Force 85hp 1986 power loss

[jrem123]

Hey to all: Newbie here.<br /><br />Searched though the archives and found some good general info, but I haven't pinpointed down my specific issue so I figured I would post.<br /><br />I have a 1986 Bayliner with a Force 85hp. Very clean condition, never a problem (other than a fowling issue when pulling tubers under low rpm).<br /><br />The other day I was pulling a skiier, and the power band just dropped off a cliff, like it started starving for gas. It starts fine, sounds like it's hitting on all three cyliders, but when I hit the gas there is no power, it ramps up too about half speed after a while but it certainly isn't right.<br /><br />Manually flipping the throttle (with the cowling off) and it coughs, spits, and dies.<br /><br />I've been thinking it's an ignition problem, potentially timing advance, but searching the archives leads me to checking the CD's or carbs.<br /><br />Any hints/tips to leading me down the right path would be appreciated.

 

[boatsmitty]

Re: Force 85hp 1986 power loss

Check your fuel line(filter) for blockage. If ok, check the fuel pump screen for blockage and diaphragm for holes or stiffness. Check your ignition system by using a spark tester on the spark plug wires. Check for spark on all three. If a cylinder is not firing, you can swap spark plug wires and primary wires to check each coil on a different cylinder and verify the problem is with the coil.

 

[bnk999]

Re: Force 85hp 1986 power loss

Wouldn't hurt to pull plugs also and compare- If one looks different than the other two then you may have a problem with weak/intermittent spark or a carb issue for that cylinder

 

[jrem123]

Re: Force 85hp 1986 power loss

Hey guys: Picked up some Seafoam on the way home tonight (been busy every other night this week) and did the deal. Didn't use that much, maybe 6 ounces in a half gallon of gas, did it twice, third start up was hard (it sat for a half an hour while I ran a few errands).<br /><br />Preliminary results look good, it revs nice and smooth, no spitting or coughing, a marked difference. Hopefully the weather will hold out tomorrow and I'll get her out on the lake.<br /><br />Thanks for the awesome website . . . Seafoam is my new freind (next to Google and JBWeld!).<br /><br />Later, John R.

 

[jrem123]

Re: Force 85hp 1986 power loss

Okay, well the seafoam helped, but bottom line is I'm running on two of three cylinders. Ran it today for a little while, brought it home, two plugs are tan w/ some carbon, the center one is clean.<br /><br />So I ohmed out the coils, they are all around 160 ohms. So I'm guessing it's a CDI unit.<br /><br />Read here the other day that each pack services two cylinders, therefore I have a spare. Is there a faq or cut-sheet on how to make the swap? I can imaging my timing will be all screwed unless I change out both the input and output to that module. <br /><br />Any and all help would be greatly appreciated.<br /><br />Thanks, John.

 

[jrem123]

Re: Force 85hp 1986 power loss

well retract that last statement, I have spark on all three cylinders. And I have compression, so it's back to the gas. I must have sucked something out of the tank and cloged a jet. This ought to be fun trying to figure it out.

 

[eurolarva]

Re: Force 85hp 1986 power loss

Keep an eye on them tan plug tips. They should be more black then tan. It sounds as though you are running on the lean side. Also take the clean plug and reverse it with a different plug. Run it for awhile and see if the center one comes out clean or remains the same color as it was.

 

[jrem123]

Re: Force 85hp 1986 power loss

okay. A bud of mine suggested that I switch props, which I did, to no avail.<br /><br />There is horsepower at the low rpm range, but no get-up-and-go.<br /><br />pics of the plugs are <a href="http://jrem.webhop.org/2686.jpg">here></a> or if that don't work try http://jrem.webhop.org/2686.jpg <br /><br />I think I know what you're going to say, that middle cylinder ain't firing. Got a spark, though, I'm thinking gas.<br /><br />Help?

 

[eurolarva]

Re: Force 85hp 1986 power loss

them plugs look like mixture is rich enough. I am more worried about water getting in the middle unit and steam cleaning the plug. Merc had a bad spell with coils for awhile. I am not the electrical guru. Seems to me they were crapping out at high speed. Maybe you can find something on a search in the mercury fourm. Force uses merc ignition parts.

 

[wayne wells]

Re: Force 85hp 1986 power loss

Have a similar problem, get no spark on #2 cylinder. Starts good, but has no power.Looking for a replacement CD module.