Running problem

BionicDan

Joined
Sep 2, 2015
Messages
53
Maybe someone could shed some light..?

A few weeks ago I was out one - pretty chilly - evening (ironically enough, I was on my way to my "Basic Motorcycle Maintenance and Repair" evening course, which I've not long started).

On the way to my destination (about 25 miles away), my Norton was just slightly shuddering and losing power with each shudder. It was almost imperceptible... just slight, and so I ignored it. Anyway, later that evening on my way home, the problem got really bad and I was concerned I might not make it home (that's how bad it got). I persevered although every time I had to stop (traffic lights, etc) it would cut out if I didn't keep revving.

I arrived back in the city and, a few miles from home, I was again stopped at traffic lights. This time, I thought, I'd give it some really high revs. From that point on, everything seemed fine. It ran ok. Now, I've not taken the 'bike out again since but intend to this weekend.

Anyone have any input on possible reasons / answers ?

Dan
8)
 
The bikes come with really cold plugs. which may foul if the bike is ridden very slowly especially in cold weather.
 
Hi,

On what should have been tick-over, there was no tick-over. ie. if I released the revs to resting (tick-over) it would cut out, so I had to make sure and keep up the revs when stopped. There was one point at which I did let it go as I stopped and it did cut out. I was afraid it might not start again but luckily enough it did start again fairly easily.

The biggest problem was the shuddering/pulling back with simultaneous drop in power while actually riding. It was a really marked intermittent jerking back with power-loss. I seem to remember (but am not totally sure) that the problem was mostly prevalent at slower speeds.

As far as the plugs are concerned, they were replaced with brand new ones just after I bought the bike in April this year 2015.

D
 
BionicDan said:
Hi,



As far as the plugs are concerned, they were replaced with brand new ones just after I bought the bike in April this year 2015.

D
Click to expand...

If the plugs were replaced with the stock ones my statement still stands and revving ( clearing it out ) would be consistent with this. What year is your bike, how many miles, stock or modified?
 
Check if one or both of the rubber caps situated between the injectors is missing... If you don't know which ones I mean I will try to send you a picture.
Cheers, Raphi
 
Raphi said:
Check if one or both of the rubber caps situated between the injectors is missing... If you don't know which ones I mean I will try to send you a picture.
Cheers, Raphi
Click to expand...


Check your Exhaust Header Nuts too. Leak could cause rough running.

My dad had a similar problem when the bike was new. Ended up the vent to the gas tank was too tight and zip-tied shut. So as the fuel was being used the pump had a harder time getting fuel to the engine. If found the pinched vent line and put on a new zip tie. Solved the issue but not really sure if that was it or bad gas or just a hiccup. Also, a tip is not to touch your throttle when starting the bike. It will sometimes throw the mixture off as the sensors reset with the key being turned on. Call me crazy but starting the bike without touching the throttle made a world of difference on my bike and my dads bike. More consistent running. Please share once you solve it.
 
Sounds similar to my last few days of riding to break in the bike. I picked up '14 CR stock with 6 miles. Rode 100 miles in two days. My bike also cuts off when standing at a light. It's odd that I have to rev waiting for the light to change. :x in fact the bike cut off while I was riding...got me little freaked out. Thank God the traffic was light and not that many cars. I had to restart while the bike was cruising.
 
Your set screw on the right side of the throttle bodies needs adjusting. Turn it CW 1/4turn. Ride and repeat till problem ceases. Mileage will help
There are several threads here on this problem.
 
Hi Guys,

Please don't adjust your throttle tick over screw as it affects the fuelling (basically the ECU doesn't know you have changed the throttle and therefore doesn't account for the extra air) and can cause the bike to run lean. Dallas Norton, if you drop me a PM I will link you up with a dealer who should be able to cure the issue you are having.

Kind Regards

Simon
 
NortonFactoryUK said:
Hi Guys,

Please don't adjust your throttle tick over screw as it affects the fuelling (basically the ECU doesn't know you have changed the throttle and therefore doesn't account for the extra air) and can cause the bike to run lean. Dallas Norton, if you drop me a PM I will link you up with a dealer who should be able to cure the issue you are having.

Kind Regards

Simon
Click to expand...

Appreciate it Simon. I already got in touch with RPM guys and they are on top of it. They offered to come and pick up the bike but I told him I wanted to ride little more to see if the problem goes away (didn't go away).
 
Hi Dan
Here come the promised pics of the cap and situation where you can find respectively feel for it with your finger, because it is hard to see the rubber caps.
I had once one of them missing and at least at tick-over the engine was not running properly due to false air sucked in...
Running problem

Running problem

Running problem


You have to look for the caps behind the grey injector bodies on either side.
Cheers and good luck, Raphi
 
THANKS for that, Raphi!!!
In fact THANKS to everyone.

I'm going to check out all the possibilities over the weekend, although the problem is that the last time I was out, the problem cleared after blasting out some high revs while sitting at traffic lights. So, how will I know if any of the possible problems given is/are the actual source. It may well be running smoothly now anyway.

One thought...
If, as was suggested, it's the plugs fouling up... there must surely be a reason why this is happening, no?

On another note, I can't remember who said but someone once told me I should let the 'bike run for a while first, before setting off. I haven't been doing this. Could this be a factor too?

Thanks again.

D
 
If the problem cleared after a few revs its not the caps. I always let the bike warm while I suit up but that wouldn't do it either1
The plugs are CR9EV, a very cold plug suitable for racing applications. Several members here have reported fouling type issues when riding very slowly or low revs, especially in cold weather!
 
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