i had a back problem some months ago and in the cold weather i couldn't start my m20. now its hot i tried again yesterday. it started relatively easily although petrol leaking from taps and cork inserts. ran ok for 10 to 15 minutes. then i stopped it. tried starting it a few minutes later. it was fine. then tried 20 minutes later and it didn't fire. it has a new correct spark plug gap checked.
i had worried that problem was blocked pilot jet and old petrol before. this is new unleaded petrol.
what do people think.
i wondered if it was magneto and problem of starting when hot (only ok when cold again) but dont see why it should be this.
all advice greatly welcomed. i want to have my bike back as an easy starter as i am getting on a bit now and kicking is a lot harder than it used to be. thanks to all who can help. peter with best wishes
It could be the 'hot magneto' problem. When it is not starting, does it have a nice healthy spark at the plug? i.e. with the plug removed and held against the head. A fat spark when it is cold and not so when it isn't would be a fair guide as to something wrong with the electric side of things. I would check out the plug, although it is new you may have bought a duff one. A pal of mine once did a major strip of a bike and all it turned out to be was a couple of new faulty plugs! Being new he never thought to check them. Process of elimination. Start with the easy bits and check back. Sticking valve when hot? Valve lifter out of adjustment and when hot expansion moves it just enough to upset things? Just chucking things in worth a quick look at.
I used to carry some bottled water and a couple of face flannels when I stopped would soak the flannel and put them on the mag it worked kept me going until the winter then took mag off and had it rebuilt
just wanted to say thank you and let people know that i have got my m20 (named Greeny by one of our daughters some time ago!!) started. joy of joys. thanks for the helpful and reassuring advice from out there. it instilled confidence. i think i have needed new petrol, cleaning points and checking and changing spark gap. i'm hoping mag is ok. so thanks again. back in the land of the living. all best
