1957 M16 not running properly

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McMaz
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Re: 1957 M16 not running properly

Post by McMaz »

Andy, it may be worth checking that there isn't an air leak somewhere – the face where the carb meets the cylinder can sometimes be slightly warped through over tightening. The other thing that comes to mind is that the float height may be wrong and therefore giving an incorrect fuel level in the carb. On amals the pip on the float chamber cover indicates the correct fuel level – see how to check it, along with a few other tips, here: http://www.whfolk.co.uk/REOCHUMBER/Arti ... nobloc.htm
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Janet
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Re: 1957 M16 not running properly

Post by Janet »

Caveat: I know nothing but............

Doesn't flames from the carb suggest the inlet valve may be open when the plug is sparking?
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LynP
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Re: 1957 M16 not running properly

Post by LynP »

I know that the carb is still probably the issue, but is the advance and retard unit moving freely? I ask this because of the spitting back. May help, LynP
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clanger9
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Re: 1957 M16 not running properly

Post by clanger9 »

Janet wrote:Doesn't flames from the carb suggest the inlet valve may be open when the plug is sparking?
It can also be caused by liquid fuel/droplets - which can happen if the idle jet isn't atomising the fuel properly (or if the inlet manifold is cold).
My CSR hasn't got a choke, so it spits nice flames from the carb when started from cold... :twisted:
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Plugsnpoints
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Re: 1957 M16 not running properly

Post by Plugsnpoints »

I took the advance/retard unit off yesterday and it's free, especially after lubricating it, I remember from experience with my Enfield 250 many year ago, when the bob weights stuck wide open. I retimed it after that.

I'm still puzzled, but will get back to it tomorrow :headbang:


Andy :lol:
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clanger9
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Re: 1957 M16 not running properly

Post by clanger9 »

As others have said:
1. Check the float height
2. Check the idle jet is clear
3. Check it's got the right slide cutaway
Any of the above can produce the symptoms you describe...

Good luck!
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Re: 1957 M16 not running properly

Post by Plugsnpoints »

I must admit I am not sure how to check the float height. If so how do I alter it if it's not correct as there's not anything to bend? Thanks :)
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clanger9
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Re: 1957 M16 not running properly

Post by clanger9 »

Aha.

You mentioned you replaced the float valve? It's a good idea to check the float level after doing that...
- Take off the idle jet cover nut
- Push a length of clear pipe over the idle jet
- Hold the pipe against the float chamber body

The fuel level should line up exactly with the little "pip" on the float chamber cover. If it's wrong, you'll need to add (or remove) a washer under the fuel inlet union.
There's a better set of instructions in this thread: https://www.triumphrat.net/classic-vint ... -carb.html
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Re: 1957 M16 not running properly

Post by Plugsnpoints »

Thanks for that clanger9. That makes sense if it's flooding it or starving it. A manometer! I'll have a try with that soon. :)
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Re: 1957 M16 not running properly

Post by Plugsnpoints »

Well, after checking the ignition timing once again-it's 1/2" BTDC fully advanced. Points gap 15 thou.


I have replaced the float needle, and put a better seat in, and still it decides to stick and p petrol everywhere! I checked the float, and when I lift it gently the fuel shuts off as it should. There doesn't appear to be a pimple on the float chamber cover to check the level.


I have decided to leave it for now as it's getting frustrating now. It starts easily but doesn't want to rev and the plug is soaking wet and sooty (not the bear with a wand!).


The main jet is a 105 if I remember correctly.

I need a lie down now! :o
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