Stator or Switch box??

[mbp102]

I have a 1988 mercury classic 50 45hp. Most of the time it will not fire the top cylinder. The top rpm is about 4200. Then at times the top cylinder will fire and get up to 5200-5400 rmp.(normal specs). It seems to run on all 4 cylinders more often when the motor has warmed up. I have used an inline spark tester which shows the problem. I have also swapped the plugwires, plugs and coil but the top cylinder always has the problem. Can the switch box or stator work intermitting? Someone suggested to me to just change them both. $$$ If that is the general consensus I will.<br /> Thanks, <br />Mark

 

[mellowyellow]

Re: Stator or Switch box??

get a manual and follow testing proceedure to<br />find cause. no sense throwing parts at the problem<br />without knowing for sure, especially expensive<br />ones.<br />may be switch box, may not....<br />M.Y.

 

[The Marine Doctor]

Re: Stator or Switch box??

The Stator will not knock out 1 cyl on that model.<br /><br />It will knock out 2cyl's or all 4cyl's but not 1cyl<br /><br />TMD

 

[Mikael-Block]

Re: Stator or Switch box??

Hey..<br />The Doctor are right... <br />Switchbox might be the problem..<br /><br />I had the same problem on my 1984 75 hp.<br />solved the problem....<br /><br />mikael

 

[andrewkafp]

Re: Stator or Switch box??

Does the 1988 have a Trigger.<br />Could be trigger or attached wires perhaps??<br />I had a loose connection on 1 trigger to switchbox wire and lost No 1 cyl. Fixed wire, fixed problem

 

[kenimpzoom]

Re: Stator or Switch box??

I agree with the trigger idea (if it has one).<br /><br />My trigger slowly went out. Top cylinder would sometimes not fire, finally got worse until it would never fire. The trigger was bad.<br /><br />Ken

 

[The Marine Doctor]

Re: Stator or Switch box??

If the trigger is the problem..you will lose 2 cyl's. NOT 1.<br /><br />The reason for this is that the current sent through the #1 trigger...is sent through the powerpack..it then has to return through opposite side of the coil to complete the circuit.<br /><br />Triggers work in Series.<br /><br />As for the 3 cyl models...3 triggers. NOT 2 like the 4 cyl models. <br /><br />TMD

 

[andrewkafp]

Re: Stator or Switch box??

Could be right..<br />As my motor was running pretty bad with that broken wire, backfiring too. Could well have been 2 cylinders out..