300 XS Spark Plugs

[KDFishin']

I want to replace the set of plugs in my 300 XS. I know the correct replacement plug is a IZFR7M, what is the correct gap 0.042?

This is my first XS/Opti motor so is there anything special about replacing the plugs? Anything more difficult than taking the old ones out and putting the new ones back in?

Thanks!

[EuropeanAM]

Correct gap is actually .032".

However, improved idle quality is sometimes achieved when utilizing a .040-.044 gap (not usually necessary, however).

[kllr bee]

Who idles around with a 300XS
Richard

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by kllr bee &raquo;</td></tr><tr><td class="quote">Who idles around with a 300XS
Richard </td></tr></table>

Exactly.

[KDFishin']

Thanks, got them changed out last night. Did not take long. The old one's appeared to be original as they had paint on the same color as the engine. They had 50 hours on them so glad I changed them out.

[Strokerdean]

Gotta get out of the no-wake zone before putting the hammer down. Plus in this cold water it takes forever to warm up.

[allisom21]

how often should they be changed

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by allisom21 &raquo;</td></tr><tr><td class="quote">how often should they be changed</td></tr></table>

Welcome to BBC!

Many such topics are covered in the "Commonly Asked- Commonly Used" post, which is pinned to the top of this forum (it's a good reference).

For information on recommended ANNUAL maintenance, the following post is a good guide:

http://www.bbcboards.net/zerot...gines

[allisom21]

Thanks but what if you are not winterizing your boat. What would be a hour count to use or is it just best to do it once a year regardless of use

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by EuropeanAM, from "Recommend Maintenance for Optimax Engines" &raquo;</td></tr><tr><td class="quote">Here's a list of what we perform here in our shop (and recommend) as "Once per year, or EVERY 100 HOURS, WHICHEVER OCCURS FIRST":</td></tr></table>

See link to the post above.

[Ranchdip]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by EuropeanAM &raquo;</td></tr><tr><td class="quote">Correct gap is actually .032".

However, improved idle quality is sometimes achieved when utilizing a .040-.044 gap (not usually necessary, however).

</td></tr></table>

I'm curious, since a gap of .032" is preferred and the bigger gap not usually necessary, what would cause a 300XS to idle poorly and require the extra gap up to .044"? Has there been a tolerance exceeded or something inside the engine that would cause one to have to gap their plugs differently than the recommended .032"? Thx



Modified by Ranchdip at 12:57 PM 2/28/2011

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Ranchdip &raquo;</td></tr><tr><td class="quote">

I'm curious, since a gap of .032" is preferred and the bigger gap not usually necessary, what would cause a 300XS to idle poorly and require the extra gap up to .044"? Has there been a tolerance exceeded or something inside the engine that would cause one to have to gap their plugs differently than the recommended .032"? Thx
</td></tr></table>

Good question.

The short answer: Variances in fuel quality, octane rating, seasonal or area fuel blends, and ethanol content.

Some fuels simply don't burn well at low RPM, and increasing the gap improves the burn rate.

[Ranchdip]

Thanks

[The Swede]

Don, what is the latest news about the correct gap for a 300XS? Is it still .032" or should it be .044"? My servicemanual says .032".

I usually do not idle that much and during the season it is not that hot in the water in Sweden. In avarage 60-70F from may to oct.

We also have very god gas-qaulity, I always driv at least 91 US Octane (95 European Octane)and above.

Also in Sweden the 95 US Octane (98 Eur Octane) comes without ethanol.

/Patrik

[EuropeanAM]

Patrik:

We're now using .044" gap on the IZFR7M.

You can also look up the latest "list" in the following post:

http://www.bbcboards.net/zerothread?id=310172