I bought some Bosch Platinum spark plugs(single tip) and I used the recommended gap of 50, but I got misfire, so I gapped them at 55 and again misfire. The stock spark plugs are gapped at 50, so how come I get misfire when I gap the new ones at 50. Should I go lower? Maybe 45? Help me out fellas.

 

The Bosch plug is an excellent plug. I've had alot of success with them, and currently use the +4's with a mixture of nitro occassionally. Leave them as they are when you take them out of the box, don't jack with them. It'll be to no avail if you do. You'll scratch the platinum coating, and that'll be one of the contributors to a misfire.

 

The misfire is probably a plug wire that is not tight or a bad plug....not the gap....moving this to the appropriate forum.

 

plug wire have been changed and i triple checked to see if they were all tight. they were preset at 50 but it still misfired. I think i'm just going to toss them and look into another brand.

 

oh BTW is there any noticable difference between the single, dual, and 4x tipped ones? am very curiouis about that cause I am gettin new plugs soon. thx

 

the first set i used were the 4x tipped ones(also preset) and i got misfire too, so i went back to autozone and got the single tip (preset as well)and the same crap. stay away from Bosch. i'm reading a lot of good things about ngk spark plugs. i think I'm going to go with those.