1991 Force 70 Hp Hard to start when cold

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choskin

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I still havn't got my hands on a workshop manual.I was hopeing someone could describe the cold starting/choke mechanism.<br />I have been told there is an electric choke, when I push the starter key in?<br />I see a electric connector labeled choke?<br />When I look in the barrel of the carb I see a large butterfly vane ,is this the choke?<br />Motor starts fine when warm but when cold takes most of the battery (new, fully charged) about ten cranking sessions.Trying to get home yesterday after day in the sun,Hard to start motor put a dampener on the mood. A great day Though.
 

roscoe

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Re: 1991 Force 70 Hp Hard to start when cold

THe electric choke is a small solenoid operated pump, which squirts fuel into the manifold just behind the butterfly.<br /><br />Here is the cold start procedure I use on my 70 Force.<br /><br />1 Make sure fuel primer bulb is pumped firm.<br />2 Push the throttle control forward (half way) by using the throttle only button on the controls to disengage the shift mechanism.<br />3 Turn key to "on" position.<br />4 push key in for 3 seconds then turn key to start position. Don't hold the key in for too long, or you may flood the engine.
 

choskin

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Re: 1991 Force 70 Hp Hard to start when cold

Thanks Roscoe, i have located and removed the solenoid that pumps fuel directly into the carb.<br />it is open circuit, I shall replace it.<br />However I removed the rivets to check the solenoid coil and the coil was full of petrol<br />potential fire I think...<br />One further question , when you hold the key in<br />does the solenoid make a continuous clicking or does it click once for each key push?<br />I dont see anything to break the circuit so I initially suspected the solenoid would operate once with each key press.
 

roscoe

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Re: 1991 Force 70 Hp Hard to start when cold

Craig, I just don't know. There has been a few discussions of this question, and no concensus was reached.<br /><br />Some say it activates only once, but for how long will it inject fuel?<br />Others say it will continue to cycle.<br />Others say you have to push the key several times.<br /><br />I have a factory service manual, and it only instructs how to replace it. It does not say how it works. I am now curious, and will test mine when I remove my boat from storage in about a month.
 

choskin

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Re: 1991 Force 70 Hp Hard to start when cold

It is an interesting one, because I was told to hold the key switch in as you also said.<br />However my solenoid has cooked itself, melting the plastic housing that the fuel passes through.<br />this seems how the fuel ended up inside the solenoid coil housing.<br />I now wonder if the original design called for a short push on the key switch to cause the solenoid to operate once, pulsing a very small shot of fuel.<br />If this is true then holding the solenoid on for more than a few seconds could cause the pump to melt!<br />I got a price on a new one, outrageous,$US150.<br />Im going to look for another off a Mercury or Mariner, perhaps.
 

Peter J Fraser

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Re: 1991 Force 70 Hp Hard to start when cold

Craig11,<br />I have all the books you need for your engine. Seloc's & Clymer as well as an original owners manual for Force 70 hp.<br />I sold my boat last year but kept all the library from the dealer. You are welcome if you wish to contact me please do so. I am in Hamilton city<br />That coil holds the enrichment valve open continuously when the key is pressed in. As long as there is fuel under pressure in the delivery line from the pump to carb it will spray excess fuel into the carb throat. Not a choke as such but more like the coldstart injector found in modern EFI autos.<br />By the way I also have a surplus propellor for that engine.<br /><br />Regards<br /><br />Peter<br />Phone 027-4923674 or 07-8494779 evenings.
 

choskin

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Re: 1991 Force 70 Hp Hard to start when cold

Thanks peterf, my mother lives in Hamilton, So might visit you soon.<br />Propellor is interesting as the one I have has a few dings from previous owners.
 

baboon bum

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Re: 1991 Force 70 Hp Hard to start when cold

i find it starts best when <br />1/prime it hard<br />2/tilt engine right DOWN<br />3/put accelerator half way in<br />4/push in key and turn it at same time<br />mine starts 1st time even in minus 7 degrees
 

choskin

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Re: 1991 Force 70 Hp Hard to start when cold

Just to finish the story, and in appreciation to everyones help.<br />I managed to buy a used fuel solenoid from the local marine mechanic for $US15...<br />much better price but we shall see how long it lasts.<br />Now I have a working system and a motor that starts much easier I can confirm the operation.<br />when the solenoid is operated by pushing in the key start switch.<br />The solenoid clicks once, allowing presurised fuel from the carb float chamber to flow<br />through the solenoid to the inlet manifold.Thus priming the combustion chamber.<br />Peterf describes this.<br />Roscoe is correct to hold the key in while cranking for only 3 secs, or flooding of the carb<br />occurs. also 3 secs prevents the solenoid coil overheating.<br />The marine mechanic said if you are stuck out on the water with a motor that wont start,<br /> due to a faulty solenoid.<br />Place a hand over the carb air inlet while cranking, making the fuel mixture rich enough to<br />prime the combustion chamber.I haven't tried this but might be worth a try in a jam.
 

Peter J Fraser

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Re: 1991 Force 70 Hp Hard to start when cold

Ok Craig,<br />I spend a few days in Auckland ea month so either way we should catch up. Most weekends I am out of town at beach tho.<br /><br />Peter
 

jagreenall

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Re: 1991 Force 70 Hp Hard to start when cold

I am having a similar problem. I go through all of the procedures as listed above, but it is real hard to start. I called a boat repair place and they said to disconnect my battery from everything and run jumper cables directly to the starter and see if the starter cranks faster. I did so, and it did not change. He then said it was the starter as it should be cranking the starter faster. I bought a rebuilt starter off of ebay and installed it today. I have no change. I even pulled up my van and hooked jumper cables up to it and still the starter cranks really slow. Is this the way the starter is supposed to be, or is it supposed to be cranking faster?
 

roscoe

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Re: 1991 Force 70 Hp Hard to start when cold

jagreenall <br />It is almost always better to start a new topic when trying to solve an engine problem.<br />You should also list your make, model, year, or model number and serial numbers, so that the correct info can be passed on to you.<br /><br />It is hard to tell how fast your starter is spinning from here.<br /><br />Is this engine new to you?<br />Have you had the engine running at all?<br />Is this a new problem?<br />When did the problem start?<br />Have you checked all the wiring for corrosion and tightness? Particularly the ground wires.<br />Have you checked for spark?<br />Have you done a compression test?<br /><br />Its a good thing the engine did not start when you tried jumping it.<br /><br />A running outboard must always be connected to a battery, or you will burn up the voltage rectifier/regulator.<br /><br />If you can provide as much info as possible, maybe we can help you.
 

choskin

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Re: 1991 Force 70 Hp Hard to start when cold

My 1991 Force 70Hp cranks over fairly quickly,<br />How to describe the speed in a text message.<br />Aprox 2 revs per sec (just a guess really).<br />One idea I have with the slow cranking problem is to check there is no corrosion on the earth electrical connection to the power head chassis.<br />A high resistance earth connection will rob valuable volts to the starter motor.<br />My motor had corrosion around the earth connection. I attempted to unbolt the earth connection and snapped off the bolt, it was seized. So I recommend soaking the corroded connection in penetrating oil (WD-40, CRC etc)for a day first.<br />In my case I then connected the earth cable<br />(fat guage wire) to the mounting bolt for the starter motor. Better not to snap the bolt though.
 

kutai

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Jun 8, 2023
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My force 70 1991 easy to start on land but when out on the sea hard to start after half hour is it common but otherwise when running on the sea sweet as just need some info weather anyone come across this problem I've changed plugs if anyone's has some advice would be appreciated.
 

jerryjerry05

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Advice: #1 start your own thread. The one you brought up is 19 years old.
The mods gonna shut it down as soon as they see it.
You using the choke to restart?
 
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