78-merc 700 plugs fouling ?

[wildbillhemphill]

I have gone through the carbs twice they are real clean and floats are adjusted @ 11/16ths like the merc manual says I did the timing and sync that I printed from this forum and I can pull the plugs and clean them it will start and run great top and bottom end I stop and let it cool down and the next time I try to start it even without choking it wont start. I'll pull the plugs and clean and dry them reinstall and it will start and run great until I shut it down and it cools off then the same thing all over again. It has NGK plugs in it. Has anyone come across this before????

 

[dlplost]

Re: 78-merc 700 plugs fouling ?

Stop buying the cheap wally world 2 cycle oil. That is a typical sign of the oil deposits fouling the plugs. Get yourself some of the proper Quicksilver, or Johnson/Evenrude oil. YES it does make a difference.

I allways thought if the oil met the correct specs it didn't matter. I learned the hard way, spent most of the summer fighting the same battle you're doing now, runs fine, you can start and stop all day as long as you don't let it cool down, about 20-30 min was the limit I found, if I waited longer than that it wouldn't start till I changed or cleaned the plugs.

 

[wildbillhemphill]

Re: 78-merc 700 plugs fouling ?

Stop buying the cheap wally world 2 cycle oil. That is a typical sign of the oil deposits fouling the plugs. Get yourself some of the proper Quicksilver, or Johnson/Evenrude oil. YES it does make a difference.

I allways thought if the oil met the correct specs it didn't matter. I learned the hard way, spent most of the summer fighting the same battle you're doing now, runs fine, you can start and stop all day as long as you don't let it cool down, about 20-30 min was the limit I found, if I waited longer than that it wouldn't start till I changed or cleaned the plugs.

Well I had a full tank of fuel and I didnt want to waist it so I took those NGK plugs out and replaced them with Champions and that did the trick. (I never had any luck with NGKs on anything I've run them in) I have burned out that gas with the cheaper oil in it and am useing the Quicksilver oil now but it never made a difference on my OMC motors in the past.