Barbarian Jumper Modification for Gen II bikes

Yamaha FJR Motorcycle Forum

Help Support Yamaha FJR Motorcycle Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Did you make the adjustments with a new ECU? After the ECU change on my '07, adjusting the CO values made the bike run worse.

 
so, what's done or different on the Gen I?
Ya ! what about us lowly Gen1 guys. Help us out here for the love o pete!
Well gents, the reason someone finally went through all this trouble is because there was no clear-cut write-up on the Gen II BJM like there IS on the Gen I.

Clicky Here! :dribble:

Which came from here: Clicky :blink:

Which you should have read as soon as you joined the forum! :rolleyes:

Just sayin'... ;)

 
To answer a question posted here, my BJM and CO adjustment were done after the replacement ECU was installed by the dealer on my bike. That is, first came the new ECU, then came the adjustment. From what I've read, the new ECU is no different than the old one in regards to the CO settings that are adjusted. The only changes were made to deal with the high altitude throttle response problem.

And yes, the Gen I stuff is already there, so check it out. This was specifically for the Gen II crowd. The only real differences between the two are the holes where the wire and plug are for the BJM and different screen views for the CO adjustment.

 
Last edited by a moderator:
Really outstanding job writing up a procedure. I have an '07 that runs "perfectly" but throttle response off of idle a bit sluggish -going to give the Barbarian jumper mod a shot. Thanks Jon for excellent work and taking the time to share it with us less gifted folks! :clapping:

 
Thanks, I just printed it up. I'm going to learn how to work on this thing, slowly but surly and that's a good thing.

 
Okay I did it. Talk about peeling an onion. SHEESH they got that thing layered in there. Rather crawl through an avionics rack on an airplane.

BUT, its done. I found all my cylinders balanced to 10. Now they are all 17 as suggested, up 7. Hopefully this is a good thing. Bike started right up with no issues. Tomorrow I will use the "SEAT O' PANTS DYNO" and see how she runs.

Directions were spot on. Thanks alot for your effort.

 
Okay it is done. Seat O' Pants Dyno says.... :yahoo:

Now, how does this in anyway impact gas mileage?

The bike seems a lot smoother throughout the power band. Hard to believe but it does. Also, seems the power comes on a little sooner. Not as much starvation up towards the rev limiter.

HEY, I ride this bike LIKE I STOLE IT. Except when the GF is on it. Then it all smoove...... Cool mod.

Just would like to know about how it affects the MPG? Guess I will be figuring that out soon enough.

 
Guess I will be figuring that out soon enough.
I am VERY curious as to your new MPG's. :huh:

This is what I am noticing so far:

Bike starts easier. Have yet to experience the random, put it in gear and have it stall.

Idles much nicer and smoother. No idle dance at 1100 RPM.

Has a nice throaty sound as you roll on the throttle.

Instant MPG readings at 80 MPH and tachin 4000 is around 45 MPG.

Power band comes on around 6 g's vice 7000.

Engine just seems to run smoother and be more responsive

More to come as this weekend we are taking about a 300 mile trip. Will report in afterwards. Maybe...

 
The Barbarian Jumper was first done on a '03 bike. The guys that figured out how to activate the CO screen actually tested their bikes! They drilled the head pipes and riv-nutted in 4 'bungs' then inserted a 4 channel Exhaust Gas Analyzer to measure the real effect of the CO adjustment. They found that bumping the CO readings 7 for each cylinder took care of the lean surging and smoothed idle without taking the exhaust out of factory spec. They also found that the CO adjustment only altered emissions at very low RPMs. The effect of the CO adjustment on the '03 engine was so small that it shouldn't change gas mileage at all or effect the cats.

I'm not aware of anyone that has done the 4 bung/EGA/CO test since. The ECU and fuel pressure regulation in the Gen II is way different from the Gen I.

Normally I would say that there should be minimal change with just the CO adjustment but Wicked Webby managed to make his motorcycle run really strong with air box alterations and CO adjustments. He has Dyno slips in hand.

 
Last edited by a moderator:
The Barbarian Jumper was first done on a '03 bike. The guys that figured out how to activate the CO screen actually tested their bikes! They drilled the head pipes and riv-nutted in 4 'bungs' then inserted a 4 channel Exhaust Gas Analyzer to measure the real effect of the CO adjustment. They found that bumping the CO readings 7 for each cylinder took care of the lean surging and smoothed idle without taking the exhaust out of factory spec. They also found that the CO adjustment only altered emissions at very low RPMs. The effect of the CO adjustment on the '03 engine was so small that it shouldn't change gas mileage at all or effect the cats.
I'm not aware of anyone that has done the 4 bung/EGA/CO test since. The ECU and fuel pressure regulation in the Gen II is way different from the Gen I.

Normally I would say that there should be minimal change with just the CO adjustment but Wicked Webby managed to make his motorcycle run really strong with air box alterations and CO adjustments. He has Dyno slips in hand.

Did the mod a couple of nights ago. The butt dyno says it may be stronger in the low end now, but I haven't owned mine long enough to really know the bike anyway.

Mine's still waiting on the recall ECU to arrive. Once that's in, I'll try before / after adjustments with the new ECU and see if it makes a difference.

This was an excellent illustration and instructional walk-through... Thanks for publishing this mod!

 
Quick questions. I'm going to give it a go this afternoon and I'm wondering if I should disconnect the battery first. Didn't read anything about it. I just don't want to let the smoke out of anything. I hate it when that happens.

Also if the battery is disconnected later does it go back to the original settings?

 
No need to disconnect the battery. The CO values are held in permanent memory, so they will not reset after disconnecting the battery.

 
Top