spark plug mis conception

[verado7]

i here alot about how the spark plugs on a 2 stroke should be dry at idle and just want to clear this up for anyone intrested .

a 2 stroke spark plug should look a little wet at idle - it will look almost dry if you do a highspeed shutdown which is normal .

hard and no starts are caused by lean idle conditions - check the plugs - probably dry - no fuel .

you should see wetness on the piston tops - this means your getting good lubrication .

a dry plug at idle will cause a lean out on the holeshot or the motor will fall on its face - again - check the plugs ,they will be dry .

another way to tell if the idle mix is right on a merc - watch the motor -it should shake the boat on the trailer - if it runs real smooth ,it's probably a bit lean .

 

[achris]

Re: spark plug mis conception

What does it mean when the port bank (3 cylinders) look a bit wet (oily) and the starboard bank are really dry? Oh, and the pistons have started to leave the engine, via the exhaust ports.....

Chris.....

 

[2dbit]

Re: spark plug mis conception

This is a very good thread to have up. I was actually a bit curious about my Merc. I did a complete tuning on this motor, rebuilt carb, WOT timing, idle timing, carb sync, idle needle valve adjustment, etc. When all was said and done, and I felt the motor was tuned to the best it could be, it would still do the shake at idle. Throttle response is terrific, and has a great power curve. After a week of daily use(not by me), I pulled the plugs for other maintenance and noted that they were both wet, but had a nice amber color(were brand new prior to trip). I tried doing a search for reading 2-cycle plugs, but results were somewhat limited. In the end I chocked it up to: Better too rich than too lean. Sounds more like I've got the thing the way it should be!