Merc. 225 EFI 3.0L 2-Stroke Spark Plugs

**vnemous** · 10-13-2013, 02:52 PM

Oh Chaz does know his stuff, especially if your gonna build some high performance monster

**Rudy** · 10-13-2013, 03:00 PM

That would be fun but the reliability factor is very important since sometimes I am a long way from anywhere and can't break down.

**Chaz** · 10-13-2013, 03:45 PM

Originally Posted by vnemous

Whats wrong with dripping a little oil in the driveway

vnemous ... my ribs still hurt from laughing so hard ...

To everyone else ...

I made reference as to why they foul plugs.

I then asked :

Why do the faster ones get away with running a colder 9 heat range plug ... ?

I got another question ...

If a motor runs so poorly that if will snuff out one brand of plug within hours, why would anyone think a change of brands to be the do all - fix all answer... ?

Only statement I'll make ...

I wouldn't put a Champion in a lawn mower ..

**vnemous** · 10-13-2013, 03:52 PM

Well my driveway is asphalt so it is mostly oil and I own a Harley so............ Chaz see you in a couple of weeks.

**Rudy** · 10-13-2013, 04:13 PM

Before I pave my driveway I would like this unburned waist of gas and oil fixed and run at 70 mph or more again. So I have been running with the BR8HS hotter than the 9 so what can someone tell me about the BZ7HS10?

**Rudy** · 10-13-2013, 05:21 PM

Personally I don't know much about spark plugs but I was reading another forum I think it was in The Hull Truth and someone there had an issue with hot starts on there 225 efi and went back to the champion ql77cc and curd the problem and it may have had something to do with RFI with the ECM. I also don't care what I stick in the freaken spark plug hole if it would help the performance.

**wired247** · 10-13-2013, 05:45 PM

Originally Posted by Chaz

I made reference as to why they foul plugs.

I then asked :

Why do the faster ones get away with running a colder 9 heat range plug ... ?

Plugs dont foul at the high RPM's that the fast ones run at. They foul at low rpm's that fishing motors idle and crawl through no wake zones and God forbid troll at. A colder plug will work in high RPM motors and help prevent detonation but its not going to help low RPM plug fouling.

**Rudy** · 10-13-2013, 06:27 PM

wired247 thank you for clearing that up another good little bit of knowledge. At first I thought it could be a bad sensor and then the ECM would run at a default setting. If it were the air temp it would default to 32f which would be rich. If it were the head temp it would default to 32f and run rich. If it were the MAP I believe it defaults to sea level 14.7psi so that rules out the fouling on the ocean. I unfortunately don't have access to a DDT to analyse the ECM so I thought I would start with the cheapest test. Since some spark plugs create RFI which will effect the ECM to run rich I thought why not try the manufactures recommended plugs. I also realize the NGK BR8HS R stands for resistor which is supposed to suppress RFI from effecting the ECM. So if anyone has any useful recommendations with regards to this subject it would be very much appreciated.

**Chaz** · 10-13-2013, 06:38 PM

Originally Posted by wired247

Plugs dont foul at the high RPM's that the fast ones run at. They foul at low rpm's that fishing motors idle and crawl through no wake zones and God forbid troll at. A colder plug will work in high RPM motors and help prevent detonation but its not going to help low RPM plug fouling.

No one said "race only" or hi RPM . Besides, I cant think of anybody's 3.0 L that makes max power outside of a 6200 - 7000 window.

The runs we go on have area's where we need to idle for a couple of miles . Plow along at 30 MPH for a few more and be WFO for 10 - 15 minutes at a time. And no one needs to stop and change plugs.

What does that tell you ?

And is it the plugs fault if it fouls out, blubber's along, or stick's a slug, in any of the above conditions ?

**Rudy** · 10-13-2013, 07:14 PM

Chaz before this problem I could rev to 5600 rpm this is a stock 250 efi now the best I get is about 5000 to maybe 5200. Do you think I should check the temp sensors then and not bother with the plugs? I have a new set of BR8HS in it now.

**vnemous** · 10-13-2013, 07:26 PM

I trim my 300x up some when idling, seems to keep it from loading up. Never had an idling problem with my 250 efi fishing motor.

**Chaz** · 10-13-2013, 07:36 PM

Well if it's fouling plugs, there is deff a problem somewhere.
Don't know what you have , but the late model Motorola units temp sensors are the same , be they used in the heads or plenum.

77 degrees / 10,000 ohms + - 10%
68* / 12,493
59* / 15,714
50* / 19,902

Less than that , you should be in out of the cold ...

I'd check fuel pressure too, that little screen under the regulator in the VST can get plugged up . Lots of people clean em .. I throw that little &^%$#@ away ...

**Rudy** · 10-13-2013, 07:39 PM

I looked into the NGK BZ7HS10 their 10 bucks a pop ouch. I have also had issues of the engine running cold but this year it seems to be in the right temp neighbourhood. Any thoughts on these plugs 7 is hotter than the 8 I'm using perhaps that would burn better and help with performance?

**Rudy** · 10-13-2013, 07:45 PM

Okay I'll check the screen I have had issues with water in the gas before and have had to drain the vst and change the main filter but never checked the screen. Thanks

**Rudy** · 10-13-2013, 07:51 PM

Oh and as for the temp outside this is Canada if I stayed indoors every time the temp dropped below 50 I'ld only go boating for july and august.
Put a toque on if you know what that is.

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