[AT] Super M hard to start

[Thomas Martin]

Actually it isn't. As the throttle is engine side of the main jet, it can't induce a vacuum that will affect the main jet.

Whereas a choke can close air to the engine, thus creating a vacuum which will draw fuel through the main jet.


Tom

> On 09 February 2020 at 08:31 Ron Cook <ron at lakeport-1.com> wrote:
> 
> 
>     A closed throttle is essentially a choke.  We are not talking an injected engine here.
> 
>     Ron
> 
>     On 2/8/2020 12:37 PM, Dean Vinson wrote:
> 
>         > > 
> >         Thanks, everyone.  I don’t know about the timing, will have to look into it.  Gasoline in the tractor is pretty fresh… it gets used at least weekly.   Freeze plugs appear to be good.  :)
> > 
> >          
> > 
> >         I didn’t start the tractor this morning but it looked nice with a little snow on it.
> > 
> >          
> > 
> >         Dean Vinson
> > 
> >         Saint Paris, Ohio
> > 
> >          
> > 
> >          
> > 
> >         From: AT [mailto:at-bounces at lists.antique-tractor.com] On Behalf Of Dean Vinson
> >         Sent: Wednesday, February 5, 2020 8:29 PM
> >         To: 'Antique Tractor Email Discussion Group' <at at lists.antique-tractor.com> mailto:at at lists.antique-tractor.com
> >         Subject: [AT] Super M hard to start
> > 
> >          
> > 
> >         My Super M is hard to start in cold weather.   It always does start, eventually, but if the weather is cold it’ll take maybe five or six or eight attempts, with each one resulting in a few pops or a second or two of running before it dies.   I always think I just need to find the right amount of choke vs throttle, but I don’t know whether I’m really finding it or whether the engine just gets warmed up enough by the repeated attempts that finally it settles down and is just plain ready to start.   In warm weather it typically fires right up with no hesitation.
> > 
> >          
> > 
> >         12 volt battery is well charged, and a few years ago I had the starter rewound for 12 volts, so there’s no shortage of cranking power and it turns the engine over nice and fast (but not crazy fast like it used to with the 12V battery on the original 6-volt starter).    
> > 
> >          
> > 
> >         It does have pretty high compression, resulting I assume from a rebuild shortly before I bought the tractor ten years or so ago, and which helps it put out about 55 hp on the dyno.  I can’t remember the compression numbers right now, but I remember checking compression after buying the tractor and thinking “Wow, those are some high numbers, and all four cylinders are just about dead-on equal.”   When hot the engine typically diesels at shut-down unless I let it sit and idle for several minutes, so I’m wondering if the hard cold starting is related.
> > 
> >          
> > 
> >         Anybody have similar experiences or recommendations?   The other thing I was wondering is if maybe the non sequitur is out of adjustment, but I can’t find the factory specs for it in the service manual.
> > 
> >          
> > 
> >         Dean Vinson
> > 
> >         Saint Paris, Ohio
> > 
> >          
> > 
> >          
> > 
> > 
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> > 
> >     > 


 

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