Mercury Blue Band 80 hp

[rogerjamesbarnard]

I have just bought a boat with an 80hp Mercury Blue Band engine, it was running fine but is now only firing on cylinders, 3 & 4, checked HT leads and coils, switched power feed from 3 to 2 and perfect spark. Any suggestions would be welcome.

 

[achris]

Re: Mercury Blue Band 80 hp

Hello Roger and :welcome: to iBoats.

I assume this engine has 4 separate ignition coils, one for each cylinder and you have lost spark on 2 cylinders. The trigger coil arrangement on this engine is 2 pairs. One pair does 2 cylinders, the other pair does the other cylinders. The colours are violet, white, brown and white/black. I can't remember which wires are paired together, but if you have a multimeter you can find out. I suspect you'll find one pair, but not another.

If that is the case, then you need a new trigger assembly.

Chris........

 

[rogerjamesbarnard]

Re: Mercury Blue Band 80 hp

Hello Roger and :welcome: to iBoats.

I assume this engine has 4 separate ignition coils, one for each cylinder and you have lost spark on 2 cylinders. The trigger coil arrangement on this engine is 2 pairs. One pair does 2 cylinders, the other pair does the other cylinders. The colours are violet, white, brown and white/black. I can't remember which wires are paired together, but if you have a multimeter you can find out. I suspect you'll find one pair, but not another.

If that is the case, then you need a new trigger assembly.

Chris........

Hi Chris,

Yes there are 4 separate coils and they all seem to be OK, Don't know what you mean by a trigger pack, is that a power pack, which I think boosts the initial spark. if so why is it still firing on 3 & 4, as I think there is only 1 power pack for all 4 cylinders.

Roger

 

[achris]

Re: Mercury Blue Band 80 hp

The ignition system comprises of the stator (generates the high voltage), the switchbox (fires the coils), the coils (fires the spark plug) and the trigger (provide the signal to the switchbox about WHEN to fire the coils). The trigger lives up under the flywheel, and it has 4 wires coming down from it to the switchbox. Brown, Violet, white and wht/blk. The trigger consists of 2 pairs of coils inside it. If one pair has failed, you lose spark to 2 cylinders.

Chris.......

Here's a scan from the service training handbook. Block diagram of how the ignition system on your engine works... You can see by this that if you have a broken wire or failed coil in the trigger, it will effect 2 cylinders.

 

[rogerjamesbarnard]

Re: Mercury Blue Band 80 hp

Hi Chris,

Thanks for your assistance is there any way of testing the trigger, so far 2 different fitters have come up with 3 different possible solutions, however your suggestions seem to make more sense.

Suggestion 1. POWERPACK HAS FAILED
Suggestion 2. SWITCH BOX ASSEMBLY / HARNESS, PRIMARY (CYLINDERS 1 AND 2)
Suggestion 3. STATOR ASSEMBLY

Perhaps you could let me have your thoughts on these 3 options.

Thanks a lot

Roger

 

[achris]

Re: Mercury Blue Band 80 hp

Hi Chris,

Thanks for your assistance is there any way of testing the trigger, so far 2 different fitters have come up with 3 different possible solutions, however your suggestions seem to make more sense.

Suggestion 1. POWERPACK HAS FAILED
Suggestion 2. SWITCH BOX ASSEMBLY / HARNESS, PRIMARY (CYLINDERS 1 AND 2)
Suggestion 3. STATOR ASSEMBLY

Perhaps you could let me have your thoughts on these 3 options.

Thanks a lot

Roger

Option 4. trigger failure....

How to test the triggers. There are 2 coils in the trigger assy. Each end of each coil comes down to the switchbox as one of the 4 wires, white, brown, violet, wht/blk. So, 2 wires form a 'loop'. Using a multimeter, find each pair. My bet is you will find one pair, but the other pair will show as an open circuit....

Chris........

 

[Faztbullet]

Re: Mercury Blue Band 80 hp

You can flip the trigger wires also to test trigger, remember that #1 is at bottom of pack. Most likely it going to be the switchbox but test trigger as achris suggested. Below is switchbox testing but it wont tell you if SCR or internal rectifier is bad.

 

[Dia75]

Re: Mercury Blue Band 80 hp

Hi, I have the same issue with my Mercury 80 hp, I have replaced the spark plugs,CDI/Trigger and the stator and still no spark would the mercury switch (small blue thing with 2 wires one goes to earth) that's next to the switch box be the cause?.. or the rectifier?, hopefully a new battery might solve this? low battery power and slow turn over might cause the lack of spark?

Also the tilt and trim works, but stops half way lifting up, after putting power to the solenoid it will raise all the way, has no issue lowering down completely.. any ideas?

 

[achris]

Re: Mercury Blue Band 80 hp

Hi, I have the same issue with my Mercury 80 hp, I have replaced the spark plugs,CDI/Trigger and the stator and still no spark would the mercury switch (small blue thing with 2 wires one goes to earth) that's next to the switch box be the cause?.. or the rectifier?, hopefully a new battery might solve this? low battery power and slow turn over might cause the lack of spark?

Also the tilt and trim works, but stops half way lifting up, after putting power to the solenoid it will raise all the way, has no issue lowering down completely.. any ideas?

Hello Dia75, and welcome aboard. As this thread 'belongs' to 'rogerjamesbarnard', may I suggest you start your own. You'll also need to add more information, like what type of ignition system (one coil and a distributor or 4 separate coils), maybe include the engine serial number too.

Chris.....