1986 Merc 200

[Wink]

Sorry for prev posts, in error!!<br /><br />I have typed this 3 times hope it goes this time!<br /><br />1 afternnon approx 14 months ago I went to launch my boat, when I started it it idled extremely high, approx 3200 rpm. I manullay held butterfly's closed and it still ideld at that rpm, I said what the flip, Figured that maybe a stuck float pouring gas into cylinders. So home i went, soaked cars in a gal bucket for a couple days, changed seals, blew out thourgly. Be the way I am, I ripped out my ENTIRE FUEL SYSTEM, aluminum takn all hoses filters, vent the whoe nine yards!<br /><br />Nest trip it idled correctly but I be ****ed if the thing would not get up on plane, it would obtain approx 3000 rpm, alsmost enough to get it to fall on plane. <br />I was told sounds like timing issue or stator problem, SO I then REPLACED stator, 3 coils and wiring harness. It is in my nature to replace all associated parts with a sypmtom, cray yess, but been bit to many times by a 10 cent part! I'' be darned same result, was told timing is off, reset to factory specs, same result, and by the way, did start with compression check. So to recap, carbs rebuilt, new fuel system and stator 3 coils, and wire harness.<br /><br />Now I ASSUMED, that the 2 switchboxes, 1 controlled left bank, 1 for right, however I have been recently told that 1 is high rpm 1 is low???????<br /><br />Also told that MERC uses a 2 step staor, Ie low rpm...to 3000, high rpm to 6000???<br /><br />SO the same person recomended 1 more trip, put boat WOT and push on choke, if accelerated, carb issue, if falls on its face, no carb issue. He also belives that if no carb issue it is the high speed side of stator.<br /><br /><br />SO in conclusion, how can I static test high side of stor, or must this bee done under load while running, also any other suggestions would be GREATLY appreciated.<br /><br />PLEASE SOS MAYDAY, It has been 14 months and I really would like to be back on the water!

 

[12Footer]

Re: 1986 Merc 200

Stator can be checked staticly, but it requires the book,and I don't have that.<br />When you go to test,however, after the stator thing, and it does the same thing (Gawd forbid!,after all that time off the water!!),,IF it wont give full rpm,then once warm, give it about half throttle,and cut-off the ignition. Now, go back and pull the plugs and look for a dry one.This would indicate a lazy cylinder, but it would have to be lazy 100% of the time,which would indicate a plugged jet, or delivery to the jet. Or bad reed.<br />Those boxes are identical, I thought. My brother is waiting on one of those,and he found it by switching them out,side to side....Which,when switched, also switched which plugs didn't fire.<br /><br /><br />------------------<br />the Early bird get's the worm...So, he don't have to stop for bait.

 

[MERCMAN]

Re: 1986 Merc 200

The answer to the switchboxes is yes both are the same but they have a bia circuit in both boxes which stablizes the timing if one circuit goes bad it can either retard or advance the timing on the opposite set of cylinders which caused the engine to idle up with carbs closed. You have a switchbox problem and if you replace one you need to replace both boxes because the bad one has or will damage the good box. And as for the stator answer the stator does have a high and low side if high side goes bad the will only run at about 2000 to 2500 rpm's because it is dropping voltage to one of the switchboxes the stator does not control the timing. You also have trigger that tells the switchboxes which cylinder to fire. If there is trigger problem you will lose two cylinder one on either side. Don't mean to be so long winded but this is mercury ignition 101. Hope this helps