Norge Twin Spark Change

[draidt]

Now I've read the posts suggesting that you should be able to leave the airbox in place to change the inner spark plugs. However, I can't even see the right one, let alone get my hand in there or even my turned down socket, with the airbox in place. So, my question is what's the best way to remove the airbox. Will it come off along with the intake hoses, leaving them connected at the airbox, or is it best to leave the intake hoses connected to the throttle bodies and separate the hoses from the airbox?

As a side comment -- nothing seems to be engineered these days for access and ease of maintenance. I would think that the airbox could have been altered a little to allow the wiring harness to be moved away from the frame rail thereby exposing the top of the right cylinders inner plug. I guess with Cad all they care about is if they can cram everything in.

I see John beat me to it :mrgreen: , but since I had all ready typed this out Ill post anyway. BTW removing the whole air box is one of the most frustrating things you will ever do only a little less then installing it :woohoo:

No need to remove the air-box, the right one is hidden by a wiring cable that has to be moved slightly. it tight but doable. Just make sure you have the correct modified socket, a wobble extension also helps. If you need more room the front of the air-box is actually the breather box, it will come out separately from the main air box. remove 2 screws in back of it and all hoses and it will lift right out.

Suggestion; blow out the inner holes with compressed air before you remove the plugs, when the plugs are almost out, blow out again. Use liberal amount of anti seize on the new plugs and don't force them in as the angle is very deceiving, once started they should screw in easily.

 

[Brian UK]

I bought a 2007 demo this summer and now it's time to change the plugs. The owners manual makes a point to say the top/second plug must be done by a dealer and that both be done at the same time. What is the issue with the second plug and is there are procedure to follow? The manual is no help and Guzziology doesn't cover.
Thanks,
Ken

When it says both to be done at the same time, also note that the inner one is only changed every other outer plug change. In other words at half the frequency.
You may be making work which you don't need.

 

[nwrider]

Thanks for the suggestions -- and to look again. I finally realized that by disconnecting the electrical connector coming out of the harness just above the plug would allow access without removing the airbox. However, I'm going to get a spark plug boot pliar -- getting the boot off is one thing, getting it back on by hand, for me --- impossible.

On a related topic the torques specified for the plugs seems a bit high to me. 20 -30 Nm for the main plug 25 Nm = 18.4 lbs-ft while the inner plug shows 13 - 15 Nm at 14Nm= 10.3 lbs-ft I used 210 lbs-inch for the outer and 120 lbs-in for the inner.

Edit: It just occurred to me that since I used some anti-seize on the plug threads that the torque may have been affected. E.g. with no lube the friction coefficient would have been higher and the torque vaule would have been reached with less rotation. Thoughts?

 

[NeroGuzzi]

Thanks for the suggestions -- and to look again. I finally realized that by disconnecting the electrical connector coming out of the harness just above the plug would allow access without removing the airbox. However, I'm going to get a spark plug boot pliar -- getting the boot off is one thing, getting it back on by hand, for me --- impossible.

On a related topic the torques specified for the plugs seems a bit high to me. 20 -30 Nm for the main plug 25 Nm = 18.4 lbs-ft while the inner plug shows 13 - 15 Nm at 14Nm= 10.3 lbs-ft I used 210 lbs-inch for the outer and 120 lbs-in for the inner.

Edit: It just occurred to me that since I used some anti-seize on the plug threads that the torque may have been affected. E.g. with no lube the friction coefficient would have been higher and the torque vaule would have been reached with less rotation. Thoughts?

The only spark plug torque I have found is in the B11 owners manual (pg. 73), specifying 20Nm for the outer plugs. Where did you find a torque for the inner plugs?

Personally, I would not change a specified torque on a fastener due to lubrication. After all, most fasteners will have some form of lubricant on the threads. The grease on your fingers while handling the threads could be considered a lubricant. I have seen material, thread pitch/count, diameter, and type of fastener used as factors to calculate a torque value. I have not seen lubrication used as a factor. I would be interested in knowing if that is the case.

 

[nwrider]

The torque figures were contained in the Norge Service Manual on a PDF file that was available online through Aprilia/Piaggio's website in 2006/2007.

 

[Brian UK]

In 40 years of maintaining engines on all sorts of vehicles, I have never yet used a torque wrench on a spark plug. I have also never had one come loose, or stripped a thread. As long as you have a good sealing washer on the plug, all you need to do is make sure that this is properly seated, and nipped up with a small spanner.

 

[john zibell]

In 40 years of maintaining engines on all sorts of vehicles, I have never yet used a torque wrench on a spark plug. I have also never had one come loose, or stripped a thread. As long as you have a good sealing washer on the plug, all you need to do is make sure that this is properly seated, and nipped up with a small spanner.

Same here, you only have to crush the sealing washer a bit for it to be properly installed. I think they provide torque specifications for gorillas that have no wrench art capabilities to prevent damage.

 

[NeroGuzzi]

Same here, you only have to crush the sealing washer a bit for it to be properly installed.

Agreed. Most motorcycle applications do not need a torque wrench if there is good understanding of the fastener. Understanding the dynamics of tightening a spark plug with a crush washer and not needing a torque wrench is one of them. For situations where the fastener is not understood, a torque wrench and an appropriate torque specification would be safer.

I think they provide torque specifications for gorillas that have no wrench art capabilities to prevent damage.

I think torque specifications are specified to ensure the integrity of a fastener. Under-torquing can result in the fastener loosening. Over-torquing can result in a stripped or fatigued fastener. The latter being the scariest of the two because a fatigued fastener usually manifests itself with fractures that go unnoticed and therefore may let go unsuspectedly. With a stripped fastener, you know right away the fastener has lost integrity.

There are well-documented cases in aviation where under-torquing or over-torquing have resulted in a mishap. Granted, we are talking about motorcycles. I honestly have not done the research on motorcycles to find out if there are any relevant cases. However, I liken a wheel torque specification as one of those critical fasteners, if inappropriately torqued, can lead to a mishap. A calibrated elbow can not accurately distinguish between 70, 80 and 90Nm. Yet, 90Nm may be the point a fastener becomes fatigued. A single over-torque can be enough to weaken the integrity of a fastener. And an under torque of 70Nm may be enough for the fastener to vibrate loose at specific frequencies. So why take the chance? Confirm the torque is appropriate, and safely torque the fastener with a torque wrench.

MG has done a poor job in the quality assurance of their manuals. There are some inconsistencies in torque specifications and some ridiculous torque specifications. The recommended torque for the B11 CARC breather comes to mind. I believe it is grossly misprinted as 30Nm. By my observation, the manual inconsistencies and some poor specifications have led to a lack of confidence in the recommended torques. That is understandable. But the answer is not, "throw away your torque wrench!" That is neither prudent nor universally applicable.

Facilitating torque questions is a better answer. Guzzi owners, suffering through poor dealer support in some areas, and wrenching on their own bikes, come to this technical forum for a recommended torque. Facilitate the question and recommend a torque or better suited method. NOT knowing if the MG recommended torque is appropriate or if another method is more applicable is a scarier proposition. A reluctance to ask a torque question could result in an inappropriately tightened fastener, or worse, an unsafe fastener. Facilitate the question because under or over-torquing a fastener is an important enough subject to post on a MG technical forum to get some constructive feedback from Guzzi-knowledgeable people.

 

[Brian UK]

Well we were talking about spark plugs, and in that respect, I agree with every word John wrote.

You also demonstrate the danger of blindly following a figure printed, as there may be mistakes. This is even more likely if you have to convert from one measurement system to another.
In critical areas like head bolts, then a torque wrench is invaluable of course, particularly with alloy castings

 

[john zibell]

Well we were talking about spark plugs, and in that respect, I agree with every word John wrote.

You also demonstrate the danger of blindly following a figure printed, as there may be mistakes. This is even more likely if you have to convert from one measurement system to another.
In critical areas like head bolts, then a torque wrench is invaluable of course, particularly with alloy castings

Thanks Brian,

I actually have several torque wrenches that I use for items where the correct torques are critical, but on a motorcycle, there aren't many.