Miles Per Gallon Drop

[carolinakid1]

Stock 2007 Nomad (1600) with Cobra Fuel Module set at factory recommended pot settings. Getting about 32-33 mpg. Seems low. Was running regular gas. Just filled up with Exxon Premium and engine sounds a lot better. Any suggestions?

[recumbentbob]

Keep buying the premium OR adjust the FI controller OR both.

[macmac]

Yeah, turn all pots OFF, then ride the bike 8 to 10 miles, then set up pot 1 custom alone. The book specs are based on intake and exhaust mods you don't have yet.

All your setting most likey will be under the book values.

Set pot 1 alone, to best rpm, then pass that value so the engine boggs if it will. Then go back to best and pass that to lean, to really find best.

Once you find the real best, turn the pot richer just the tinyest smidgen.

Write that down on paper. Next to it write down what grade fuel it is.

Be prepared to re-set the black air idle knob under the right down bowl. If that has never been touched ever, you need to pull down on the knob to engage it's 2 lugs, and will a rag padded pliers turn it to break it free, as most seem stuck from the factory.

After that you shouldn't need pliers again.

Next go ride to some place you can get a little nuts and not get busted.

With pot 2 set to off ride like a demon is after you for 1/4 miles runs to feel this new difference.
First test is to be sure the bike doesn't feel like a runaway. Pot 2 is still off, and pot 1 is the only pot ON.

If rpm comes up and the feeling is as if the bike has it's very own mind re-adjust the black knob down, counter clock wise to get apx 950 rpm + / - 50 rpm.

Next ride the same way at pot 2 set at book spec several times. Better or worse?

If better go up on the dial if not go down on the dial, find best full blown scare the pants off ya possible.

No more than 3rd gear up too.. 4th and 5th are both over drives.

In general pot 3 should be a lower book spec anyway, you can tinker with that, but the ecu as is usually provides all the fuel you need at highway cruise.

I expect all the pots will end up at lesser values untill you do other hart parts mods.

And then with all the settings recorded on paper, when you need fuel again, fill with 87 octane and see how it goes.

That might mean testing with the pots as you have them and or starting all over again, but that isn't too bad a chore anyway.

Just turn off pots 2 and 3 and re adjust for best RPM after some fule has been run thru the system.

Probably just setting to book specs put you right into a overly rich condition on a otherwise stock breathing system.

All book specs are only ment to be a starting point. These are not written in stone, No 2 identical engines will use the same anounts of fuel. No 2 identical fuel moduals will be a dead on match to one another.

This goes for carbs too.

[carolinakid1]

Thanks...will work on it.

[cactusjack]

Not surprising. You are dumping more fuel into the engine than you were before. Without intake and exhaust mods, you aren't getting the benefit of that much fuel. If you smell the exhaust at idle, does it smell really rich?

Follow Mac's instructions and adjust the fuel module accordingly.

[AlabamaNomadRider]

Mac I appreciate you explaining fully what a person needs to do to set the Cobra. I have never worked on mine but I feel I can do it now with your instructions.

[rewindgy]

If memory serves correct - as stock bike Pot 1 was 1.5 Pot 2 was 2 Pot 3 off - if I kept it at or under 60 mph it was around 45 mpg - over 60 ish and all bets are off.

[blowndodge]

did you try Amsoil yet? ::)

[dandantmm]

Originally Posted by Blowndodge "Darksider"

did you try Amsoil yet? ::)

now that right there is funny. LOL!!

[cactusjack]

Originally Posted by Blowndodge "Darksider"

did you try Amsoil yet? ::)

S M A R T * S S !

[usranger74]

I ride an 07 stock. I ride solo and I ride mostly back roads and highways and keep her at 60 MPH or so. Day in and day out I get 43-44 MPG.

[skeeter]

Originally Posted by usranger74

I ride an 07 stock. I ride solo and I ride mostly back roads and highways and keep her at 60 MPG or so. Day in and day out I get 43-44 MPG.

me too except I'm usually 10% over the limit and sometimes two up.

and we know you meant 60 mph :)

[macmac]

All internal combustion engines need air to fuel mix to be set up for that particular engines breathing abilty.

No matter what any engine has on it, air to fuel mix should be set to the best it can be.

Each different intake set up filter set up and exhaust set up will make some difference in what that engine set up that way and again set up another way will burn.

The perfect ideal is 14 parts air to 1 part fuel. No engine is ever that perfect in all RPM power bands.

At one point or another something happens and the ratio breaks down. Could be valve float, could be too lean in a mid range over lap, and lots of things.

Over lap is a sharing of jets in a carb, but a similar thing can happen on injection.

In the case of 15's and 16's the ecu IMO is set to lean in idle thru hard accell phases. Ma Kawi knows that but must please the ever loving bean counters at EPA.

There is no adjustment so then the only thing we can do is add a modual and fool the ecu.

There is many bennies for it. We can run the correct octane for 9.5:1 comprssion for one thing, reduce engine stress, run cooler, get more mpgs and get more powder, depending on how the engine is allowed to breath.

[blowndodge]

Originally Posted by cactusjack

S M A R T * S S !

this is a tough crowd,,,, tough crowd I tell ya!!

[dank]

Originally Posted by skeeter

I'm usually 10% over the limit and sometimes two up.

Wow! 10% over the limit...so you drink a lot, and, well, err, we probably don't even want to know about the two up part.



(If you are going to chasten another member concerning units, then you should at least include some in your reply so we don't have to guess.) ;)