[diaao]

I have purchased new spark plugs WR7DC+
I need a help regarding the correct spark plug gap for my 1972 350sl

 

[daryn]

It sucks finding the basic information. I couldn't find the information for my motorcycle either. I think somewhere between .032 and .036 is what I did. I just measured the gap on the old plugs and did the new ones the same.

 

[rowdie]

.8mm ( .03150 ) according to CD. (.028 to .032 according to POS Haynes)

 

[nobby]

I have purchased new spark plugs WR7DC+
I need a help regarding the correct spark plug gap for my 1972 350sl

The last time I bought the correct Bosch plugs for my SL, the gap was stamped on the box.....032 / .80 MM

 

[daryn]

I bought a set of plugs yesterday to see if that was my problem. Finding the WR7DC plugs is difficult, bosch changed the numbers to a 4 digit number. The plugs I got are WR7DC+ bosch # 7900. Hopefully this helps other people find the plugs. The parts store guy wanted to sell the the WR9DC but I insisted on the 7s.

 

[MBGraham]

I have purchased new spark plugs WR7DC+
I need a help regarding the correct spark plug gap for my 1972 350sl

From what I recall, those plugs (I used to have them) are already set to the correct gap. I checked them and they did not need adjusting. Gap was 0.032".

I now have NGK plugs and gap is same.

BTW, those WR7DC+ plugs are resistor plugs. Many use them but some say we should use non resistor plugs. I would agree if the car has the original OEM wires with resistors built into the ends. But new Bosch wires don't have the resistor ends and those resistor plugs should be fine.