replacing spark plugs?

[illinoisbassfishin]

I just bought a Ranger boat about a month ago and it came with a 2001 Johnson 175 Loop Charge V6 and says it has the optical ignition system. I have only had it out 5 times and it runs great going down the lake but hasn't been idling consistently (sometimes it will idle great, other times not so much) It could be a mixture of the Pennzoil XLF (don't care for that oil) cheap oil that the previous owner was running through it that is making it idle weird, plus it sat for 6-8 months without being ran so the old gas probably isn't helping either. I took the spark plugs out and they looked pretty dirty and a lot of black oily crap on them as well. It will start up just great and other times it will idle just great. Even on a cold morning it starts just fine the times I've had it out put it likes to spit and sputter sometimes when it's idling until and sometimes it will spit and sputter till it dies and sometimes it will eventually come out of it and idle. My friend has an electric oil transfer pump so we are going to pump out all the pennzoil out of the oil reservoir tomorrow and put evinrude e-tec xd50 (which is what Johnson/Evinrude reccomended when I called them) and I am going to change out the spark plugs and see what that does.

My question is what kind of spark plug should I get? I've always been an NGK fan but it calls for a "racing series" Champion which is a "QL78YC" or I can get the NGK number "BRP8HS". I have a friend that is a mechanic and is real big on the new iridium plugs and I also saw that I could get a cross referenced Denso Iridium plug for the motor as well. Is it going to hurt the motor if I go with the Denso iridium or the NGK or should I just stick with the Champion even though I'm not a fan of them?

My last boat had an old inline 6 mariner on it and I know I could tell 10 times difference in idling and smoothness when I quit using pennzoil in it and went to mercury or quiksilver oil so I'm hoping that will make a big difference in this motor. I also have ran about 20-30 gallons of gas in it making runs down the lake the times I've had it out and everytime I've got gas for it I have put sta-bil marine formula in it so I just thought I would add that in as well. Any help would be appreciated.

 

[sutor623]

Re: replacing spark plugs?

You said old crappy gas, are you still running that trash through your engine?

 

[boobie]

Re: replacing spark plugs?

Stick with the QL78YC's. The manufacture recommends them and they must know something.

 

[illinoisbassfishin]

Re: replacing spark plugs?

No Sutor it has 40 gallon gas capacity and it only had about 10-12 gallons of that old gas in it and it is now completely gone and has had fresh gas with Sta-bil ran through it for 2 or 3 fishing trips now. I'm thinking what old gas was in it may have fouled a plug or just got them in bad shape because a few of them were pretty black as well so I'm going to go ahead and change them out before I go fishing next. Using an oil transfer pump today to get rid of the pennzoil out of the oil reservoir as well and switching to the evinrude xd50 that is recommended. Some people don't believe that oil makes a difference but I'm a firm believer that oil does make a difference in a 2-stroke. I had an older 83 mariner 115 inline 6 on my last boat and I started with the Pennzoil and it seemed to keep idling worse and worse as time went on so I switched to the Quiksilver and it started idling like a dream again and I did asbolutely nothing else to it other than change oils. So I myself am a believer that oil can make a difference.

 

[Chris1956]

Re: replacing spark plugs?

If you pump all the oil out of the resevoir, you will need to bleed the OMS system and run the motor on premix, until you are sure it is injecting oil. I recommend against this for obvious reasons.

In addition, the oil is not your issue, IMHO. It is likely you have slightly dirty carbs, however, you can run it with fresh gasoline and then decide what repairs you want to make. I use the Wallyworld TC-WIII oil in my '98 Johnny 150HPV6, and it runs fine...

 

[Chris1956]

Re: replacing spark plugs?

Also, run the QL78YC plugs in that motor. You need a special Q-type Supressor spark plug. See if you mechanic friend is familar with that....

 

[illinoisbassfishin]

Re: replacing spark plugs?

Thanks for the advice Chris. I won't completely pump the oil out then. The mechanic told me I could just mix the evinrude in with what pennzoil was left and it wouldn't hurt anything so I will just pump out a big majority of what is in the reservoir or maybe just drain it half way and then top it off with the Evinrude xd50 because I'm going to stick with my opinion that oils make a difference. Have raced and rode 2-stroke bikes all my life as well as have some experience with other 2-stroke motors and oil can definitely make a difference. That cheap stuff isn't refined as well in my opinion and it's cheaper for a reason. You can even look at a bottle of the Pennzoil and it says it is a LOW ASH oil while if you look at the Mercury or Evinrude oil it says on the bottle it is a completely ASHLESS refined oil. Like I said to each their own and everyone has their own personal opinions but I saw the difference between Pennzoil and Quiksilver in my mariner first hand and it was a night and day difference and I did absolutely nothing to the motor other than change the oils. I don't know that Sea Foam is going to be any different than the Sta-bil Marine Formula but I will try to put a can of it in each tank next time instead of Sta-bil and see what happens. The motor runs like a champ as it is and has excellent hole shot and starts with a turn of the key even the day I took it out and it was only 20 degrees that morning so whatever it is it's just something small and stupid I'm sure. A few of the plugs are pretty nasty looking so chances are that's all there is to it because I've saw bad plugs run good going down the lake but not idle as well because they aren't burning as hot on idle as they are WOT. The mechanic told me when you have a motor that starts and goes down the lake just fine and pushes that boat at about 65 mph with 40 gallons of gas there definitely can't be anything major wrong with it. Also just as preventive maintenance I am going to change out the fuel filter.

 

[cyclops2]

Re: replacing spark plugs?

Have you ever used SEA FOAM in any cars or boats ?

Buy only the SEA FOAM.
It WILL NOT harm anything. Even if you add not enough, just right, or way too much. It removes anything bad over a couple of tankfulls of fuel in O B. Water included.
IF NOT to much. Gas companies, distributors tanks & stations are back to watering gas to increase their profits.
It clears up so many idling problems from bad gas or oil. Good oil sometimes IS MADE poorly.

Buy a can & read the directions, NOT always needed.

Hope your problem is Just temporary & clean out works. Post back if the SEA FOAM & a readjustment of idle settings works.

I will agree with you on older Quicksilver OB oil. It ran TOO clean!! Plugs were always a perfect light brown.

I troll a lot. So good oil makes a HUGE DIFFERENCE in the idle .

 

[illinoisbassfishin]

Re: replacing spark plugs?

I will definitely try some sea foam and see what happens. I have always use the sta bil and never had any problems and always put it in every time I put gas in the boat. I will skip the stabil for 2 or 3 tanks and use sea foam instead and see what happens.

 

[cyclops2]

Re: replacing spark plugs?

This Great Depression we are in, is going to last a LONG time.
As a result people in bussiness are being FORCED to cut corners delibertly or unknowingly.

The end result is going to be MORE & MORE poor running engines as time goes on.
It can be ANYTHING built or mixed up liquids.
Bad replacement parts should be going pretty good by now.

DO NOT blame the Chinese or any other country. American bussinesses & the USA congress paid for the complete startup costs of CHINA.
We could not send the most modern automated factories to ALL CHEAP countries around the world FAST ENOUGH.

We still can not......Bussiness goals never change.

At least SEA FOAM has not. Yet.

 

[cyclops2]

Re: replacing spark plugs?

Some spark plug companies make + 5 different styles for the same heat range. I was suprised.
Do a web search of ..........types of spark plugs. Or go to a NAPA store & read a booklet from a plug maker.
A lot of different center & ground electrode shapes. Center wires. ETC.

 

[illinoisbassfishin]

Re: replacing spark plugs?

Don't know when I'll get to take it out and run it because of work, but I have all new factory listed champion plugs in it. says to gap them .028-.031 and dealership said to gap them at .029 so I did. Pumped Pennzoil out of reservoir and put in gallon of evinrude xd50 (dealership said not to drain reservoir completely because it could cause an air bubble or something so I didn't drain it completely. I also got a new fuel filter, and some evinrude/johnson fuel system cleaner that I will run through both of my 20 gallon tanks one time to clean out. They told me that they reccomend the startron additive after I run the Evinrude through because it has all the cleaners you need and stabilizes fuel at the same time. It must be good because they only had one bottle left and they said it was hard to keep in stock. Also my starting battery was weak and junk so I installed a new deka marine master starting battery. Hope all of this will help it run better than it already does because it already ran pretty good.

 

[illinoisbassfishin]

Re: replacing spark plugs?

Also the manual says to run a minimum of 87 octane fuel in it which obviously is the lowest I can get around here or anywhere that I know of anyways. I was wondering can I run the 89 plus, 91 premium or the 93 premium ultimate from BP?