this set-up. It feels like there's more torque from the bottom, I can ride a lot of up-hill sections in the second gear, this is nice and faster then usual, at very steep sections I had trouble getting up, the carb would bog or the engine just dies (never happened with stock carb). As I said before I really like this carb a lot, it is always delivering no matter what gear I am in, that gives the impression, that there is more torque. The downside so far is the gas consumption. With my stock carb I am able to ride somewhere near 160 Km's till I switch to reserve, the FCR 33 only gives me half the range, this is frightening. Maybe I have to swap the jetting or just fiddle around with the carb, I mean 50% more gas consumption is a lot. If there's any people out there with this carb or even the FCR 35, would be nice to hear from you. I am interested what kind of mileage you get out of a full tank with those carbs. Thanks a lot.

Share this post


Link to post
Share on other sites

I replied to your PM - just PM me your e-mail address and I will send you jetting specs for fcr35 on a '94 xr300.... It will use more fuel than the stocker especially in tight terrain - it has a very aggressive accelerator pump on the carb..... But only getting half the mileage you got previously - I'd say something is "off".

jeff

Share this post


Link to post
Share on other sites

 A little update, for those who are interested in this thread, the FCR had a 112 MJ and 45 PJ, the needle was on the 7th groove. This is crazy and how I got the carb from the previous owner, now we jetted it to 140MJ/40PJ, actually now it is running worse then before and still uses to much gas, about 1L per 10km, which I think is crazy, my XR 600 doesn't use this much and has a 41mm Mikuni. Now we're trying to figure out what's wrong with it, anybody that can post settings for the jetting, it would be highly appreciated.

 

Hope somebody might give me an idea, seems like we're stuck at the moment.

Share this post


Link to post
Share on other sites

Better rich than lean.

If the bike starts easy now and runs good at idle. I'd start going down in sizes on the main jet, and adjusting the neeldle clip. Especially the needle since it controls the midrange, and that's where you spend most of your time, and if its set low (meaning the needle is higher) allowing more fuel.. And these things have that aggressive accelerator pump that shoot alot more fuel when you crack the throttle i can see where your mileage is going! So, why not drop one main jet, size, and raise the needle clip position to lean it out some. And go from there.

Share this post


Link to post
Share on other sites

Possibly the accelerator pump, which is adjustable, is the cause. Every time you advance the throttle the carb squirts a little extra gas. 

I wished it was but it is not, I tried it without the AC Pump, just the same, I know about the "Taffy" mod, but as I said I unhooked the AC Pump to see the difference, but it was still exactly the same. Gotta find something else, I reckon

Share this post


Link to post
Share on other sites

Any update on your carb issues?  I've put an e start in my 92 XR250L and am struggling with the carb clearancing the starter.  Your carb looks like the solution, but were you able to dial it in?

Share this post


Link to post
Share on other sites

Any update on your carb issues?  I've put an e start in my 92 XR250L and am struggling with the carb clearancing the starter.  Your carb looks like the solution, but were you able to dial it in?

I have tried many different carbs on my XR250L and they all worked more or less perfect, my main concern was the fuel consumption, it felt great and transformed the bike into something desireable, but the fuel consumption was so bad over the stock carb, that I returned to stock carb, also bear in mind that if you get a FCR carb it is not bolt on, you need to have a spigot made for it to fit the intake and airbox manifold, I spend a lot of money on carbs, but at the end I returned to stock

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  

×
×
  • Create New...