1985 85hp running funny.

rriley563

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I have an 1985 85 hp force. Starts a little on the hard side (9 outta 10 times you have to use the fast idle). Sometimes stalls at idle but that is rare and from what i have gathered from here is that this motor does not like to run slow speeds. other than that the motor runs fine but is a little sluggish. It no longer seems to top out. (also doesnt seem to top out in fast idle either. I used to be worried bout it overreving in fast idle). I have decarboned it. checked and replaced numerous plugs. and by reading the plugs it does not look (nor does the motor sound like) i have a dead miss. have not checked compression but i dont think it is bad and read on you will understand. Had a fuel leak. fixed it no change. been through the carbs no change. but here is the kicker. if you turn gradually (what way depends on the day) you can hear the motor kick in and feel the boat take off. sometimes only for a second sometimes if you hold it in a gradual turn it will keep up for a min. I have checked the linkages and made sure wot is wot. and I am doing this all at wot. I ran it with hood off and wiggle tested every wire hose and connector on the motor. I am at my wits end. I use the boat to this day bout everyday. I am not scared to take it out as overall it runs ok. But bugging me that Ive lost my top end power (kids like to tube)
 

Bifflefan

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Re: 1985 85hp running funny.

It sounds like like you have done all that a non pro mechanic can do.
If it is enough to bug you that much maybe its time to bit the bullet and take her in for a pro to look at.
I have a hard time parting with money myself, but I know when its time to say when also.
 

pnwboat

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Re: 1985 85hp running funny.

Sounds like you may have a fuel supply problem? Have you changed the fuel pump diaphragm? Also the primer bulb?

Make sure the fuel tank vent is not plugged. You can test by cracking the gas cap enough to let air into the tank.

Maybe a problem in the tank itself. Since it seems to kick in while you're in a turn, when the fuel in the tank goes to one side. Maybe a restriction, or the pickup tube has fallen off. I would take a look inside the tank. You can remove the cover where the fuel gauge sending unit is located. Usually there are five screws that hold the cover in place. Once removed, you can look inside the tank. The pick up tube is also usually located very close to the fuel sending unit.
 

rriley563

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Re: 1985 85hp running funny.

I have new tanks as last year i had old tanks and was fighting a water in fuel issue. Or so I thought that is when all the probs started so I addressed most of the fuel system. I am going to replace the primer bulb and also the fuel lines and use worm gear clamps instead of the spring ones. I have not checked the fuel pump diaphram yet. Is it under the screws or do you have to unbolt the whole thing?
 

rriley563

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Re: 1985 85hp running funny.

Replaced all fuel lines and primer bulb today and used good new screw type hose clamps. no change. however while out running today it started to run worse i now have no spark on one cylinder switched the primary positive with another coil and the no spark went with it. must be a cdi. checked if i had spark on the extra primary positive that is shared with coil 3. no spark on that one either. are these know to take out one side of the cdi? the wire that leads to no spark are both the orange outlets on the cdi tested cuz i was gonna switch them around? maybe someone already did that once before? gonna look for new cdi but was wondering if the orange ouputs on the cdi have anything in common that could cause the no spark. i dont have a manual so if someone could look who is good with wiring diagrams and let me know that would be greatly appreciated. also anyone with any component tests that could help would be awesome.
 

rriley563

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Re: 1985 85hp running funny.

Tried that but realized that the old press on comp tester was no good. I am missing spark on one side of both cdis was wondering if that had anything in common (some sort of trigger issue) or if both were burnt out. and what to expect for prices in a cdi
 

rriley563

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Re: 1985 85hp running funny.

been reading around and have learned that these are know for bad connections in the connectors and grounds. Anyone else have any of these problems? Any know connector/ground that is commonly known to go bad?
 

pnwboat

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Re: 1985 85hp running funny.

Yes bad connections are not uncommon, especially on a motor that is that old. I have a 1988 125 HP motor and have had to fix broken connections several times. I have a 12 position terminal block on my coil plate where all of the trigger, CD Modules, stator connections come together. There are some spade lug connectors on the wires with a bit of heat shrink insulation covering the lug right where the wire is connected to the lug. I've found in several instances where the wire itself is broken, but it is not visible since it is covered up by the heat shrink. The heat shrink keeps the wire/lug together which gives you the impression the connection is OK. I have since replaced all of the spade lug connectors and haven't had a problem since.

Ground wires are also troublesome. Typically there is one small ground wire that runs from the coil plate to the engine block. The coils themselves are grounded to the coil plate. I added an additional ground wire from the coil plate to the block just to be sure.
 

rriley563

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Re: 1985 85hp running funny.

started checking all conections the other day. ohmed out everything i could. all except between the coils and cdi. Any one with a manual or experience, how are the coils fired does each cdi fire up to too coils simultaneously or does it have two seperate controls to fire two coils individually. are these cdi's known to only burn out one side?
 

pnwboat

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Re: 1985 85hp running funny.

It's very common for just one side of the CDI module to go bad.
 

rriley563

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Re: 1985 85hp running funny.

thanks i was afraid to hear that. Guess i now will have to bite the bullet and buy a cdi. thanx to all who have helped i will post more when done.
 
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