Need help with jetting

[Savage]

My DRZ 450e isn't getting the best fuel mileage. A guy online told me it is the FMF jet kit. My bike has plenty of power for me, so I'm willing to lose a little to gain more mpg. Where can I learn more about how to get into the carb and rejet everything? I don't know boo about jets. OR is there somebody around that is a whiz with jets that I can go to?
I'd rather have a bike running with bad mpg, than to tear into it and have it not running at all.
Help

[slimtrader]

I didn't see in any of your posts what kind of sprockets you have on that bike. The E comes with "lower" Gearing than the S. I change my sprockets out depending on what type of riding I do. I use the factory S 15-44 for mostly street and dirt road riding and 14-47 for tight slow trails. I have a second rear wheel with off road knobbies and larger sprocket. If the guy you purchased it from road mostly off-road he probably kept the stock E gearing but maybe he changed out the front sprocket to a 15 for a little more speed and lower rpms on the streets. I don't know. I think I'd check the sprockets first and make sure you are geared higher for best milage before messing with the jetting. It's usually stamped on the rear sprocket but you have to count the teeth on the front most likely.

BTW you say you get poor mileage but you haven't given what the mileage is. Mid to high 30's

Your bike has lots of nice power upgrades that lots of riders would love to have but I suppose the trade off is the lower milage. You would have no trouble finding someone with an "S" model that wants to do more agressive off road riding to trade with. I would like to be first on the trade list if you are looking at that option. Your bike would even qualify for some extra cash in your pocket after the trade because of the upgrades you have. Only thing to determine is how much.

[Savage]

Let's don't go there yet.
It's gears 15/48. When my MC mags come in I'll probably be ordering tire(s), handlebar risers, and a 44t or something like that.
Checked my mpg on my 1st full tank and I'm embarrassed to say it was 35mpg. 2 gallons, 70 miles to hit reserve. Most of my riding was casual on road because I'm just testing the bike out and wanted to see how many miles I could get. Dissapointed.
I've leaned the air/fuel mix screw a couple times and I'm pretty sure it's running leaner, but there's still soot on the exhaust.

The FMF jet #'s are: 128, 132, 136, 140, 144. Looks like the 140 is probably in it.
Got ahold of the previous owner and he said he would drop down 2 sizes when riding in Colorado. Told him I was looking for better mpg, he said I could try one size smaller and see what that does. I might try to put the 136 in, but I'm concerned on how to remove the carb and then get it all set back up properly. Anything to watch/listen for after I get it in.

The online guy said the whole fmf jet kit is junk. He said to go back to stock.
I have no opinion on this, so I'm just taking any and all advice I can to try and get better mpg and have a nice running efficient machine. It'd be nice if I could keep 2nd gear roll on wheelies too. j/k

Thanks for the help in advance!

[Hayden]

Lets start here. What carb is in the Bike?? FCR? CV? Ive done a few CV carbs of mine. Rejetting isnt a big deal.


Hayden

[Savage]

LOL, I'm a newb with the DRZ. The plastic is yellow... does that help? j/k
It's a 2001e and I gather they came with a flatside carb and I guess that's a good thing, so I assume he stuck with that. Does that help?

[Hayden]

After reading plastic is yellow............(Hayden bangs head on table...........bang....bang......bang) That would be an FCR. You may need some IGH That would be In-Garage-Help on this one. If I was closer I would have no problem tearin into it for ya and show ya some things. There all pretty much the same as parts and function go. If you have never done something like this before I would understand the hesitance on your part. Maybe someone closer will chime in and help also but really if you take the bowl off the bottom, the jets are right there. Easy to unscrew and swap.

None the less. Check this out.

http://www.teamcalamari.com/dox/tekcarb24.html

http://www.4strokes.com/tech/suzuki/drzadjet.asp


Hayden

[Harvey Mushman]

Someone had previously mention the Thumpertalk website. Go to the DRZ400 link and you will find a wealth of info there. On KTMtalk there are some pinned threads about the FCR carb as they are used on the KTM 4 strokes. There are some really good threads with many pics that discuss jetting, and mods to the accel pump that should apply to your bike. Go to the RFS 4 stroke link and you will find alot of good data. I know nothing about the FMF kit but have heard good things about the JD kits. I just bought an EXC450 and have got it running pretty good using larger stock jets, raising the needle and richening up the pilot screw. I may do the diaphram and O-ring mod to the accel pump, (this may?? apply to yours as well) but want to ride it more to get a better feel for where I'm at as it runs good right now. I would suspect the DRZ is capable of 40+ mpg when jetted right and not hammered on. Mileage can be affected not only by the jet size but the needle position and the length of the AP squirt, also by the gearing like Mike said. Study the links on KTM talk and check out Thumpertalk. This will help you understand how the different circuits in a carb work and gain confidence. The pics will help alot too.

Good luck

-Harvey

'98 RXCe620
'02 EXC300
'03 EXC450 (street legal)
'89 FXRS

[Savage]

I'm on TT but I'm getting plenty of sarcasm because I don't know poo about this bike yet.

My main hobby is nitro R/C's and I'm pretty good at tuning them and and tearing down the engine's so I think I can do this once I get a handle on what is what, etc etc.

Guy on TT said the whole fmf jet kit is junk, but I'm thinking about just installing a smaller jet and see what kind of mileage I get 1st.

So how do I remove the carb? Once I get it out I think I should be able to change out the jets.
Wish I had someone here to help walk me through this. It'd be more fun.

Thanks

[Savage]

Went out and looked at it and I want to tear into it but I guess I'd rather ride my 35 mpg bike than to have it out for a week from a screwup.

[Hayden]

Thats the attitude I was looking for (Hayden gives big thumbs up to computer screen)

Hayden

[Savage]

Is a little bit of "sooty" dirt on the inside of your pipe tip/sparky "normal"?

[xr-nut]

hey sav- its a 15 minute chore, once you get the hang of it and any stubborn bolts freed up. start here-you should have two large "hose" clamps holding the carb on the bike. loosen them considerably. you should be able to rotate the carb either direction enough to get to the 4 screws holding the float bowl on(basicaly the bottom of the carb). be careful at removing those 4 screws as the are quite posibly the cheapest screws japan could find, and will result in the most amount of work fixing if you strip them now! anyhow- once those are out and the bowl is off, the main jet will be visible right in the middle of the bottom of the carb. 5 or 6mm socket to remove. numbers should be stamped on the slotted end where the screwdriver goes. the pilot is right beside it, straight screwdriver to remove.

its pretty straight forward and id recommend you get in there and at least look around. be careful not to bend the metal that is holding the float, (black thing around the jets) and that is really the only thing you could hurt while there. check out this link, its the same steps with pics to show. good luck,
http://www.thumpertalk.com/forum/showth ... p?t=309069

[Savage]

ah so I don't need to remove the carb, just spin it? Sounds easier.
What does the main jet and pilot jet do? Simple terms.
Anything else to change while I'm in there?
Tell me if you think differently, but if I can get in it, I'm just going to put in a smaller jet in the hopes of better mpg without hurting performance too much.
I will bottom out the air/fuel screw and back it out __ turns? 2?

Thanks all!!!

[Savage]

I loosened the screws this evening and the carb wouldn't budge. Shot some lube on the carb and seals and let it set - still didn't budge. Are you sure there isn't anything on the top, backside that isn't letting it spin?
Thanks

[Savage]

Anyone want to cruise over here and help me with it this weekend?

[Kware]

My DRZ400S is getting around 51 miles a gal. I have made these mods,
Dyna Jet Card Spring and needle
Main jet is stock at 142
Larger Pilot jet, now 25, stock 21
Adjustable air screw, at 3 turns out
Air box mod with 3X3" opening
K&N filter
FMF muffler.
15/44 sprockets.

I have now changed the rear sprocket to a 41, which is what the "SM" comes stock with. I really like this gearing for road riding. It may not be the best woods bike now, but thats not my primary riding for this bike. I have not yet checked the mileage with the 41, but it should be better.
Now the carb on these bikes is hell to get out and back in. I know I have a different carb than the "E" model, but there is no room to work in that sub frame. There is a small tap in the rubber boots to make sure it is lined up correctly. This may be what is keeping you from turning it.

[Savage]

So what do I need to do to twist/turn the carb to remove the float?
Thanks

[Kware]

It will just be a wrestling match. The rubber tab isn't real big, it's just there to line it up. If you can't twist it around to remove the bowl, then you will have to wrestle it out of there.

[MacWildcat]

You might find it helps to take the throttle cables loose from the carb. Probably still easier to take the seat and tank off to see what you are doing. I'm fine tuning the jetting on the KLX400 also. I get a ping at 45-50 in top gear. Figure I'll try moving the needle up one notch. Here's a YouTube video that shows airbox mod and carb removal for a DRZ. http://www.youtube.com/watch?v=VtKWbs0N ... re=related

[Savage]

I'll check out the video and I just sent you an email. Looking for some "real life" opinions on the jetting of my bike.
Thanks