Take a look at my spark plugs. What do you see?

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velozi

Take a look at my spark plugs. What do you see?

Post by velozi »

Year old plugs. 5,000 miles. None were oily, broken, or in really bad condition. What do see and any improvement suggestions.

Plugs: NGK BPR5ES. No pressure test results yet.

#1 had small amount of oil on resistor ring but nowhere else. Carbon deposits. Light brown core.
#2 no carbon deposit. White core.
#3 seems to be the worst one. The other side of #3 core was whiter than the side shown. More carbon deposit than others. No breaks or too much wear on core or resistor.
#4 Rust on resistor. Small amount of carbon. Whitest core of all.

Car runs fine. Burns a maximum of one quart of oil between changes.

All plugs went in with a 0.027 gap and came out around 0.033

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SLOSpider
Posts: 1140
Joined: Wed Mar 03, 2010 2:10 am
Your car is a: 1973 124 Spider 2.0FI
Location: Lompoc, Ca USA

Re: Take a look at my spark plugs. What do you see?

Post by SLOSpider »

Plugs look good but I would do a compression test while you have them out to check on #3 issue. The whiteness of the plugs can be a sign of running lean but then again 5 k miles is not very long. I looked at mine after a couple of hundred miles of driving and were as white as when I put them in. I may try to fatten up the carb jets to see if there is any difference. Running lean can also lead it to running hotter in the chambers. Perhaps a colder plug number would help?? Any one elses thoughts.
1975 124 Spider
1976 Mazda Cosmo http://www.mazdacosmo.com
1989 Chevy k5 Blazer
1967 GT Mustang Fastback
majicwrench

Re: Take a look at my spark plugs. What do you see?

Post by majicwrench »

Well something is less than perfect with #3, but I wouldn't get too concerend. Compression ck good idea. Other three plugs look like running too hot, if not for that #3, I would be tempted to put a cooler plug in.
THis carbed or FI??
So Cal Mark

Re: Take a look at my spark plugs. What do you see?

Post by So Cal Mark »

I would think the valve seals on #3 could be leaking a bit
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