I know of a XR650R with FCR that got 23km/l, my TE610 with FCR gave 27km/l once, 525 gave me 22km/l, CRF 450 X gave me 24km/l (cruising obviously)- no way a FCR should give 14km/l on a DRZ. Something is wrong.
Jacques, do you know what jetting and needle clip settings you had? Also was it the standard carb kit i.e. not an aftermarket kit like DynoJet?
A friend of mine had a DRZ400E as well and he also said he used to get about 21km/l on his.
No idea, came of a crf 450x. Offroad cycles jetted it for my 440kit
Ahh, maybe that's where the difference is. If I am not mistaken, the CRF450X has a FCR39MX carb and the DRZ has the FCR39 Single carb. They are quite different from what I understand.
My bikes performance characteristics are as follows:
- It's top end is ok. I can get about 155km/h. This would improve a little with a larger main jet I think.
- Mid range and quick throttle opening is spot on. Smooth and fairly responsive without being brutally snappy.
- Idle (crappy)
- Throttle just cracked open with near no load on the engine, the bike hunts. It's frustrating but not noticeable on an adventure ride, only irritating in traffic where this throttle position is used a lot. I haven't really noticed if this is better when the bike is cold or hot.
- The bike starts quite easily but does need choke sometimes.
- Fuel consumption: about 14km/L. Riding offroad vs on the road at about 110km/h doesn't really change this much.
I'm confused about the cause of the hunting at low throttle/load condition and the crazy heavy fuel consumption.
The jets I run are:
Location: Johannesburg so altitude is roughly 1750 meters.
Pilot: #45
Main: #152 (I think 160 is stock but I've read conflicting report here. Some locations come with a 145 stock but maybe that's in the DRZ400S, not sure.)
Leak Jet: I can't see what mine is. Standard is a #60.
Fuel Mixture screw: 2.5 turns. I think I should return mine to 2 turns out.
Needle position: 3rd from the top.
Float level: My little tab on the needle is exactly horizontal. Not sure exactly where the fuel level is sitting.
I've removed the coast enrichener circuit on mine. This little device enrichens the bottom end circuit on overrun and coasting to eliminate the popping (backfiring). Mine doesn't pop at all, even after removing this circuit indicating that it certainly isn't lean on the bottom end. I chose to block off the little nipples as opposed to connecting them when I removed this circuit. This actually calls for a different size air jet which I didn't do. I'm going to connect these two nipples together instead which is not supposed to need any change in air jet size (will try it this weekend).
My fuel mixture screw is a little far out at 2.5 turns but it's such a ball ache to adjust it (carb needs to come out).
I tried running my bike with the throttle position sensor unplugged. The ECU then falls back to a default closed circuit setting for the ignition timing which is only variable at lower RPM's. The bike ran well but I did find that it would run on a little when tapping off the throttle. With the TPS plugged in, the overrun behaved more normal and the bike runs a little better but there is no difference in fuel consumption.
I've read a lot of complaining about the DRZ bog when you crack the throttle. Mine doesn't have this problem at all. Now this can be improved with having the needle position in the correct position (which is the correct starting point) but the correct way to fine tune it on the pumper carb is the fuel accelerator circuit. This injects a spray of fuel into the carb when you crack the throttle, thus enriching the mixture for the acceleration.
1) There are two factors here, the timing of the fuel accelerator spray i.e. exactly when it sprays. Too early and it sprays onto the back of the slide becoming ineffective. Too late and the slide is already too far open and the lean condition has already been caused hence the bog. Timing of this should be so the spray just misses the slide as it's pulled up.
2) The duration of the spray. The pump diaphragm creates the pressure required to pump fuel into the accelerator jet. Different diaphragms are available to tune this but these make huge difference and the place to start tuning this is on the leak jet. A shorter shirt will result in less enrichening on acceleration and possibly still a lean condition. A longer squirt will result in more enrichening and possibly a rich condition. By adjusting the size of the 'Leak' jet, you can manipulate the duration of the spray. The leak jet actually allows excess fuel to return to the bowl when the accelerator pump is actuated. This is kinda counter intuitive. To create a leaner mixture on the accelerator pump, you actually need to go up in size on this leak jet
because it allows more fuel to return to the float bowl as opposed to the jet stream. I haven't messed with this.
Anyway, food for thought if anyone has anything particularly intuitive to add, I'm all ears.
Topic: My DRZ400E thread (Read 3723 times)
