How often do you change spark plugs and why?

[silverbullet02]

Just wondering. Doing a little experiment. Thanks!:thumbsup:

[seansbaja1982]

I change mine about every 3 years, just for PM..

[Dave Strong]

When the center electrode starts to get a rounded edge, magnifying glass helps to see.

Dave

[mach351]

Only when I melt a piston :eek:

[davemvegas]

often. I own 1 set of spark plugs. I have 3 boats. depending on the plan for the day. I pick a boat to use. and salvage what's needed from the other 2.

[Mr. Demeanor]

I change them pretty often in the little boat but most of that is due to tuning and trying to get a clean plug. They are cheap.
The Opti plugs last forever and are very expensive. I think I have changed those once in 600 hours of use.

[Dave Strong]

I change them pretty often in the little boat but most of that is due to tuning and trying to get a clean plug. They are cheap.
The Opti plugs last forever and are very expensive. I think I have changed those once in 600 hours of use.

I hate trying read a new plug on a plug cut, way easier to read one with time on it. JMO

Dave

[Steve Pope]

Opti and 4 strokes every 400 hours. All others start of each boating season.

[Glasstream15]

BUHWs seem to last forever in my Tower. I change about every 3 years just "because".

[silverbullet02]

When the center electrode starts to get a rounded edge, magnifying glass helps to see.

Dave


Have you found that to have any noticeable effect on performance either at idle or top end?

[Robby321]

BUHWs seem to last forever in my Tower. I change about every 3 years just "because".

Yep on NGK's...same me...(and changing plugs yearly because you feel good about it is wasted money..) Surface gap fine to simple clean out. But like Dave said, the center electrode should be sharp and healthy. Then if not?..toss.

[Robby321]

Have you found that to have any noticeable effect on performance either at idle or top end?

I'll answer for him that. THINK? Electricity takes the least part of resistance, (and thats a sharp point to ground)

[Dave Strong]

Have you found that to have any noticeable effect on performance either at idle or top end?

Not a lot on top end, but on surface gap plugs if you have long no wake zones they seem to clean out a bit quicker. Real cold starts 50deg and colder they seem better as well.
Got burned years ago with a mid to high rpm miss that was not always there, started checking coils, triggers, stators,etc. New plugs fixed the issue, way cheaper than the rest of the ignition system as a first thing to try.

Dave

Dave

[Dave Strong]

Have you found that to have any noticeable effect on performance either at idle or top end?

Not a lot on top end, but on surface gap plugs if you have long no wake zones they seem to clean out a bit quicker. Real cold starts 50deg and colder they seem better as well.
Got burned years ago with a mid to high rpm miss that was not always there, started checking coils, triggers, stators,etc. New plugs fixed the issue, way cheaper than the rest of the ignition system as a first thing to try.

Dave

Dave

[Go Time]

Your suppose to change them???

[XstreamVking]

Just a side note for the opti iridium plugs. You can get the exact same plug from NAPA for 11 bucks ea. Dealers sell them for 22 bucks ea.

[ssv1761982]

I am thinking I should have at least carried a spare set. My 225X ran great all weekend. Not so good today - started and ran ok for about 10 minutes. Stopped to look around and it wouldn't even get on plane after that. 10 min down stream on the Ohio River, 2 hrs upstream. I hope it is just plugs. They are an odd ball too. BPR8EVX I just changed them this spring = 1st time in a couple years. It was similar symptoms.

[Quinten]

Not a lot on top end, but on surface gap plugs if you have long no wake zones they seem to clean out a bit quicker. Real cold starts 50deg and colder they seem better as well.
Got burned years ago with a mid to high rpm miss that was not always there, started checking coils, triggers, stators,etc. New plugs fixed the issue, way cheaper than the rest of the ignition system as a first thing to try.

Dave

Dave

This! Just got done pulling my hair out, carbs off numerous times, checking all the above. Wound up changing parts any way, but after 6 years, I think it was the plugs.

[Dave Strong]

This! Just got done pulling my hair out, carbs off numerous times, checking all the above. Wound up changing parts any way, but after 6 years, I think it was the plugs.

Ya when mine did it the plugs only had about 10hrs on them they looked fine, wouldn't miss all the time.

Dave

[Quinten]

Ya when mine did it the plugs only had about 10hrs on them they looked fine, wouldn't miss all the time.

Dave

Mine either. Sometimes at idle. Hardly never between 1500 and 3000, intermittent over 3400. Drove me nuts. I need to remember in the future, for less than 20 bucks and about 5 minutes, that will be the first, cheapest and easiest thing to eliminate. Heck, after everything I just went through, I might throw a spare set and a plug wrench in the glove box.

[johnboy 88 vegas]

Only change mine when the idle gets bad and takes longer to crank which don't take very long in my modded 2.5 carbed fishin motor. A while back I started running NGK iridium plugs and they last at least twice as long as standard plugs but are not really cost effective.

[whipper]

all season on mine surface plugs. Going to change them tomorrow. Just because. No noticeable effects of not doing what they should still just a little long in there. I used to change my gappers every two weeks!!

[Robby321]

Gotta think here, as plugs in cages go 50,000 miles. And I will never do a "Champ plug" in anything again...now always NGK's. Boats 2 cycle, the yard stuff, dirt bikes,(2 stroke)..anything,. My Harleys hate Champs too! Simple Mex made junk.....

[Lockjaw]

Gotta use a champ in an OMC. I have never had an issue with them.

[dompie99]

Same here, I do that every season start, just for my brain to relax about spark issues all year around... ( oh yeahhh ) and by the way, is it a good idea to replace gap plugs for Surface plugs if heatrange is the same »????

[JohnR]

Not a Champion fan but some of the very experienced OMC guys on here said run them. The Champions for my looper were dirt cheap at Autozone.

I run the recommended NGK in my Merc and get them at thesame place. CCheap to slam a set in at the beginning of the season and keep the old set onthe toolbox as spares.

John

[Mr. Demeanor]

Same here, I do that every season start, just for my brain to relax about spark issues all year around... ( oh yeahhh ) and by the way, is it a good idea to replace gap plugs for Surface plugs if heatrange is the same »????

I had been thinking about trying them but what I read was that you need a higher energy ignition. My old Yamaha probably doesnt have the spark power to see any benifit. They are supposed to greatly reduce detonation by not having a this metal strap sticking into the hottest part of the combustion.

[Quinten]

Gotta use a champ in an OMC. I have never had an issue with them.

Thats all I ever ran in my omc's. Ql77jc4, or something like that. Worked great in those. The merc does not like champs.

[Quinten]

Gotta use a champ in an OMC. I have never had an issue with them.

Thats all I ever ran in my omc's. Ql77jc4, or something like that. Worked great in those. The merc does not like champs.

[Dave Strong]

I had been thinking about trying them but what I read was that you need a higher energy ignition. My old Yamaha probably doesnt have the spark power to see any benifit. They are supposed to greatly reduce detonation by not having a this metal strap sticking into the hottest part of the combustion.

Going from surface gap to J gap or the other way shouldn't matter. Surface gap have a set gap between ground and the electrode just as you gap a J plug, the advantage of surface gap is it can jump 360deg vs a J gap ground electrode is not a sharp 360 around center electrode. Surface gap plugs can be found in the same heat range with different gaps, J gaps tend to work best if you spend a lot of time at idle they are more exposed to combustion flow and will clean out when the hammer is put down after a extended idle period, + they are easier for most to do plug readings on.

Dave

[Ron V]

About every other season, whether they need it or not.