spark plug change

[reevio11]

just done the spark plugs on the 172 and it now seems as if its firing on 3 cyclinders i took the inlet back off all the leads are on correctly and in the correct order dodgy lead ? any ideas cheers guys

 

[reevio11]

ive just checked all the leads for continuity and resistance and there fine duff plug maybe
i just took it down the road and its awful to drive

 

[Chris_786]

pics of how you've got your leads?

 

[Chrisjk]

Did you check the gaps on the plugs?

 

[reevio11]

If your looking at the engine gb end cylinder 1234 the leads have 1234 and on the coil from bottom rigth 1next along 2 then top left 3 then top rigth 4

 

[reevio11]

Did you check the gaps on the plugs?

no i just assummed they were correct i could put the old plugs back in see if this makes a difference as the engine ran sweet before i changed them

 

[Chrisjk]

You're always meant to check them, its very easy for then to take a knock in transit, on the shelf etc. Pop the old plugs in and see what it's like.

 

[reevio11]

il let you know the outcome

 

[reevio11]

just refitted the old plugs and its running fine guess there be going back then

 

[Djw John]

What new plugs did you get?

 

[Sean6545]

Never adjust the gap on a platinum tip plug.

 

[reevio11]

i got the ngk platinium tip ones

 

[Djw John]

Weird, were you able to work out what one wasnt firing at all?

 

[reevio11]

no as they all looked clean after a small run and it was internitant not arching a spark all the time must be a dogey tip or something