hi My bike started reasonably well and was left running for 5 minutes to warm up when I tried to take away up a slight hill from my house the bike back fired and lost power and stopped despite my attempts to keep it going. My thoughts are that the carbs my need to be cleaned out. be grateful for any help.
power loss
- Thread starter Jk34
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I'd simply pull the spark plugs and look at them to see if they are possibly sooty back. I would not let my Crazy "warm up " for 5 minutes , I'm assuming you had the choke on ?
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1st thing that Always Occurs to my Cdo mind now is electronic Trigger Wires breaking up inside insulation and next thing is coil wires attachments then on down the loom before I'd check carbs taps on or water in bowl or loose fasteners etc. Gremlin bells don't seem to work on smooth Cdo's so rabbit foots works better for mine, once i get the right color they like.
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if you are using the Amal choke system to start your bike, know that it enriches the mixture by decreasing the amount of air, this can and does quickly foul your spark plugs
many of us do not bother using the Amal choke, we just tickle until gas comes and out and kick and then hold the idle with throttle hand around 1300rpm or so while sitting on the bike in full ride away gear, let it idle like this with no choke about one minute and then take off, it will quickly warm and clear the leanness hickups
as suggested, pull the plugs and clean em good or replace if blackened and don't use the choke again, but if you
insist then use it only to start and immediately lift the choke slide and keep it going by hand
many of us do not bother using the Amal choke, we just tickle until gas comes and out and kick and then hold the idle with throttle hand around 1300rpm or so while sitting on the bike in full ride away gear, let it idle like this with no choke about one minute and then take off, it will quickly warm and clear the leanness hickups
as suggested, pull the plugs and clean em good or replace if blackened and don't use the choke again, but if you
insist then use it only to start and immediately lift the choke slide and keep it going by hand
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ABOUT SPARK PLUGS... I always have plenty of NEW spare spark plugs. Nothing beats new plugs....no matter how well they are cleaned they never perform as well. If the bike gives any problem starting it is probably from a plug that has been in too long. It is the cheapest and easiest way to keep it running well. I do not bother trying to get the last mile out of each plug. THEY ARE EXPENDABLE!!
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AMEND to trying new plugs even if used ones still perfectly fine they do tend to fail to fire after engine self stalls for various reasons so saves frustration to eliminate that right off the bat BUTT I've had new plugs fail to fire driving me crazy till dug into trash for the crappy plugs to get back one kick start of nice ride day. Once a plug type decided on best to get a V8 pack - wasteful as that may seem at the time, the whole hobby is wasteful of time and money so only the fleeting pleasures/successes of fully fettered Cdo makes any of this worth it.
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I must be a lucky shit then. Haven't looked at my plugs since the rally in Feb. last year, when I had to fix the broken wires on my Boyer. [ they were over 2 years old then ] Thing is, I get all my gear on, start the bike first kick, then ride it. It warms up on the road. Never believed in pissing round with a Norton.
Dereck
Dereck
Hi I have had the bike for a year and a half. The bike has twin Amals and Boyer ignition set up. Befor i started the bike i took the plugs out and gave them a clean, they were sooty black from the previous ride of about 1 1/2 hours. So i weakened the mixture by 1/8 of a turn on the screw. The bike started up fine with choke but backed it off when the barrels felt warm, i checked the oil level , reved the bike a couple of times befor i set off all seemed well. There is a incline in the road outside my house and as i set off up it in 1st the bike lost power back fired and came to a stop. I started it again but power loss was still there. hope this gives enough info
concours
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Jk34 said:
Ok, sooty plugs. What's the smell? Like a worn out Chevy?(Vauxhall?) or like a lawnmower with the choke on? Stick your finger in the exhaust and swipe, dry black soot? Oily like a two stroke?
Get a compression test done and report back with results.
In the past, when had the plugs out, what were they like? Always dark? Somewhat sooty? Or clean and light?
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Carbs are toast. Remove air filter. Reach in with 2 fingers and try to wiggle slide back n' forth ,wiggle = toast. :|
ashman
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You can have worn slides and the bike will still run, if your plugs are sooty black after a ride of 1 1/2 hrs then maybe that is telling you its running a bit rich, maybe your jets and needles need replacing, but just loosing power like that could be a few things to look for, you just have to trouble shoot everything a broken wire in your Boyar, the only way to find out is to check everything out that makes it goes bang.
I have been running my spark plugs now for over 5 years and they still look as good as the day they went in, but then Joe Hunt maggies are like that and I still run the N7Y Champions, but plugs do fail when running sooty.
Ashley
I have been running my spark plugs now for over 5 years and they still look as good as the day they went in, but then Joe Hunt maggies are like that and I still run the N7Y Champions, but plugs do fail when running sooty.
Ashley
concours
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Jk34 said:
Worn slide: Erratic idle, inability to tune idle/low speed tip in. A rich idle mixture helps to mask the symptom... a little.
Worn needle jet and/or jet needle will be rich mid range.
I still had nice clean plugs with very worn slides and somewhat worn needle jets.
It makes sense that the worn slide would give an erratic mixture, but on the lean side. The worn needle set makes things too rich. I found that with my worn out carbs, the worn needle more than counteracted any leaning effect from the worn slides. The bike started running a little too rich, then in just a few thousand miles quickly went crazy rich, down to about 25 MPG from 55 MPG. After fitting new Amal Priemieres from Jerry, with all the same jetting as the worn carbs, the mileage was back to 55-60 Imperial. Also pulling power in top a low throttle openings was restored, ie torque.
Glen
Glen
batrider
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Needle jets are sized by actual diameter so a 106 needle jet should be .106" and a 107 is .107". So only .001" wear puts you in the next size richer jet. As far as I know there is 105, 106 and 107 as the choices and there is a big difference between them. The needle jet takes a real beating with the intake pulses and being sawed by the needle. If it stutters while driving down Main St. in second gear at constant speed then I would look at needles and needle jets. I change my needles and needle jets every 4-5000 miles when I start noticing it! I've had slide wear before and it didn't really make much difference. Maybe the idle was a little more finicky.
The needle and needle jet situation can get more complicated because sometimes the 106 jets are not exactly .106" when new. My bike would probably like a .1055" to start off with. Much written on this subtopic in earlier threads.
Not sure I would call this particular thing power loss - just running like shit at constant speed. No lack of power when cranked on.
The needle and needle jet situation can get more complicated because sometimes the 106 jets are not exactly .106" when new. My bike would probably like a .1055" to start off with. Much written on this subtopic in earlier threads.
Not sure I would call this particular thing power loss - just running like shit at constant speed. No lack of power when cranked on.
Hi I tried to start the bike up without using the choke but with no luck it was as dead as a doornail. Using choke it started and I shut it off as soon as it let me. Bike was ticking over ok but back fired when opened up to 3500 to 4000 revs. Went out for a ride and the bike settled down apart from the odd back fire. When I got back I removed plugs the right hand cylinder was light grey the left hand sooty black so have weakened that one a touch. Also went up a steep hill bike pulled well.
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