Spark Plug Diagnosis

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70spider
Posts: 676
Joined: Fri Mar 14, 2014 3:05 pm
Your car is a: 1970 Fiat spider
Location: N.E. New Mexico

Spark Plug Diagnosis

Post by 70spider »

Image
From what I can determine from the other posts about the color of the plugs, my motor is running rich? It also seems like there is burnt oil on them, the car doesn't smoke much, more on start up and it is whiteish. The other bad news is I have some "blow-by", a fine mist of oil spray out the tail pipe on start up. I just hope the motor last me until Spring, the time schedual to put in the 1608 I am slowly rebuilding.
1970 Fiat Spider 124 Sport aka "Pesto"
2002 Mazda Protege5
2013 Buddy 170i
TStark
Posts: 127
Joined: Thu Sep 26, 2013 10:24 am
Your car is a: 1975 Spider
Location: NE CT

Re: Spark Plug Diagnosis

Post by TStark »

Yeah, thats extreemly rich. The 'oily spray' is likely condensed water and soot.
Confirm your jets are correct and also not swapped around.
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70spider
Posts: 676
Joined: Fri Mar 14, 2014 3:05 pm
Your car is a: 1970 Fiat spider
Location: N.E. New Mexico

Re: Spark Plug Diagnosis

Post by 70spider »

The set I pulled today have been in there since March (4,000 miles ago) and I have done alot of work on the motor since. New 32/36 carb ( I rejetted the primary idle with a 47.5 replacing the 60 that came with the carb), 1800 intake, fuel filter, new Petronix ignition and coil. So in about 3,000 miles I'll find out if those changes were a success.
I did notice after putting one of these, http://www.autoricambi.us/product/LU0-042/Flame-Trap/ , in the crankcase hose my fumes have deminished drastically.
1970 Fiat Spider 124 Sport aka "Pesto"
2002 Mazda Protege5
2013 Buddy 170i
TStark
Posts: 127
Joined: Thu Sep 26, 2013 10:24 am
Your car is a: 1975 Spider
Location: NE CT

Re: Spark Plug Diagnosis

Post by TStark »

Plugs are designed to self clean when things are correct. Therefore as they are are more indicative of the present condition of the state of tune. New plugs will likelyvlook like that in short order, just one drive, and if the mix was sufficiently hot enough the carbon would burn itself off the insulator.
majicwrench

Re: Spark Plug Diagnosis

Post by majicwrench »

You really can tell little from plugs UNLESS you do it under very controlled circumstances. They will color according to the last time they ran. Was car idling? Did car get up to temp?? Heck, the tips are shaded in the pic, that makes them look dark, I can hardly see em.
Ran a stock car in the late 70's, NGK would have us run car on track several laps, shut it down at full speed and coast into pits. Then pull plugs.
I see no deposits, unless you are having a problem I think they look fine. But like I said above, very little you can tell.

What comes out your tailpipe is, like was mentioned, soot and water, not oil.
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