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Post by ilovenxstage on Jul 4, 2013 8:20:56 GMT -5
I've been fighting like mad to get my "new" '78 NC50 to run right. The idle jet was clogged, and I worked my bum off to get that unclogged. It's still not running very well, but it's a little better. It's idling ok now, but when I roll the bike off the centre stand, or jolt it in any other way, it wants to die. If I come to a stop really fast, it bogs down and I have to give it throttle till it comes back up to idle speed and smooths out. I'm new to working with two strokes, so any help would be great. Oh, I'm also having problems with the bike cutting out it mid throttle. It'll run at low throttle and WOT, but it cuts out in between.
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Post by scootnwinn on Jul 4, 2013 8:41:57 GMT -5
Sounds like something is loose. Can you post pics? How many miles on it? DId you clean the whole carb or just the idle jet? Is the fuel fresh? Did you replace the spark plug?
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Post by Deleted on Jul 4, 2013 10:10:02 GMT -5
Cdi connection?
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Post by ilovenxstage on Jul 4, 2013 10:26:40 GMT -5
It has point ignition so there's no CDI. It has 5200 miles on it. It does have fresh fuel and oil. The plug is not new but it has a strong blue spark. I did clean the entire carb.
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Post by scootnwinn on Jul 4, 2013 10:31:21 GMT -5
Make sure the carb is firmly connected. Check for any other place the system could be disrupted. Make sure your main needle valve is properly installed and that it isn't loose
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Post by alleyoop on Jul 4, 2013 21:44:43 GMT -5
Sounds more like the CARB BOWL is not filling up enough and the fuel level is low so any jolts the fuel slashs around and uncovers the jet leaving it only to suck air.
Alleyoop
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Post by ilovenxstage on Jul 4, 2013 22:29:54 GMT -5
I'm also having problems with the float bowl leaking out the overflow. I've cleaned the carb several times and I don't think the float is sticking. It doesn't seem to overflow when the bike is running though. I'm starting to think I might be better off upgrading to a new carburetor, although I don't know what, if any aftermarket carbs will bolt right up to an NC50 intake. I'd like to be able to replace the jets because of the big bore kit and high flow exhaust. The stock carb has non replaceable press-in jets.
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Post by ramblinman on Jul 4, 2013 22:54:17 GMT -5
I might be better off upgrading to a new carburetor, although I don't know what, if any aftermarket carbs will bolt right up to an NC50 intake. a quick search didn't turn up any good news. those carbs are expensive and rare. is it possible to modify the intake manifold so it would fit a cheap replacement carb? i would try to do that before i paid $150 for an old carb. |
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Post by alleyoop on Jul 4, 2013 23:10:32 GMT -5
The carbs are simple you just have to clean them out good and adjust the float. The adjustments are a little finicky I know I fixed one for my neighbor that was sitting in a shed for over 20 years.
Alleyoop
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Post by ilovenxstage on Jul 6, 2013 20:49:15 GMT -5
It's running a lot better now. It's not cutting out, the idle is good, and the carb is no longer flooding. The guy I got it from is still going to give me a new carburetor and a fuel tank and petcock that's in much better condition. He's even going to strip and repaint the fuel tank and make new decals for it, all for free. The carb is not from an NC50, but he has also made a custom intake manifold that the new carb will bolt right up to.
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Post by jerseyboy on Jul 6, 2013 20:52:02 GMT -5
[replyingto=ilovenxstage]ilovenxstage[/replyingto]Make sure your intake and carb ports/gaskets all match,also intake and motor or it wont run right...
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Post by alleyoop on Jul 6, 2013 21:23:17 GMT -5
Problem is the motors on these things do not have a valve seat, the head is just cut out to fit the valve head. If he did drop a valve it can be checked by taking the vlave cover off and rotate the motor over by hand and see if the stem on both come all the way up. If one does not then the valve stem is bent but I do not think so the motor runs pretty good if a valve was that bad it would not run so good.
Alleyoop
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Post by scootnwinn on Jul 6, 2013 21:36:54 GMT -5
It's a 2 stroke which valve cover should he remove to check the valve. Are you talking about the fuel valve?  these motors have no valves. Don't worry about dropping them Honda did it at the factory |
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Post by alleyoop on Jul 6, 2013 22:02:38 GMT -5
AH, that is correct this is a little 2 banger
The only valve is the reed
Alleyoop
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..BAD TO THE BONE..
