What is wrong with my new 2007 DRZ400E ???

Perhaps its supposed to be this slow, but surely not? When i took it for the first ride top speed was 84kph downhill. Say about 50mph. Bike is brand new, completely stock Australian model. Its got the FCR39 carb. I noticed onn the ride that with the throttle cracked all the way open, the bike spluttered and wanted to die - max power / top speed was reached with the throttle about 85%.

So i take it into the shed and get to work. The cap comes out of the muffler. Yes its loud, but we'll worry about that later. I pulled the snorkel out of the airbox. After searching, i find the little screw of the side of the carb that stops the throttle opening right up. Off it comes, sneaky bugger. Now the throttle twists heaps further. Good. Head back out to the street.

Its louder, and snappier, but still it splutters and dies with the throttle any more than about half way open. Weird. It doesnt just hesitate, it wants to die. If i hold throttle open im quite sure that ill coast to a stop.

Does all this sound normal? I dont know what the stock jetting is, i havent looked. Perhaps it needs rejetting but surely its not supposed to be this bad from the factory.

1. It is possible the bike wasnt warm - its pretty cold here right now, though i took it for about a 15 min ride.

2. Could it be flooded of something (???) i was playing with the throttle alot while i was working on it and could hear the carb pump working, but the fuel was switched off. Bike started fine...

3. could one of the jets be blocked, or obstructed? Bike sat in shop for a few months till i could drive down to pick it up (7 hours away hence the delay)

4. Could this be related to the ignition in any way?

Searched high and low but havent heard of this problem before. Please help me!

So you've pulled the snorkel off?

That means you've done the 3x3 with No rejet, that is one reason it now runs badly.

What alltitude are you at, as the factory settings might not be right for your alltitude.

Sorry to hear about your probs on NEW bike. If it was'nt 7 hrs away I'd say take it back to the dealer.

Wait for some more knowledgable gurus here on the forum to chime in but my guess would be a clogged main jet from sitting.

I'm sure a rejet or at least some tweaking in the jetting is needed to get the best possible fuel/air mixture. Especially since you pulled the snorkel, but your problem sound a little beyond the jetting being off.

Of your numbered questions three sounds like the problem.

Since you need to confirm the current jets/jetting anyway I'd pull the carb and take a look at what you got and see if that main jets clogged while doing it.

Again tho wait for some others to chime in and we do have some Aust. members that would prob be of greater help. I'm not familiar with the differences between our US models and yours.

Hey there's headster, he'll offer some good advice. Headster he said this was happening before pulling the snorkel.

Hey there's headster, he'll offer some good advice. Headster he said this was happening before pulling the snorkel.

hence why i'm thinking alltitude, but you could be along the right lines with a cloggged main.

Either way, i think the carb should be pulled and looked at.

Clean it up, and rejet for the 3x3.

Thanks for the replies and suggestions. Altitude here is about 230m / 800ft above sea level. Humidity is pretty low. Will this affect it?

Ill call the dealer today and see if they have any ideas. Im not sure what is involved in predelivery, but perhaps they've had the carb off. Ill make time this weekend to check out the carb for problems and the jetting information.

Ive read heaps on TT about the jetting but eveyone seems to be running aftermarket pipes. At this stage ill stick with the stocker (probably and endcap) and 3 x 3. Can someone point in direction of jetting with these simple mods?

If you have bought an Aussie E then the bike has a whole heap of EPA/ADR crap that is on there to allow it to pass EPA/ADR regulations.

What you removed is the Throttle/carb stopper that like you said only allows partial throttle.

What I can't believe is that the dealer did not tell you about this, all of them (dealers) are more than happy to take this stuff of for you and will rejet to suit.

Technically he does not have to tell you, but it would have been nice to been told "look mate, this bike is not at it's potential, here is what you do to fix it..."

I'd be annoyed if I was you.

You should not ride with the throttle stop screw removed. The one you removed was part of the government restricting the carb, you need to get the one that allows full throttle. Riding without a stop can enable the trottle wheel to go over center and cause the throttle to stick wide open.

You need to tell us what jetting is in the bike. You need to tell us what elevation. You need to expalin any issues you have with the way it runs.

Here are a few concepts to set the pilot jet, adjust the fuel screw and select the correct main jet:

Fuel Screw/Pilot Jet

Fuel screw settings in the 'book' are recommended starting points. Every bike is different, as is the temp and altitude. Set the screw according to this method.

Gently turn the screw all the way in. Now back it out two turns. Start the bike and fully warm it up, go for a 10 minute ride. Set the idle to speed to 1,500~1,800 RPM as best you can (I know, without a tach this is tough, just set it to were it idles relatively smoothly). Once warmed, slow the idle to the lowest possible speed.

*** When turning the fuel screw, keep an accurate 'count' of the amount you are turning it and record it in case you have to reset it for some reason. Makes life easier when you can just set it from notes Vs. going through the procedure again.***

Turn the screw in until the idle becomes rough or the bike stalls.

if it stalled, open the screw about 1/4 more turn. Restart it and slowly screw it in till you can just perceive a change.

If the screw can be turned all the way in and the bike still idles perfectly and does not stall, then you need to go down a size in pilot jet.

Now very slowly, open the fuel screw till the idle is smooth. Blip the throttle, let the bike return to an idle, wait say ten seconds. Confirm it is the same smooth idle.

If the screw has to be opened more than 3 turns to get a smooth idle, you need to go up a size in pilot jet.

If you find it does not stall with the larger jet but has to be open more than three turns with the smaller pilot jet, put the larger one in and set the fuel screw at 1/2 turn.

If the idle speed increased, adjust the idle speed knob to return the bike to a real slow idle speed. You must then re-visit the fuel screw. Keep doing this till the fuel screw is opened just enough to provide a nice steady idle at the lowest possible RPM. Once this is done, increase the idle speed to the normal one for your bike, typically about 1,500 rpm, but go by the spec in your manual.

Main Jet

Starting with the recommended main, remove the airbox door and go for a ride (bike fully warmed up). Is it better or worse?

If it is better, you need a smaller main.

Go down one size, replace the airbox door, ride. Remove the airbox door and test again. Better or worse? If better, go down a size again. Keep repeating this till the test with the airbox door is worse.

If it was worse with the airbox door removed, tape over 1/3 of your 3X3, test.

If it is worse now with the tape and was worse with the airbox door off, your main is just right. You are done!

If it seems better, you need to go up a size in main jet. Test it again (remove the tape). Replace the tape, test again. If with the tape on it is better, go up another size in main. Keep repeating this till having the tape on is worse than with it off.

To finish up and ensure you are set accurately, retest the bike with the tape off, ride it, then remove the airbox door. Best performance should be with the airbox untapped, airbox door on.

Remember, the main only operates at WOT. Ideally, you want to be in 3rd of 4th gear doing the tests, hitting max revs (just shy of the limiter) for at least 10 seconds to get an accurate representation of the jet status.

Be sure to keep notes of your settings. You may find you need to make a change, say if you're riding in the mountains or down at the beach. Returning home, it is a simple matter of referring to your notes to restore things.

The shop I bought my DRZ from took all the restrictors out pre-delivery.

I wasnt charged for this but some shops will charge about 1garage.php?do=viewattachment&attachmentid=60772

The shop I bought my DRZ from took all the restrictors out pre-delivery.

I wasnt charged for this but some shops will charge about 1garage.php?do=viewattachment&attachmentid=60772


The manifold restrictor.


What in the world............?

Why don't they just hold onto the keys for you? :thumbsup:

The manifold restrictor.


That would definitely put a damper on the bike's performance... :thumbsup:

The shop I bought my DRZ from took all the restrictors out pre-delivery.

I wasnt charged for this but some shops will charge about 1garage.php?do=viewattachment&attachmentid=60772

which side of the carby..air filter side or engine side?

which side of the carby..air filter side or engine side?

has to be engine side.

wow that sucks. whats the point, they mine as well only sell 50cc bikes over there:)

hopefully youll get that sorted. A bunch of people mentioned rejetting for your 3x3 mod but i didnt read anywhere that you had actually cut open the airbox yet. I would pull that intake restrictor out, like william said make sure there is a stop preventing your throttle from sticking Wide OPEN. and have fun.

Shame on you Suzuki Australia!

I found the potato in the manifold as described, so ive opened it right up. Dinner guests arrived last night as i was putting it back together. Ill finish it and take it for a test run today.

Thanks for the help. I think ill leave the jetting for the minute and have a look at it after ive been offroad. Im going to drill a couple of holes in the muffler baffle to find a compromise between noise and airflow.


Hope it works out for you westy, its really odd that these things weren't done by the dealer, almost all dealers here do these modifications as standard, mine had been done and i wasn't even told! I found out later..

You may not necessarily need a rejet depending on what you are happy with, but it helps.

I experimented a lot with my standard mufflers baffle for a compromise between breathing and noise also. The pic below was the best result;


My 1985 XT600 had the same type of restriction, bought it in Germany. Dealer told us about it and put the wide open manifold in for us. Bike ran great after that, definately more power.

its no big deal ... its done to pass emission laws . it means we can ride bikes like the CR500 on the road , just remove the rubbish and laugh . my only concern is that people are out there riding around with this junk inside .

Does the Aussie S and SM have the same potato?

Its all back together and ive been for a run. Goes great. It seems to spac out a bit right at the top end but thats probably a jetting thing. But its got heaps of midrange so itll do for the meantime. Thanks to all for the info.

At first i thought itd be ok, but ive resolved that its too loud. Steve, that looks pretty good. How did you arrive at the finish point? You started drilling holes till you were happy with the performance and decided that you didnt want to go any louder? Anyone else drilled holes of another design in the muffler cap thingy?

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