converting to fcr on te450 2004

[nyabinghi]

so i'm putting a fcr 41 in place of my mikuni on my 04 te450.

i ordered a jet kit from jd, hoping that it will be close....

what else do i need to switch? cables? airbox? it appears the intake side will fit, but i don't think the airbox side will fit without modification... do i need to get an 05 and up airbox to make it work? should i dump the tps?

anyone done this mod and has any tips?? jetting?

[studio5o]

Sorry I cant be of help regarding switching carbs.....but I did read your non-starting thread and thot u worked out the bugs......any reason for the switch?? I have the same bike as u and was wondering the benefits of switching...thanks Alex

[nyabinghi]

original carb had issues. a few gaskets/rubber parts had swollen up and were rendered unusable. mikuni/husky said parts are n/a. i switched because the fcr is readily available, with cheap parts, easy to work on, and tons of data is available on them...

bike starts easy now. i just need to jet it and it should be good to go. don't know if there is any performance difference. just ease of use (for me anyways..)

i've modified my original throttle assembly to open the fcr all the way (even with new cables it wouldn't open all the way (throttle tube fouled housing)- i ordered a crf450r throttle and cables to replace stock throttle...) i had to re-wire the tps to match with husky harness (switched from female to male plug) i'm gonna make an adapter for the bellmouth, as it's the airbox boot is just kinda clamped on there (fcr i got had smaller inlet on airbox side).

the previous owner cored the stock exhaust, so there's almost no backpressure. i'll need to jet for that, and hopefully some permatex copper seal will fix leaky midpipe (but it moves so much at wot even with a clamp on it...i'm gonna probably slice some crimp lines in it so the clamp will compress the joint..)

[studio5o]

gotcha.......sounds like a good plan......I too was having starting issues and looked at the mikuni....but when I hooked the battery up to my boat battery she fired right up.....got a new battery on order and we'll see if that's the culprit...thanks for the info.....good luck with the conversion....Alex

[Dave Hopkins]

Back in 05 when Husky first switched to Kehein, I had the first bike in the area and took it to JD, let him use it for testing to make up his Husky kit. 42 pilot, red needle and I think about a 180 main? Maybe 185? whichever he has it right! That bike was (I just sold it but still is) perfect!

You will also need to reduce the squirt of the accelerator pump. How that is done will vary with what year of carb you have!

Did you buy new or used?

Does it have a plastic cover on the right side to cover the AP pump linkage?

Metal cover?

No cover?

DOes it have a removable air bell on the rear? Or cast on air bell?

Does the spool turn clockwise to open the throttle? Or counter clockwise?

Part of the reasoon I ask is the reason your carb died is the rubber in it was not friendly to modern (last few years) gas aditives. The same issue exists with the Kehein if you get older than about 2002 (no I do not know the exact date, I have tried to find out and nobody knows)

[36MotoMarc]

This info pertains to putting an FCR37mx on a 2004 TC250, it may be of help since no install details were given thus far.

I used a FCR37mx purchased new through Honda, originally for a 2005 CRF250R. Remote hotstart and adjustable leak-jet.

The stock throttle cables didn't have enough free cable to use. Rather than buying a complete Honda CRF throttle and cable assembly, I modified the stock cables. By pulling the cable free at the throttle you can CAREFULLY snip the wound springsteel housing away, effectively giving you more free cable. The carb-ends slip into the FCR just fine. It worked like a charm, I'm running my oem cables/throttle.

Although It appeared the airbox boot was too large for the intake bell on the FCR, it did actually squeeze down to a tight fit. Crank it down with a socket, it will work. I bought a used '05 and up airboot (same for all models 250, 450, etc) only to find out it was THE SAME, despite different part #'s from 04 to 05-on ( got a great price from FUGI, thanks again!) so no big deal, lesson learned, hope that helps you. The FCR is narrower from intake bell to intake spigot, though, and it wouldn't fit in both without stretching it seriously. Fearing it would pull out in extreme landings, I made an intake manifold spacer to move the carb back. I used 3/8 inch aluminum plate, and had to freehand-port/machine it. A real P.I.T.A, but the end result was excellent, I can post a picture if you want. This brought the carb back, and solved the problem that the 17mm mainjet access bolt was hitting on the starter motor. None of this paragraph may be an issue to you, due to the taller jug/larger head on the 450.

I used the mikuni choke cable setup and ran it to the hotstart, using parts from both carbs. Now hotstart is where the choke was (outta mess up some future owner!). Choke is accessed under tank, easy to find once you know where it is.

It starts like a dream now and hopefully lost a wierd power drop when landing from jumps (not a bog really just went flat .5 seconds). I'm "wifing" it out for my spouse and wanted it to start easy and run cleaner. Also lowered it front and rear, fresh plastic/graphics, etc.

[Dave Hopkins]

36 motomarc

I think if you bought cables for an 05, or for a KTM say 450EXC 03 or newer the cables would be a non issue.

The carb Honda sold you is a newer style with the cast inplace air inlet where the prior one had the bolt on as did my 05 Husky, KTM got that style in 06, not certain when/if Husky got it

[rec_rider]

Just going through some of the old postings and had to add a comment on this. I swapped out the Mikuni on my 04 TC450 for an FCR 39 (I didn't go for the 41) but I had done quite a bit of research before doing so. What I found out is to not use an FCR off of a Honda since the airbox bell is not removeable. Also, the TPS has to be rewired. I bought an FCR from a YZ426, ordered a new airbox adapter and gasket, then installed it. TPS plugged right in and I even used the existing throttle cables.

What are the issues? The accelerator pump is very close to the exhaust but turning the carb slightly helps (no issues with doing so). The tank sits pretty low so you can't get to either the hotstart or the choke. To fix the hotstart I added an electric remote hotstart (love this thing!). I had to protect the wires coming out of the solenoid since they rubbed on the inside of the tank. For the choke I rigged up a long stiff wire to the knob that I could pull out then push back in. It's not in the way and works perfectly.

I think that's it. If I had purchased an FCR from a Honda it would have been much more difficult, at least that's what I thought. Even though it's not a 41mm I'm extremely happy with what I have. Without the carb upgrade I probably wouldn't be riding it today. BTW, still running on original valves even with years of riding and numerous GP races under my belt.

John