Spark plug questions

[Mark_Alan]

I have a 1982 Johnson 235 HP model no. VJ235 TL CNE. The current spark plugs are Champion UL-77V rimfires and seem to foul way to easily. Was wondering if it would be OK to use the QL77JC4 instead, and what the gap setting should be.

Are the rimfires used for clearance issues or something. This motor has never been torn down or modified.

 

[boobie]

Re: Spark plug questions

You could try a QL16V in it. That mtr was supposed to use surface gap plugs due to clearance probs.

 

[Mark_Alan]

Re: Spark plug questions

So what is the difference between the UL77V and the QL16V if they are both surface gap? Is the QL16V less susceptible to fowling?

 

[seahorse5]

Re: Spark plug questions

So what is the difference between the UL77V and the QL16V if they are both surface gap? Is the QL16V less susceptible to fowling?

There are all different styles and types of surface gap plugs, they are not all the same. Some have a smaller center electrode, various alloys for longer wear or cheaper manufacturing, different ring gaps, and in the case of the QL16V, an extended nose.

 

[boobie]

Re: Spark plug questions

Yes, it is less susceptible to fouling.

 

[1993Ssv170]

Re: Spark plug questions

I replaced my plugs and DID NOT CHECK THE GAP and lost a lot of power! Also, it seemed like I had a lot more exhaust smoke than usual. This engine is a 1993 Evenrude 2 stroke. I returned home and checked them this morning... the gap was more like .02. I adjusted it to .035 and the engine looks to be burning the fuel more efficiently. I will test it again next weekend.

 

[boobie]

Re: Spark plug questions

It's not nice to hi-jack a thread. Read the rules at the top of the forum, Thank You.