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Discussion Starter · #1 · (Edited)
Following up on a post I placed about 3 weeks ago.... I started the bike today and let it run for a bit to warm up.... no problems.... all of a sudden the idle went all "fluffy" and the rev counter needle fluctuated up and down between 1000 - 1500 RPM. I opened the throttle a bit and it went away but once I let it drop back to idle it started to go "fluffy" again after about 10 seconds. Any thoughts from anyone on what it could be....? I'm wondering if the it's the coils or ECU messing about....? I've had the bike for over a year now and it's just started doing it. :confused:
 

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Surge at idle?

Mike, I just read the following on the Tuneboy web page

Idle fuel trim is a very important adjustment for all bikes that do not have an O2 sensor. This adjustment being incorrectly set is the cause of most of the surge problems at low revs.

I suggest that you set this value by "seat of the pants" testing.
Does that sound like what's happening to yours?
Read on ....
Tuneboy Tutorial
 

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Discussion Starter · #6 · (Edited)
Engenia, It's not really a surge as such....after speaking to Russ on Thursday he reckons it may be related to the valve clearances as he has had a couple of bikes with the same problem whose clearances were on the tight side. After he had adjusted them the problem was gone....I'm sure Russ can put more 'meat on the bones'....my bike is due to have the clearances checked in about 500 miles but it might be sooner now....!
 

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Discussion Starter · #7 ·
Fluffy Idle Update

Well I took the bike for a long ride today, the first since putting it to bed for the winter and it rode fine....so still not sure what caused the original problem....! :confused:
 

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Fluffy idle

Hi Mike,
I don't know much at all..... but what map do you have installed on your Nelli? If ambient temp is a factor, you have let it hibernate over winter, it could be a rich fuel map that is over fuelling it in higher ambient temperatures. I organised a remapping on mine and a mates bike and they have improved no end. Did you disconnect the battery for an extended period of time when you did the core plugs or parked it up for the winter break? This can cause some dramas with the "keep alive memory" Valve clearances sounds doubtfull, if tight, it will misfire cold and maybe behave hot, if loose, will rattle cold and improve hot unless its excessive. If its too tight when warm, thats valve recession, and also doubtfull.
As I said, I don't know much, but I'd fire it up, keep it idling or at mid revs until the fans cycle twice, make sure it idles and shoot it around the block gently until or if it runs right...... just my opinion mate.
Cheers, Dave
 

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Discussion Starter · #9 · (Edited)
Fluffy Idle

Dave, I've had the bike on an Optimate III over winter and didn't disconnect the battery when doing the core plug the other day. I am currently running the BE.3029.HEX map supplied by TEXA for the AXONE 2000 'Game Boy' which came out at the beginning of August 2006. I had this map put on when the clutch basket was replaced as I still had the original map (3020 stamped on the ECU) on the bike. It seemed smoother and nowhere near as rich (end of the can is a nice light brown colour now as opposed to black) with this map loaded. When I took the bike out the other day it was fine - no flat spots or hesitation in the rev range....however when I started it up in the garage after replacing the plug and let it warm up it started messing about again. When I increased the revs slightly it was gone and when I let it drop back to idle it was okay for about 20 seconds before it started again. The very first time this happened was when I got the bike up to a high enough temperature for the fans to start running....ever since then it starts doing it more or less as soon as it comes off of fast idle. I must admit that one of my thoughts was to get the map reloaded into the ECU incase it has somehow got corrupted or something.....? :confused:
 

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Fluffy idle

Hi Mike,
I would recommend doing a "quick" check to see if all the earth wires are still connected under the tank. I'd assume that you had to pull the tank and fairing to replace the plug (unless you are Houdini). It sounds exactly like what happened to my mates bike. The earth wire is common for the throttle position switch, coolant temp switch and one other sensor which escapes me at the moment. We had no earth to the throttle position sensor, the tank had been yanked off in the past and broken the wire, we resoldered and it was a new bike. Might not be the same issue but the symptoms are exactly the same. Hope this helps, Cheers, Dave
 

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Mike i'm a TNT man but the tornado engines are virtually the same, 2 things,
1 the Benelli is one of the worst bikes to start and let warm up on the stand the temp rises to quickly in localised areas allowing the engine to expand at different rates which could result in distortion/leaks, its much better to start the bike put it in gear and ride off straight away (not thrashing it until its warm) :)
2 the air temp sensor is not the best on the benelli's the sensor is positioned close to the top of the engine and without air cooling it (created when the bike is moving) it can be fooled into thinking the ambient air is higher than it really is, (via radiant heat from the engine) this in turn could make the ecu modify the fuelling which could cause the symptoms you describe...just my 2 pennys worth to try and help.
Terry
 

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Discussion Starter · #12 ·
Fluffy Idle

Terry and Dave thanks for your comments....Dave with regards to tank removal I must be Houdini as it never came off to do the core plug. I just took off the side fairing panel and air ducting to the radiator and that was enough to give good access. Will lift the tank in the next couple of days and have a look to see if I can find anything....will let you know.
 

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Discussion Starter · #13 · (Edited)
Fluffy Idle - Still Fluffy

Dave, Going to have the tank off the bike tomorrow....when lifted are the earth wires apparent (Havn't lifted the tank before) in a group or run to each sensor and did you have to remove the air box. I know the TPS is on the right side of the throttle housing and was going to have a general nose about to see if there is anything obvious....
 

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Discussion Starter · #14 · (Edited)
Fluffy Idle - Could be coils or plugs....?

I've had the tank off today and removed the top of the airbox to check all the sensor connectors and everything looks fine. On listening to the bike when stripped down it sounds more and more like it starts to run on two cylinders at idle....On speaking to a few dealers (As I am running out of ideas) two said it could be that the coils or plugs are the problem and that I could be getting a weak spark (Plugs could be fouled) when the bike is at idle - they could not explain why the bike was fine when being ridden. Any more thoughts from anyone would be appreciated especially anyone who has had problems with the coils or spark plugs....
 

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Possible plugs!

:p

You could have a plug breaking down at idle which clears as the revs are raised, I had one once. Spark plugs can break down as soon as they are fired up.
I don't think we have heard of any coil failures yet (I could be wrong!)
 

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coil failure?

Lloyd, I've got a dead coil here from Al (who else!), & I know of one dying in Melbourne. So they do fail, but it's not common.
 

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coil failure

It does happen, bike was in for a service at KJM and one of my coil sticks had to be replaced as it was about to fail, Glen said that this was due to the fact that the coils were not sealed coming out of the factory on the original tre's and this leads to water ingress and the body of the coil corrodes and allows arcing. This problem was causing the bike to almost stall as I was changing down. The middle coil is the worst culprit as it will pick up extra moisture and crap as it is in the firing line of the front wheel.
 

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Discussion Starter · #18 ·
Fluffy Idle - New Plugs

Thanks for the comments guys....I'm going to pick up some shiny new NGK CR9E's on Tuesday and then strip the bike and replace the old plugs. Hopefully that will cure the problem....wish me luck....!
 

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Ngk

Lloyd,
never mind. I thought I was wrong once, but it turned out I was mistaken.:D

Mike,
not sure if it is the same in your part of the world, but here, NGK doesn't supply caps with the CR9E's, & they are needed to get a good connection. Without them, you'll have 2 sparks jumping. One outside the engine, & one inside.
So make sure you get a set of caps as well.
 
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