Need Help With Force Motor

[brianvolt7]

I have owned the boat for 3 years. Last year the motor turned over fine and ran perfect. Yesterday (9 mo. later) when attempting to start, it turned over great, just would not fire.

Motor: 1990 Force 120 on a 1990 Bayliner. 2 stroke.

Here is where I am at with troubleshooting:
All fuses are good
Has new plugs
I have full voltage at the starter and the motor turns
The overheat switch is open on the boat, though I believe this to only feed the buzzer (Orange)
The ignition switch start signal is normal (Yellow)
The choke is functioning (Green)
The ignition has full voltage (Red)
The emergency cut off switch is open and normal (White)
Shift cut off switch is closed and normal
All electrical seems to be in order
I have fuel at the carburetor
I have tried starter fluid and did not fire
I don?t seem to hear the popping of the exhaust when cranking
The gas is brand new, I drained the tank at the end of the season last year, about one gallon was left

I believe I have spark, when I removed the plug boot and cranked it I could here it pop when holding it near the plug, (maybe)

Is there a way without special tools to actually confirm spark? Or does anyone have ideas on what else this may be?

Is there any other cut off/safety switch that I may be missing?

Thanks for any help you can offer.

 

[pnwboat]

Re: Need Help With Force Motor

Double check all of your ground connections. There is a black ground wire that runs from the plate that the coils are mounted on to the engine block.

If you can get your hands on a spark tester, that may be helpful to verify spark.

If you have any of the "bullet" type electrical connections that pull apart, I would check each of those too.

You might also check the timing to see if there is a problem there.

 

[PaulO]

Re: Need Help With Force Motor

Pull the plugs out. Let them rest near the head so they earth to the head. Have someone visually confirm there is spark when you crank the engine.

If there is spark then fuel must not be getting from the carby to the cylinders. If that is the case I would use a cloth to completely cover the carby throat. This will absorb fuel should it run out the front of the carby orifice ( this will depend on the angle when mounted to transom) and start cranking for 5 turns say. If it doesn't fire visually confirm a wet throat in the carby. If that is not showing signs of fuel moisture maybe the needle valves are stuck in place from sitting too long?

Others may have there own remedies.

 

[brianvolt7]

Re: Need Help With Force Motor

Pnwboat- I found the ground connection and it is solid. I tugged on all of the lugs that are on the engine block terminal strips and they all seem good. There were 4 connections similar to bullet but they were twist lock, one for each coil and they were good.

PaulO- I pulled all 4 plugs , one at a time and had my son crank the motor. Each plug sparked to the head. I confirmed fuel at the carb, my concern is that it is running out of the front though I have the motor trimmed down as far as it will go. I did try the starter fluid again sprayed into the carb with no luck. Also there was signs yesterday that the fuel was making it to the chamber, as I flooded it by choking, the plugs were soaked. This is not the case today though.

Thank you both, any other ideas?

 

[Newbie@boats]

Re: Need Help With Force Motor

They make a spark tester, you put it in the coil, and clip it to ground.

You can usually hear the clicking noise, but try to visually comfirm it, also there is like a saftey thing next to the steering wheel make sure thats clipped in.

 

[PaulO]

Re: Need Help With Force Motor

Well you need three things to make a fire, air, fuel and a heat source. It appears you have all of them.

Yes you do need to be careful of the excess fuel running out of the carby hence the rag.

Try and squirt a bit of fuel into each cylinder then give it a crank. If it fires then something maybe going on between the carbs and the cylinders- crap formed on the reeds, hole in the exhaust plate watering things down? Regardless how weak the spark is it should give some result provided the spark was continuous during the cranking phase.

Do a compression test too. If you don't have compression you are not drawing fuel into the cylinder.

It sounds like the engine has been sitting for a while and this is the first start for the season?

 

[pnwboat]

Re: Need Help With Force Motor

Seems odd that you have spark but no backfiring or anything. Couple of questions.

1. What type of ignition system do you have. Does it have a "switch box" or does it have the blue CD modules/coils?

2. What type of choke system do your carbs have? Is it the type with a butterfly, or does it have a fuel enrichment solenoid?

3. Have you tried to start it with the throttle in the "neutral fast idle" position?

 

[brianvolt7]

Re: Need Help With Force Motor

I will try the fuel into each cylinder then starting, it is the first start of the season.

I have the blue modules for the ignition. The choke system is the butterfly, they close when I push the key in. I am not sure how to set the gear/throttle lever for fast idle neutral. What are the steps?

I will try all of this tonight when I get home from work.

 

[pnwboat]

Re: Need Help With Force Motor

To engage the neutral fast idle position, pull the throttle handle out towards the center of the boat. The handle should come out about a 1/4 of and inch. Sometimes there is a button located on the center pivot point of the throttle handle you have to push to release the throttle. While the handle is out, push the throttle forward. This will allow you to start the motor while the throttle is advanced opening the throttle plates on the carbs. It's very easy to flood the carbs. Engaging the neutral fast idle position allows more air to help overcome a flooded condition. I use this position every time I start my motor on a regular basis. I also never engage the choke more than 2 or 3 seconds at a time.

 

[brianvolt7]

Re: Need Help With Force Motor

OK, so I have put it into high idol, by hand at the motor. The advanced throttle does not function. It will pull out but when you push it forward it only goes about a quart of the way and does not activate the valves. I have never had to use this to start it, one more thing to fix.

I held my hand over one of the carbs and held the valves wide open. I actually got some pops like it was ready to start. I sprayed starter fluid and ultimately overheated my starter. It just gave up so I will try again in a couple of days.

I am considering paddling to the center of the lake, pulling the plug and swimming back.

 

[PaulO]

Re: Need Help With Force Motor

Brianvolt

That's good to hear. It means you are inches away from snatching victory from the jaws of defeat and a little more perseverance will see you conquer all

I found with my 120 timing (I did follow the book to the best of my ability) the link and sync made me come to the conclusion that anywhere upto fast idle will only alter the timing. Once the engine is in gear and the trigger is BTDC then the throttle valves start to open. If I am wrong in my setup then someone please set me straight. I have had the motor running and in neutral the increase in RPM is only attributable to the change in timing.

P.s. -Don't run the starter for extended periods. 15 secs at a time is mentioned somewhere in clymers. Try a bit more fuel than you did last time.

This is dangerous but you could wrap some fuse wire around both the ignition microswitch terminals to by-pass the safety start in neutral only. That could allow you to open the throttles a bit and get better airflow and atomisation of fuel while cranking. Be careful with the prop and people or animals and make sure you got water into the lower leg.

Or

Maybe squirt some compressed air directly into one of the carby throats to achieve the same?

 

[pnwboat]

Re: Need Help With Force Motor

Do you have a timing light?

 

[PaulO]

Re: Need Help With Force Motor

Who me? Yeah. It was set with Butterfly valves horizontal at 32? BTDC manual cranking.

Prior to me taking possession the timing was set at approx 40? BTDC and the throttles were only 3/4 open although there is not much difference between that and full throttle timing wise. It was way out and is probably what caused the bottom piston to detonate and melt. All fixed now.

Just looking at the trigger position I would guess it is 5? ATDC in the idle position and rotates to 5? BTDC in the high idle position give or take a few degrees. The book did say timing is not important at low RPM it is WOT that is the important one.

 

[pnwboat]

Re: Need Help With Force Motor

Sorry for the confusion PaulO. My apologies. I meant to direct my question regarding the timing light to Brianvolt7.

Brianvolt7, do you have a timing light?

Note PaulO's statement about being close to determining what might be wrong with your motor. Don't lose faith!

 

[brianvolt7]

Re: Need Help With Force Motor

Guys,

I dont have a timing light, i will need to pick one up this weekend. I did not try to start last night, just sat in the boat with my wife and daughter drinking a couple of beers and talked about how great its going to be to be back on the water again. I am going to try to start it again tonight again.

 

[pnwboat]

Re: Need Help With Force Motor

Need a timing light just to make sure it's firing when it's supposed to. Also need to verify that it's got good spark. Make sure all of the ground wires for the ignition system are making good contact. There is a ground wire for each coil and one that goes from the coil mounting plate to the engine block. You should also have either two white wires or two black/yellow wires that go from the CD modules to the terminal strip on the opposite side of the block. Depends on what year as far as color code. Try disconnecting the two wires to see if she fires. This is the kill circuit. By disconnecting the wires, you eliminate the kill circuit. If it does fire, you can kill the motor by engaging the choke.

 

[brianvolt7]

Re: Need Help With Force Motor

OK, got home about an hour ago from work and started to work on the boat. Now the starter only turns the motor one revelution and then stops then starts for one rev and stops. I am sure I have plenty of battery. Is my starter bad?

Maybe instead of pulling the plug in the middle of the lake I should save the trip and put a hole in the block, say about 9mm in diameter.

 

[PaulO]

Re: Need Help With Force Motor

It sounds like not enough current getting to the starter??? Make sure all earth points are secure and clean.

Put a volt meter across the + and - of the battery and note reading when turning over the starter. If it is less than 9.6volt during cranking the battery may have issues.

 

[brianvolt7]

Re: Need Help With Force Motor

I cleaned all of the grounds and positives last weekend so I am sure that they are clean. I put the battery from my car into it to make sure it was not my battery. It does the same thing. Something else I noticed was that it got extremely hot to the touch even after cranking only a few times. Is there a way that I can test the starter to see if it is good? I know the starter was a used one the the previous owner had just put in before I bought the boat a few years back.

 

[brianvolt7]

Re: Need Help With Force Motor

Guys,

I pulled apart my starter this morning to find the ground wires to the brushes charcoaled, I cleaned the brushes and all of the contacts. The starter cranked much better but not for long, it is now back to its 1 on 1 off. I ordered a new starter should be here by Thursday. In the meantime I have cleaned all of the connectections to the coils. I did try removing the kill wires with no luck starting. Is there a way to tell if all of the modules are good?