Force 85 really difficult to start

marcus1802

Cadet
Joined
Oct 12, 2020
Messages
15
Hello everyone, im a new member in here, and also a beginner in boats. I have bought a 85 hp force (I don’t really know the year, but late 80’s I guess), which is incredibly difficult to get started. The previous owner had adjusted the timing and carburetors, but I’m not sure he have done it right. The problem is, that it won’t start. I’m keeping trying, but it takes op to 20 minutes.
The previous owner also said he had done a compression test, and that looked fine, and they were equal. The compression feels right too then it’s on (But there is a chance of he have lied to me, but as the good person I am, I trusted him, which sometimes is can be stupid). I have ordered new plugs, just so I know it isn’t there where the problem is.
Then today I got help from my cousin (that know a little more that me about engines), and we tried to start it in gear (and forced the little “in neutral” button, on), to give it a little gas. And then it started. Can I be because to trigger is placed different then or what can cause the problem. I will be so thankful to all kind of help 😀
 

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,240
Hello everyone, im a new member in here, and also a beginner in boats. I have bought a 85 hp force (I don’t really know the year, but late 80’s I guess), which is incredibly difficult to get started. The previous owner had adjusted the timing and carburetors, but I’m not sure he have done it right. The problem is, that it won’t start. I’m keeping trying, but it takes op to 20 minutes.
The previous owner also said he had done a compression test, and that looked fine, and they were equal. The compression feels right too then it’s on (But there is a chance of he have lied to me, but as the good person I am, I trusted him, which sometimes is can be stupid). I have ordered new plugs, just so I know it isn’t there where the problem is.
Then today I got help from my cousin (that know a little more that me about engines), and we tried to start it in gear (and forced the little “in neutral” button, on), to give it a little gas. And then it started. Can I be because to trigger is placed different then or what can cause the problem. I will be so thankful to all kind of help 😀
Welcome to Iboats,
The year is crucial to know to help you properly.
There's closed stickies at the top of this forum in the Force section that are very helpful; read them all

Get a compression gauge (never believe someone's word, when buying) verify if the are equal?? post the the results

It's quit normal for a cold motor not to start unless it's in warm-up mode after running it for let say 10 min, will it stay running when you switch back to low idle mode?

keep us posted
 

marcus1802

Cadet
Joined
Oct 12, 2020
Messages
15
Welcome to Iboats...
Can these pictures maybe help, to know a little more? Or I can take a picture of the serial number on it, that must indicate the year?
 

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The Force power

Commander
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If you still have a serial# sticker that is legible then you're lucky; most of them have faded away.
Yours is a '88 to '90
Inspect/replace the fuel-pump (a maintenance item)
Inspect all fuel-hoses/clamps
Do you have any "back firing" ?
 

marcus1802

Cadet
Joined
Oct 12, 2020
Messages
15
If you still have a serial# sticker that is legible then you're lucky; most of them have faded away.
Yours is a '88 to '90
Inspect/replace the fuel-pump (a maintenance item)
Inspect all fuel-hoses/clamps
Do you have any "back firing" ?

Nice to know what year it is. I think the fuel pump works as it should because the carburetor gets gas. When I hold a hand over the air intake, there comes a lot of gas out, so it is getting gas.
Backfire... It made a loud bang yesterday, suddenly, which I suppose was because of a lot of gas in the cylinder, but couldn't that be because of the timing. I don't know much about boat engines, and especially the changing of timing, but i remember years ago when working on 50cc moped engines, if the timing wasnt right, it couldnt start, and it maked a lot of loud bangs.
 
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jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
From the color scheme it's an 87.
You need to figure out the starting procedures???
#1 squeeze the ball until it gets hard, if it doesn't get hard, then the fuel pump
might need a rebuild??
#2 throttle advance, depending on the shifter, you either pull the handle out and push it forward, or push in a button then push it forward.
This helps pick up the rpms.
#3 Turn the key to start and as you turn it push in the key to activate the choke.
Hold the key in until the motor starts or coughs.
If it coughs, let the key come back out and just turn the motor over.
This should get the motor started. If it coughs, backfires, misses then
there's problems with the low speed air system.

The first 4-5 posts in this forum are tips and tricks for your motor.
Read ALL of them, there might be something there that you can use??

The backfire: from the 20 min. of trying to start the motor the gas builds
up and then explodes.

These motors should start within 10 seconds if the procedures are followed.

One more thing: I had a 8/85 that wouldn't start unless you used starting fluid.
By mistake I turned the key as it was tilted all the way up.
It actually started that way. Might be something to try if the other ways won't
work?
 

marcus1802

Cadet
Joined
Oct 12, 2020
Messages
15
From the color scheme it's an 87.
You need to figure out the starting procedures???
#1 squeeze the ball until it gets hard, if it doesn't get hard, then the fuel pump
might need a rebuild??
#2 throttle advance, depending on the shifter, you either pull the handle out and push it forward, or push in a button then push it forward.
This helps pick up the rpms.
#3 Turn the key to start and as you turn it push in the key to activate the choke.
Hold the key in until the motor starts or coughs.
If it coughs, let the key come back out and just turn the motor over.
This should get the motor started. If it coughs, backfires, misses then
there's problems with the low speed air system.

The first 4-5 posts in this forum are tips and tricks for your motor.
Read ALL of them, there might be something there that you can use??

The backfire: from the 20 min. of trying to start the motor the gas builds
up and then explodes.

These motors should start within 10 seconds if the procedures are followed.

One more thing: I had a 8/85 that wouldn't start unless you used starting fluid.
By mistake I turned the key as it was tilted all the way up.
It actually started that way. Might be something to try if the other ways won't
work?
Can it be because it has been transported in a trailer, laid down, so the gas in the carburetor ran into so it is drowned?

I squeeze it until it is hard, and that's working fine. I have tried to start both with and without choke. how do I adjust the idle?
 

Redbarron%%

Chief Petty Officer
Joined
Dec 7, 2017
Messages
479
If the starter is dragging the starting RPM may be too low to get to the coming in speed for the magneto to fire the plugs. Have you checked for spark?
For a quick check I use an induction timing light that at least proves that there is a strong current pulse to the plug. Check on all cylinders and while you are at it check timing as well.
 

marcus1802

Cadet
Joined
Oct 12, 2020
Messages
15
The starter works as I probably think it should, and I get a clearly good spark up to 10-12 mm, and I have just changed the spark plugs to be sure they wasn’t just old and tired. I think the next step is to buy a timing light gun, to check the timing is right. I began cleaning the carburetors today, but didn’t get it finished. How to adjust the idle? And how do I adjust the air intake adjustment (don’t know what the word is in English, or if it is right to say)?
Another question is. Is it real that it isn’t pumping water out when cold, because of the thermostat? I fought the pump was not working until I saw a video on YT, that shows the thermostat. I just need to be sure.
 

Redbarron%%

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Dec 7, 2017
Messages
479
Did you check the TDC on the flywheel vs the actual TDC measured by pulling #1 plug and check with a screwdriver against the top of the piston?
You may have sheared the flywheel key and the flywheel is out of sync with the crank.
I have seen boats scrapped and the engines torn almost all apart (except for the flywheel - no puller!) due to this.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
Look for the first 4-5 post in this forum.
One will have the procedure called a "link and sync"
That shows how to set the carbs up.
The air screw is set at 1 turn out on the 87/85
Check the flywheel key.
Do a compression test and spark check all 3 cyl.
 

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,240
Another question is. Is it real that it isn’t pumping water out when cold, because of the thermostat? I fought the pump was not working until I saw a video on YT, that shows the thermostat. I just need to be sure.
Water should be coming out of the "tell-tail" (if equipped with one) and out of the bottom regardless if thermostat is open or not
It may take 5 seconds with the initial start up to start flowing out
IF not the passage could be plugged OR the P/U tube not insert properly OR the Impeller is worn/missing/not turning
 

Redbarron%%

Chief Petty Officer
Joined
Dec 7, 2017
Messages
479
I saw above where the engine banged etc. I would check that the TDC mark is right as I said above. You seem to have fuel and the bang means that the timing is off.
Perhaps check the TCD on the #1 piston and the mark on the flywheel agree and then a little starting fluid sprayed into the air intake. It should at least hit and turn over if the timing is correct. Also check the timing when turning over with the starter. It should be around 9*.
One backfire and the key can shear... It ran and then it didn't, gets gas, turns over, we assume compression, suspect the key sheared enough to check.
 

marcus1802

Cadet
Joined
Oct 12, 2020
Messages
15
I saw above where the engine banged etc. I would check that the TDC mark is right as I said above. You seem to have fuel and the bang means that the timing is off.
Perhaps check the TCD on the #1 piston and the mark on the flywheel agree and then a little starting fluid sprayed into the air intake. It should at least hit and turn over if the timing is correct. Also check the timing when turning over with the starter. It should be around 9*.
One backfire and the key can shear... It ran and then it didn't, gets gas, turns over, we assume compression, suspect the key sheared enough to check.
I have now checked TDC, and it’s where it’s supposed to be. I mounted the carbs again after cleaning them. They were not bad at all, but to be sure. I also got some fresh gasoline, to be sure they weren’t anything wrong with that.
It made to loud bangs again, so I think that I will buy a timing gun tomorrow. I hope that’s my problem...
 

Redbarron%%

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Messages
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The bangs could have blown out the transfer gaskets on the side of the motor and you have a leak there now, but checking the timing is a very good idea. Also if you turn the motor to start it and then pull the plugs are they wet with fuel and oil? The plugs could be fouled as well, but the presence of fuel there would indicate that the engine is getting gas to the cylinders and you have seen spark and that leaves the timing of the spark and compression.
 

marcus1802

Cadet
Joined
Oct 12, 2020
Messages
15
The bangs could have blown out the transfer gaskets on the side of the motor and you have a leak there now, but checking the timing is a very good idea. Also if you turn the motor to start it and then pull the plugs are they wet with fuel and oil? The plugs could be fouled as well, but the presence of fuel there would indicate that the engine is getting gas to the cylinders and you have seen spark and that leaves the timing of the spark and compression.
The plugs are all totally new, and they sparks. Yes there could be a chance of a leak somewhere, but I don’t think it’s the problem since it wouldn’t start at the beginning before the bang (but it could have happened before I bought it).
I will buy the timing gun later, on my way home
 

Redbarron%%

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Dec 7, 2017
Messages
479
If it ran good and now you have this problem is one thing. If it is new to you then it's Katie bar the door.
Usually there is a single issue that suddenly causes the problem.
Banging or back firing is something out of time (often).
Make sure that the plugs are firing in the correct order.
#1 at the timing mark in the front at ~9*
#2 120* from there
#3 240* 'round back right side (looking at the engine from the front)
Something could have been swapped between cylinders.
That timing light is pretty necessary for one of these, not so much for the cars today with the computers etc.
 

marcus1802

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Oct 12, 2020
Messages
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So now i have tried the timing gun, and at full throttle, it is at the last mark. Is that right?
 

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The Force power

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So now i have tried the timing gun, and at full throttle, it is at the last mark. Is that right?

Static Timing is done in full throttle mode with @ Cranking-speed (spark plugs in + you'll have to bypass the neutral-switch or jump the starter-solenoid)
should be at 28 degrees ( to the right of center line)
 
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jerryjerry05

Supreme Mariner
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Messages
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Static timing is done with the plugs out and the wires grounded.
I made a 3 wire octopus for grounding the plug wires.
Timing marks L-R 28 30 32
 

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