961 - Heavy Misfire - the full kangaroo

Hi Peeps,

My 2011 961 (1500 miles on the clock) has developed a very nasty misfire. It began to get this bad habit about 3 or 4 days ago. It grew worse and worse and now it is there all the time (making it easier to track down I hope).

Now, when I say misfire, I don't mean the usual flutter and splutter of a 961, I mean jerk you right out the saddle and throw you in a ditch kangaroo style with grind to a halt thrown in for good measure. NB There are no backfires at all. Just missing fires!

Sometimes I have to turn the ignition switch off and on again before the starter will operate (might be a clue). Sometimes the starter will operate without doing so.

What have I done to help myself:

- Took the side stand out of the circuit with a jumper lead - no difference;
- Checked the size of the spark from the coil (10mm easily). A blue crackly purple spark;
- Checked all connectors at engine level in all the oil, water, salt and dirt;
- Checked the right hand handlebar switch gear for muck or corrosion (all immaculate);
- Checked the tilt switch - fine;
- Checked all the wiring under the cowl (immaculate);
- Blew the fuel tank vents through - no obstruction;
- Opened the tank filler to let air in when misfiring - no change;
- changed the spark plugs;
- Cut 20mm off the plug leads and made sure that they sit properly and fully on the spark plug. There was a little "bounce". (I think that reduced the kangaroo but didn't stop the soft missing beats );

So, now I am into the "what do I do next" stage ? Any ideas?

Is it your experience that a Norton dealer is the best place to trailer the bike to. If they are going to just swap parts in until the misfire disappears I can do that without £130 per hour labour.

You help would be much appreciated.

Terry

I don't have a modern norton, but occasionally someone gets this on the old version where it just shuts off, then magically restarts like nothing is wrong, and it can be a worn out ignition switch. The other thing that comes to mind is a skinned wire somewhere grounding out against the frame, or in the case of the old bikes, somewhere inside the headlight shell...

Other than that, I would always change the spark plugs first, because if the insulator cracks up inside the plug, it may test fire when held against the head, but inside the cylinder that spark may arc up inside the plug's body at the insulator crack occasionally where it won't ignite the fuel...

The bike is like pristine. Only done about 1500 miles so I hope the ignition switch is a low-probability item. I went over all the visible wiring and sprayed switch cleaner into the two plug halves to clean the connections.
I had changed the spark plugs already. NB I updated my first post as I forgot to say that. whoops.
Many thanks.

Tank off and check battery connections, wiring sockets and relay are fully home in the sockets?

Hi Mx - done all that. Many thanks.

Terry

Sometimes I have to turn the ignition switch off and on again before the starter will operate (might be a clue). Sometimes the starter will operate without doing so.

are you saying the starter is operating without pressing button ??

Is the starter operating while you are riding ? that will cause some serious damage !!!
to you and the bike,
I would definitely get look at by a dealer .

cheers

Paul

Water got in the tank? Ethanol will absorb water from the air, especially from a part filled tank left over winter, if you are running out of obvious ideas worth flushing tank and see what comes out.

The last time I had a bike that kangaroo'd like that it was water in the bottom of the carbs.

It may not be a bad idea to take it to Norton or a dealer . When you said earlier that you could swap out parts just like they can . The problem is that you have to buy all these parts to try in their place. Norton or a dealer may be able to plug in to the ECU and see what's amiss . Sometimes it's worth paying for help. My tilt switch caused my engine to cut off suddenly when I was riding. Also , don't forget the fuse box , those relays may come out or a fuse can crack !

With 1500 miles in 8 years (187.5 per year), Terry has probably passed his test on a puch maxi and then is just a bit nervous with the clutch on big boys bike. Cue the backlash from Terry

Welshmen . . . I just bought the bike three weeks ago. Now you feel silly?
Anyway what is wrong with my Puch Maxi..
Have fresh fuel. Have checked tilt switch and relays. I took everything out under the rear cowl and checked and cleaned all contacts. I didn’t change the tilt switch but it has normal behavior when tested with a dvm.
Getting to the stage when I rip down the fuel intake and get the injectors scrubbed unless I can buy an injector cleaner. Seen them on YouTube. They exercise the injector electrically while you squirt injector cleaner through. I heard tales of the manifold lining coming off and clogging injectors on 961s. Wish the Norton dealer were closer . . .

Yes , I have heard about that too. The billet fuel rail from Norton is the way to go now like the newer bikes have. Are both cylinders cutting out same time ? Or can you narrow to a cylinder ?

TerryW said:

I heard tales of the manifold lining coming off and clogging injectors on 961s. . . .

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Thats a new one on me.

Where did you hear these tales?

I don’t recall it being discussed before on here, and we have a lot of discussion about 961 niggles!

Anyone else seen this?

Fast Eddie said:

Anyone else seen this?

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I mentioned it in a post last month, although it was part of a list of issues I had experienced, so easily missed. I hadn't heard of anyone else reporting it. It had happened at around 1800 miles and the symptom was firing on one cylinder only. It wasn't intermittent. The factory replaced the fuel rail and told me that the injector was blocked due to something flaking off inside.

The reason we found the Bosch coil was because my dads bike did that on the way back from Texas to Niagara Falls. He at first thought it was weather related. Found it was the coil. Got another norton one and same thing a year later. Found a match being the bosch coil and found from the bosch dealer the norton ones are fake knock offs of another bosch coil which is why it took so long to figure out. Worth looking into a bosch coil. Part number in my manuals.

Fast Eddie said:

Thats a new one on me.

Where did you hear these tales?

I don’t recall it being discussed before on here, and we have a lot of discussion about 961 niggles!

Anyone else seen this?

Click to expand...

These are not tales . It has not happened to me (yet) . I have purchased a set of new injectors and a billet fuel rail from Norton already. The prices are reasonable and worth the investment in my view. FE , you should be good because you have the billet rail from New . I wonder what Norton's position is on filter screen installation like iwilson has done ? This may prevent an immediate clogging from the flakes or rust or whatever it is. Can Rob tell us whether or not Norton recommend the use of these injector screens for our bikes ? Also , it may be batches of the old style rail which are affected. And can/will Norton provide a spare part number for the screens if they think this is a good idea ? Thanks Rob !

Texas to Niagra falls Rich? That’s a good ride!!

I think we should point out here that whilst anyone with an older 961 may have the knock off coil issue, the newer bikes use the genuine Bosch items.

TonyA said:

These are not tales . It has not happened to me (yet) . I have purchased a set of new injectors and a billet fuel rail from Norton already. The prices are reasonable and worth the investment in my view. FE , you should be good because you have the billet rail from New . I wonder what Norton's position is on filter screen installation like iwilson has done ? This may prevent an immediate clogging from the flakes or rust or whatever it is. Can Rob tell us whether or not Norton recommend the use of these injector screens for our bikes ? Also , it may be batches of the old style rail which are affected. And can/will Norton provide a spare part number for the screens if they think this is a good idea ? Thanks Rob !

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I wasn’t disputin’ Tony, just saying I’d not heard of it.

It’s interesting though, is it another niggle ‘unique’ to the 961 and not shared with the other tens of millions of fuel injected engine currently out there?

Is it related to running the injectors sans filters? Would be very interesting indeed to know why Norton feel it necessary to run the injectors such...

Fast Eddie said:

Is it related to running the injectors sans filters? Would be very interesting indeed to know why Norton feel it necessary to run the injectors such...

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Indeed.

Fast Eddie said:

Texas to Niagra falls Rich? That’s a good ride!!

I think we should point out here that whilst anyone with an older 961 may have the knock off coil issue, the newer bikes use the genuine Bosch items.

Click to expand...

My dad rode to texas and back TO NF on the 961 SE and then to Oregon then BC and back through Canada the following year on the 961. Then him and I rode to North Carolina each on 961’s with back packs tented for a week at the INOA2015 ashville. Thats when he had his accident. Lookup flickr.com/one07. Albums.