2 Cylinders are not firing

[Mdub]

I have a 75 hp mercury. The 2 bottom cylinders number 3 and 4 are not firing. I have just rebuilt the carbs, and put new plugs in. When i pulled out the new number 3 plug to check for spark, it still looked brand new and did not spark. It was not fauled at all. While i cranked the engine to check for the spark, it seamed that the cylinder was getting gas and the plug smelled like gas. Any ideas how to trouble shoot this problem???

 

[Mdub]

Re: 2 Cylinders are not firing

Also the engine is running on just the first two cylinders.

 

[Mdub]

Re: 2 Cylinders are not firing

I pulled the top two cylinders plugs and the plugs are not fouled but look like they are being used. The bottom 2 plugs on the cylinders that are not firing, both look brand new. Not even a spot of oil or gas on them. Is this normal for a cylinder that is not firing or does it sound like they are not getting gas?

 

[Mdub]

Re: 2 Cylinders are not firing

bump

 

[sschefer]

Re: 2 Cylinders are not firing

What year is the motor, is it a inline 4 or V-4 ? Some four cylinder inlines do not have the correct fuel mixture in 3 and 4 below 1800 RPMs and won't fire. This is by design. You should still have spark so test the trigger and then the stator. If you don't have a Manual get one, it will walk you through some basic tests. Cheap investment to avoid confused results.

 

[Mdub]

Re: 2 Cylinders are not firing

The motor is a 1984 inline 4. That is interesting to know. I will order a manual tonight. I was using a generic manual but it is hard to understand.

 

[sschefer]

Re: 2 Cylinders are not firing

The motor is a 1984 inline 4. That is interesting to know. I will order a manual tonight. I was using a generic manual but it is hard to understand.

Let me guess, you have the Seloc manual. If you can find the Clymers it's a lot better.

 

[blue fin 2]

Re: 2 Cylinders are not firing

It"s probably the stater it is underneath the flywheel, if you change the coil leads from the lower coils and turn the engine over with the plugs out you should see spark , good luck blue fin 2