Engine Dies
20 May 2019

posted by bullbalz - Benelliforum 20 Mch 06
Every couple of days, it dies when shifting from 2nd to first while slowing for a turn. I have always noticed it and just hit the starter button and kept going. Yesterday, I was getting off the highway and coming to a stoplight. I was braking and listening to music. I shifted from third to second, the engine died and I didn't notice it because of the music. As I let off of the clutch, the rear tire locked and went way squirrely on me. I kept it locked so it didn't pitch me and used the front brake to skid to a stop. It scared the crap out of me.
I'm usually at around 4K RPMs when downshifting and do a pretty good job of matching revs. Sometimes I think it dies when I pull the clutch, even before I shift, but I can't be certain.
Anyone else have this issue? Any ideas? I definitely need some help on this.

posted by JohnnyO - Benelliforum 20 Mch 06
I've had it happen to me on a few different Tornado's. It has always been under 3000 rpm with the clutch in; the factory don't know exactly what it is; I have a few idea's. First things I'd do is..... re-download the 6033 map into the ECU, get the idle CO set to 2.0% and open the air stepper (with the Axone tool) to raise the idle to 1,400rpm.

posted by dean100yz - Benelliforum 21 Mch 06
Mine did it too when I first got it. For some reason its pretty much stopped now. Either ways I was told my mechanic from Red Dog here in Essex/Kent, UK, that it had something to do with the screws in the airbox. He said to cure it you had to turn all 3 screws fully in, then 1.5 to 2 turns out (All the same). Thats meant to cure it. The ECU thing doesnt sound a bad idea either??? Although he never mentioned that, only that it must have the latest 6033 map (assuming yours is a std model). Mine ticks over at around 1200 i think and would stall at around 2-4k. You can't even bump the buggers, 'cos of the slipper clutch lol

posted by JohnnyO - Benelliforum 21 Mch 06
He's talking about the throttle air by-pass screws, I agree, I set all three at one & half turns out, this helps with off-idle lurch also (giving some progression to a suddenly opening throttle butterfly) but the butterflys have to be synchronized at the same time though.
As a quick test to see if my butterfly synchronization needs doing, I look at the exhaust headers when running at night, they should all glow with the same amount of redness (in neutral), if you have one that glows more red, you'll generally find that the butterfly for that cylinder is open a touch more than the others making that cylinder a little leaner, hence hotter.
I also remove the throttle stop screws for cylinders 1 & 3; cylinders 1 & 3 are linked to number 2, so they are not needed, I don't like the possibility of them confusing any tuning issues.
PS: I adjusted the air by-pass on my RS but it didn't cure the spit-back/cutting out problem... go figure?

posted by vxtbrit - Benelliforum 7 Apr 06
I agree that the Benelli maps need sorting, but interestingly during my recent modifications to the TNT I noticed that the air sensor was positioned in the corner of the air box just above the cyl head. now I think I’m right in saying these sensors are thermistors which work on temp differential.... the faster the air moves across the sensor the colder it gets, there by giving a variable signal to the ECU this signal as well as the throttle sensor controls fuel management. The problem is when the bike is moving slowly or is stationary the sensor is heated rapidly by the glowing power house (the engine) just below it therefore fooling the management system into immediately modifying the fuel/air mix (incorrectly)......I have repositioned and shielded my sensor to see if this theory is right will let you know the results.

posted by JohnnyO - Benelliforum 10 Apr 06
Hmmmmm (scratches head), you may be on to something guys, I was having a problem with my TnT race bike in the garage last night, the Axone was showing the air temp (via the bikes airbox sensor) at 50 degrees C when it was only 20 degrees C in the workshop, the bike was hesitating & mis-firing like it was lean.
If the on-board computer thinks that it is a hot day, it will lean out the mixture BUT funny enough, the CO exhaust analyzer that I had connected did not show it to be lean. I'll keep searching.....

posted by JohnnyO - Benelliforum 10 Apr 06
Okay vtxbrit, I think you have steered me down the right path, I repositioned the air sensor (well I just hung it out the front of the bike for the purpose of the test), my misfiring stopped, I played around with the Axone and leaned out the mixture and could induce the previous misfire.
As I said earlier, if the air sensor is getting warm (or the air around it), the ECU will lean out the mixture because it thinks it is a hot day, I guess this phenomena would be more extreme on a cold day?
At low rpm, the lean spit-back through an intake port would be enough to stall the engine.
I think I will mount the sensor in the front fairing, the temperature of the air in there would be much more exemplary of the air being inducted.... I think only for Australia though as we rarely get temperatures under 10 C degrees.
I think for the Tornado, you could mount the air sensor in either the airbox or radiator intake ducting but make a sheild so that incoming debris doesn't damage it.
It's still early days yet, I'll do more testing this weekend, I will also send my thoughts to the factory to see what they think.
I think this cutting-out problem that we (Tornado & TnT owners) have all been enduring could be over?..... stay tuned!

posted by vxtbrit - Benelliforum 11 Apr 06
See my TNT topic first ride since mods, very very happy, it seems all the starting and low end fuelling problems have almost gone I am getting it on the dyno next week then I have one more theory concerning the ignition set up and the way the stock ECU interprets information (or not as the case maybe).

posted by vxtbrit - Benelliforum ?? 2006
TNT - mods so far
my brother builds top fuel car engines (seriously clever) and has finally given the tnt a look over after testing inputs/outputs etc. He said the ECU (the brain) is total sh*t and wants throwing in the bin. It cant cope with sudden changes in input signals, which is exactly what an engine does. He reckons to put a 16 channel proper controller in would cost about £600, but then it needs mapping, which could take 2-3 days on a dyno (that’s the expensive bit, bearing in mind his company charge high 3 figure numbers per hour for bench dyno work) I hope that the power commander will be a cheap compromise.
Pictures of the mods
BTW. The link above has been broken for a while, but I'll leave it up just in case a miracle happ[ens and it returns.

posted by vxtbrit - Benelliforum ?? 2006
TNT "first run with mods"
The power commander has smoothed out all of the jerking and the "ruff" running at the low end. It’s so much smoother and pulls like a train, without hesitation from 2000 rpm. The devil can is sweet and without the baffle just quiet enough not to drive you crackers. Although the air temp was only about 12 deg the engine never went close to over heating.
First time I’ve had a long ride without the dreaded cutting out or hot starting problem. I am convinced that with the 16mm new cables and the pcIII those days have gone.