Hi Gus, I have been quietly following and enjoying your thread from the outset. I have not commented before as you have been in the good hands of Jason but if you are experiencing starting problems with your engine perhaps I can help.
Although I have operated diesels over a longer period starting glows quickly and positively became an absolute priority whilst flying control line aerobatic models (competitively that is - just one minute to start the engine, walk to the centre, pick up the handle and take off)
Firstly, though Glow motors will start with much lower compression than Diesels a reasonable piston/liner seal is still required. The kind of engine you have made will easily run on straight fuel ie 80% methanol and 20% oil. The addition of a small amount of nitro - around 5% will improve matters slightly but there really should be no need to go beyond this. Apart from the odd high revving racing engine owned I have never felt the need to go over 5% for aerobatic motors eg OS 35S , Super tigre G21/46 etc.
Assuming you are starting by hand the prop should be around 12 - 13 inch diameter for the first runs preferably with a fine pitch - 4-5". Too small a prop will mean much harder flicking required.
Technique - Fuel the tank and, if you are right handed have the prop at 'ten past eight' position as the engine comes on to compression or 'ten to four' if left handed.
Without the plug connected place a finger over the choke and turn the prop over to draw the fuel through to the carb. Prime the engine by squirting a small amount of neat fuel into the carb and flick the engine over to get the engine 'wet'. This is a 'feel' thing which you will soon become aware of. Connect up the plug and grasping the prop blade very firmly in your hand slowly bring it up to compression. If everything is right in there you will feel a positive knock on the prop as the fuel ignites against the piston - Don't worry it will not fire and start but this is an excellent indicator that it is about too. Back the prop off a little then give it a real good flick over compression when it should fire quite readily.
If you can't get a 'knock' it will mean one of two/three things -
1 There is not enough fuel through the engine ie it's not wet enough - repeat the procedure with a little more prime
2 It's too wet and you have flooded it. Disconnect the plug and close the needle and flick it over to expel the residual fuel.
3? Well check your battery and the plug! - the glow needs to be a nice bright orange at the minimum (sometimes not quite achievable with single cell nicad battery starters - some plugs are 2volt and others 1.5 which can restrict the glow on a nicad if the former) and should be visible through the exhaust port reflecting on the piston/liner wall. A small ammeter in circuit, though not essential, gives a good indication of plug condition in operation and will soon tell you if you have flooded it.
If you are using an electric starter I'm afraid I'm not much help - I have never ever used one in all my time messing with these wonderful little power houses. Just be careful you don't take the engine into a flooded situation and keep on with the starter. You could easily damage your work particularly the con rod
Hope this helps some. Congratulatons on your build, you have made a fine job of it. I hope it starts and runs as well as it looks.
Regards - Ramon
