Changing spark plugs after new powerhead break-in??

steve forsythe

Petty Officer 1st Class
Joined
Nov 7, 2001
Messages
245
My new powerhead has about 1 full (120 gallons) tank of 25:1 mix through it and all was well with the break-in.(we mixed 50:1 in the tank along with the motors 50:1 mix) On the 2nd tank of gas, there is still some oil in the gas tank so it is probably running about 35:1. Now, when i run for an extended period of time, then stop and kill engine for say 10min or longer....it is real hard to start again or keep it running. It wants to sputter and die. If you full throttle it and run for awhile (5min +) it is then back to normal. I am changing the spark plugs today and noticed they were a little dirty. Could this have been my problem? Is it normal when running it rich to need to change plugs that quickly, and should i change anything else??? And would fouled plugs have caused my symtoms? It is a 2000 Merc 200hp carbed. Thanks.
 

jgmilberg

Cadet
Joined
Apr 28, 2002
Messages
11
Re: Changing spark plugs after new powerhead break-in??

If you are having problems like that I would look at how you add the oil to the gas. If you just dump it into the tank then fill it you don't fully suspend the oil into the gas. Try putting half the oil in a 5 gallon can fill it then shake it up and dump it into the boat's tank, repeat for the other 1/2 of the oil. You might have a bunch of oil just sitting on the bottom of the fuel tank, and that is where the fuel is picked up from, so you might be getting more oil than fuel causing the hard/no start problem.
 

steve forsythe

Petty Officer 1st Class
Joined
Nov 7, 2001
Messages
245
Re: Changing spark plugs after new powerhead break-in??

Thanks, it did run better until i got to the end of the first tank. I just figured that all the moving around would mix it up. One more thing....why do the spark plugs for a reasonably popular motor cost $11 per plug?!!! After i burn through all the oil , should i change them?
 

BKool68

Petty Officer 1st Class
Joined
Oct 14, 2001
Messages
259
Re: Changing spark plugs after new powerhead break-in??

Wow, $11 per plug. And to think I was crying about $5 each.
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: Changing spark plugs after new powerhead break-in??

What kind of sparkplug are you running?
 

steve forsythe

Petty Officer 1st Class
Joined
Nov 7, 2001
Messages
245
Re: Changing spark plugs after new powerhead break-in??

They are NKG i think. They are supposedly recomended for my engine.
 
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