400 E/XC - I Need A Little More Ooomph! Help!


triplephatmx

Member
Jun 5, 2001
65
0
Hey all! I have a 2001 400 E/XC and desire a little more, er, oomph?! I have had the bike since late winter and love it! BUT, being that I came off a 250 2-stroke MX bike, I am now wishing for a little more, shall we say, front wheel lifting power! Don't get me wrong, I love the power delivery of the 400 E/XC - very, very smooth - almost electric like. I ride mostly wooded trails and some MX, so I don't want too much and end up with a non-compliant bike in the woods. Anyway, here's what I'm contemplating - please offer experiences/opinions:

1.) Nobody here seems to like this idea, but I have heard good things about the New FMF Powercore IV Q(quiet) silencers. Many have heard that lafferty uses a 400SX silencer on his 400 E/XC to give it a fair power gain (mind you this is at the sacrifice of noise - which I WILL NOT do). So the new FMF Q is supposed to give the performance of the SX silencer with the stock E/XC decibels - interesting and I'd be willing to shell out $300 if it really is true! Thoughts on this one?!?!

2.) Change the gearing - maybe go to a 52 on the rear or 13 on front to try and get a little more oomph?! I know this is the least expensive option, but I end up affecting the ratio for all 6 gears - uggh! What have others tried as fas as gearing on this bike?!?!

3.) Jeb gave some great jetting specs that others seemed to be relatively pleased with - this is the middle of the road as far as expense (depending on how hard you get spanked for the needle - lol!!). But, I hear the FCR carb is a pain in the arse to work on - true or not?!?! Sorry I'm used to TMX's and PJ's (read - easy to work on). Thoughts on this?!

So my fellow KaTooMers, which mod, if I only picked one to start with, should I try?!?! Thanks a million!!;)
 

nephron

Dr. Feel Good
LIFETIME SPONSOR
Jun 15, 2001
2,552
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I gotta better idea. Go across the garage to the red one, and swing your leg over. That one is much simpler. ;)
 

jeb

Member
Jul 21, 1999
633
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Sorry if I come across with a bit of an attitude here but I'm having a hard time with this post. I gave you a jetting spec to do EXACTLY what you're asking for. We're talking about, at the most, a $20 investment for a $7000 dirtbike. Why haven't you already tried that?

I can't tell you about the quiet core. Seems most EXC/MXC guys are happy with the stock exhaust but a few have gone aftermarket. The SX silencer may be the way to go but you'd probably want to/have to switch it back to a spark arrested model for woods riding.

A lot of us that ride this bike in the woods have gone to the 13:52 gearing. That's what I'm running. My buddy also has an 01 400E and he tried just going to a 13 on the front after trying the stock 14:50. He said both are too high and he's putting a 52 on the rear now with the 13. The only drawback I've seen is that this bike will chew up 13's in the front pretty fast. Buy more than one. Also, make sure you get flat sided CS sprockets. The ones like the Renthal light sprockets will not work. They'll fit on the shaft but the bolt/spring washer will not get them tight. KTM and Sprocket Specialist and maybe Sunstar offer flat sided ones.

With the jetting and the gearing, I find this bike to be very easy to wheely. I'd sure try both of those options before I spent large on exhaust components.
 

triplephatmx

Member
Jun 5, 2001
65
0
Hmmmmm?!?!

Yeah, I guess the frustration level is a bit higher than I thought as I do take a bit of offense to your post! After all, who can say your jetting specs didn't run the motor too hot and purge that bearing of enough lubrication to cuase a failure on your bike? (HaHa - I'm kidding here!) Besides, I was giving you credit for offering a thorough, and what appears to be majority accepted, jetting guidline! You were unfortuantely the ONLY one that gave any useful information previously instead of the usual wasteful "funny" comments such as the first response to this post!!!!:p

So I haven't tried the 13T sprocket because I don't feel like throwing them away all the time and if I go 52T on the rear I really should replace the chain (need more links) to keep the wheelbase where I want it (that's $100 + the sprocket). The jetting I didn't do becuase I have heard a few negative comments and some obvious apprehension after recent "problems" - besides I am admittedly "gun shy" about working on the FCR carb simply because I have never worked on one before. It's probably simple, but I wouldn't know - I've only heard bad things from others?!?! So that's where I'm at!

So enough flaming, I was simply trying to reopen the duscussion in hopes of getting more opinions. I certainly didn't think I was going to piss anyone off - geesh!! We're supposed to be here to help one another. Anyway, if somebody else has any experiences they would like to share I would appreciate it!
 

Strick

LIFETIME SPONSOR
Nov 8, 1999
1,782
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Do you plan on keeping the KTM when the CRF450 arrives? If so, get the needle, and shorten the wheelbase with the 52t. My 300 handles a whole lot better since I shortened mine. I actually went the other way on the sprocket 52 to 50, and went to Michelins, which are lower profile than most. I am not a 4-stroke jetting expert (yet), but the news on changing the needle would make it a 'must-do' for me.

If you aren't going to keep the 400, I don't know I would waste any time or money on changes.

Good LucK my soon to be CRF 450 Brother!
 

triplephatmx

Member
Jun 5, 2001
65
0
Thanks for the input Strick! Yeah, I plan to keep the 400 and I can't help feeling like I am trying to build up the 400 to meet my anticiaptions on the CRF450 (I can't wait!!!). I decided to do the gearing change tonight and see how that goes and I will likely order the needle/mains next week. I just can't see dropping the $$$ for an exhaust, especially with the CRF coming. I have to wait until Feb to get mine though!! I can't wait to own a Honda again. Don't get me wrong I love my pumpkin for it's intended application, but the CRF will rip on the track!! Here's to some good ol' lever draggin'!!:cool:
 

Shaw520

Damn Yankees
LIFETIME SPONSOR
May 14, 2000
1,082
6
Sounds like you're in between wanting a MX bike and an offroad machine.

13:52 gearing will make a noticable difference. How often to get into 6th?
Running race gas will improve throttle response - mid range.
There is an available 454 kit, but with the CRF on the way, its doubtful you'll go that route.
The exhaust mod is probaly insignificant.
The jetting I wont comment on.
 

triplephatmx

Member
Jun 5, 2001
65
0
You hit the nail on the head - I AM in between wanting a MX bike and a woods bike!! I am eager to try the gearing - I am picking up a 13T and a 52T on the way home from work. I already run race gas for the exact reasons you stated, as well as for consistency. I have "thought" about the 454 kit but as you said, why? if the CRF is coming. But why do you have no comment on the jetting? No experience with it so no comment or is there more to it?! Thanks for you input Shaw520!!
 

trewent

~SPONSOR~
May 26, 2000
72
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I purchased the SX muffler for my '00 400 exc and it woke up the power band quite a bit, it still is quite compared to a YZF of any size. It revs quicker, more top, lost a little oomph on the bottom. Then I put a 13 tooth front sprocket on, made a bit of difference not gobs, did make negotiating log crossings a bit easier. The FMF Q is actually the same technology already on the euro exc's in '00. I do not know if it is still the same. (mine is a euro model) I have a thread going on uping displacement on 400's. There have been some interesting banter. I am still considering purchase of a 520, just to make life easier.
 

grunk250r

Member
Nov 16, 1999
144
0
OCEMN needle

hey triplephat....I have that needle if ya wanna buy from me ....still in the package....I bought the needle before the bike and now the bike deal fell through!!:silly:
 

Coach in ND

Member
Mar 19, 2001
212
0
The jetting specs from Jeb are a must do. It really woke up my bike and would recommend it to everyone with a 400.

I'm running a 14-54 on mine and it works O.K. but still could be a little lower for the real tight woods. I hate running a 13 on such a torque monster.....it eats em up!!!

The P.C. T4 exhaust really helps all over and saves some weight, but it's a little loud without the quiet core.
 

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