[wessex_man]

It a case of elimination. Fuel and sparks are the obvious main sources.
You have fuel but check the level and fuel lines jets for blockages. When it starts how does it run?
Also how old is the fuel you are using? This new E stuff doesn't keep as long.
Re sparks  as Paul says Changing the plug is the first port of call,
Checking the ignition timing wouldn't go a miss.
A weak spark could also also be an issue.

[Exstress]

Thank you Paul.

The starting problem has been with me for some time before the piston change. The carb was new from Amal in 2018. I will check all the parts are the correct numbers / settings.

The plug cap is a "Lodge" suppressor type which I will change now.  The plug is a D9 but I have ordered some 3/4" plugs after reading the previous "Furry plughole" posts.  Is it ok to remove the carbon which is preventing a 3/4" plug from screwing right in whilst the head is in place? Is there a particular tool for this operation?

Regards, John

[phutton]

The plug recommended in the 1935 Manual is the Lodge H1, now obsolete of course! The nearest equivalent, according to the Green Sparkplug Co website is the Champion D9. These are both 1/2" reach plugs. Many members with M9s use a 3/4" reach plug (see "Furry Plughole" thread previous to this one).

Regarding your cold starting, is your carb worn, and does it have the correct settings? If not, starting will be difficult and tick-over erratic. Settings should be: Type 76/001, choke dia 15/16", main jet 140, needle jet 106, needle posn 3, slide 6/0524.

Finally, have you got a decent spark? Check contact breaker points gap, clean the pick-up ring, check the pick-up brush, check the condition of the plug lead. Are you using a suppressor plug-cap? If so, throw it away!

Should have asked earlier, but did it start OK before you changed the piston?

[Exstress]

1935 Model 8, Cold starting issues.

Hello, after a recent piston change on my model 8 I have a few queries on which I would like advice.

1, Please advise the correct spark plug for this model.
2, It is very difficult to start when cold. Would this point to the mixture being too rich or too lean?

Thanks, John