Emerald Fox
Cadet
- Joined
- Apr 14, 2004
- Messages
- 16
Greetings from Helsinki, Finland!<br /><br />I recently bought a small open boat with an Evinrude 20hp 2-stroke 2-cylinder outboard engine. I don't know the accurate history of the servicing to this engine which is from 1997, model number BE20SEEUM, and one of the first things I did was to put in 2 new spark plugs of the same type that were in already, this plug = QL77JC4 (apparently without the Q is fine, the additional Q just means it's better for suppressing radio waves caused by the plug).<br /><br />I have sometimes changed plugs in cars and have noted that often nowadays the plug gap is already the right size from the manufacturer, so you don't need to open or close the gap. And these plugs I just put in. In the engine handbook there is no mention of spark plug gap size (odd, that!?!).<br /><br />Because the engine was difficult to start I took it to Telva, a company in Helsinki that deals with Evinrude/OMC engines, and I asked them what should the gap be. They said 0.9mm (millimetres). I have not yet had the chance to check the plugs in the engine (did Telva open the gap?) (and the boat is not accessible right now) but yesterday measured the gap of the other 2 plugs that came in the same packet and that was 0.7. 0.7 seems to work fine anyway (the starting problem was a blocked fuel pipe).<br /><br />Does anyone here know what the gap should be?<br /><br />Thanking you, Ross Turner<br />(kivikettu@hotmail.com)