Need Help With Force Motor

[pnwboat]

Re: Need Help With Force Motor

Stator checks out fine. I have to ask, are the plug wires on correctly? Spark plug wire for the upper most coil should go to the upper most spark plug, and so on down the line. Plug wire from bottom coil goes to bottom plug.

 

[brianvolt7]

Re: Need Help With Force Motor

Yes, this is the way they are plugged in. Do you think it may be the blue modules?

 

[pnwboat]

Re: Need Help With Force Motor

It may be but, you did get it to run briefly at one point by squirting gas into the cylinders. This tells me that the plugs were firing. The stator checks out OK. The CD Modules are pretty pricey.

I think you still need to do two tests. Compression and timing. Autozone will loan you the tools for a refundable security fee once you return the tool.

A note on using starting fluid. On all 2 stroke motors, the roller bearings on the crankshaft and rods get their lubrication from the oil that is mixed in with the gas. Starting fluid has a tendency to wash the oil away.

 

[pnwboat]

Re: Need Help With Force Motor

Just thought of one other thing. Disconnect the two green/yellow wires that go to your rectifier. Put some tape on them to insulate them. Try starting the motor and see what happens.

 

[brianvolt7]

Re: Need Help With Force Motor

I will try this first thing in the morning.

 

[brianvolt7]

Re: Need Help With Force Motor

Almost there!!!! I disconnected those two green lines and the motor turned over an ran for 8 to 10 seconds.

Here were the conditions: After about 3 15 second bursts of starter, WOT, cranking about 10 seconds, choked and POW, it started and ran. Purred like a kitten, just like it did last year.
It started and ramped up quickly to match the full throttle and then it ramped down and died. Almost like it ran out of fuel
After that it would not start but you could here if firing with the starter engaged and cranking and on full choke and smoke coming out of the exhaust. Several loud pops as well.
It would not attempt to start unless I was on full choke and WOT in gear.

Do you think part of the problem is the rectifier?

 

[brianvolt7]

Re: Need Help With Force Motor

pnwboat,
I am going to pick up a timing light and compression tester on Friday (payday). Will I need to have the engine running to check the timing?

 

[pnwboat]

Re: Need Help With Force Motor

Yes, I suspect that the rectifier may be toasted. You can pick one up at Radio Shack. 25 amp full bridge rectifier. Should be less than 5 bucks. You can check it with your meter. I have to look at one closely to see exactly how to test it. To set the timing, you use the static method which means you do not actually start the motor.

I think you may have more than one problem here. Ignition and fuel supply issue. We can tackle one problem at a time. The motor should have kept running and not died. Also want to make sure you have water going to the motor to keep from damaging the water pump impeller.

 

[brianvolt7]

Re: Need Help With Force Motor

Yes, I run the water through the cups each time I start it. It also has a new impeller and gasket kit.

Other than the rectifier, what do you think the next step would be.

 

[maxum_man]

Re: Need Help With Force Motor

Yes, I suspect that the rectifier may be toasted. You can pick one up at Radio Shack. 25 amp full bridge rectifier. Should be less than 5 bucks. You can check it with your meter. I have to look at one closely to see exactly how to test it. To set the timing, you use the static method which means you do not actually start the motor.

I think you may have more than one problem here. Ignition and fuel supply issue. We can tackle one problem at a time. The motor should have kept running and not died. Also want to make sure you have water going to the motor to keep from damaging the water pump impeller.

I don't mean to hijack the forum, but do you have a PN for the 25 amp full bridge rectifier? I need a new one too and I don't wanna pay $125 for one from boats.net!

Also, I think the fuel problem lies within the Carbs. A good disassembly, soaking, and new needles and seats might do wonders!!

Bryan

 

[brianvolt7]

Re: Need Help With Force Motor

Maxum Man,

I found a universal Force for $10 + 5 shipping and handling on ebay. Just need to replace the ring connectors with push on terminals. It is a CDI 152-9209.

 

[maxum_man]

Re: Need Help With Force Motor

Will a universal 20 Amp rectifier work on a 18 amp system? I don't know much about electronics.

 

[pnwboat]

Re: Need Help With Force Motor

Maxum Man.. Yes a universal bridge rectifier will work. Personally I would prefer something a little more robust than just 20 AMPs for an 18 AMP system. At least 25 AMPs, but a 20 will work. Just to make sure, do you have a picture of your original or what year, HP and S/N is on your motor?

P/N for the Radio Shack version is 276-1185. $3.29. Rated at 25 AMPs 50V.

 

[brianvolt7]

Re: Need Help With Force Motor

pnwboat,

Do you think I should do something with the carbs?

 

[pnwboat]

Re: Need Help With Force Motor

I think that you should at least confirm the float level. To really do it correctly, you need to take the carburetors off. Remove the fuel bowls and flip the carb upside down and see how the float sits in relation to the casting. Below is an illustration of how the float should sit.


Also while the carb is off, clean out all of the small passages with some pressurized carb cleaner. The type of can that has the small extension tube to get to the small passages in the carburetor throat etc.

 

[pnwboat]

Re: Need Help With Force Motor

One other note to Maxum-man. The reason I mentioned that we need the model, HP, year and S/N is that I believe that you need a rectifier/regulator. I just realized that you said a replacement was $125.00. That probably means you have a rectifier/regulator. There is a difference between a rectifier and a rectifier/regulator. If you have the rectifier/regulator set up, then a universal rectifier will not work. There is a sticky at the top of the forum titled "if you have high charge voltage" that goes over the use of a universal rectifier/regulator.

 

[maxum_man]

Re: Need Help With Force Motor

oh ok. I am pretty sure thats what I have. I'm sure glad you posted that before I went and fried something!! Thanks!

 

[pnwboat]

Re: Need Help With Force Motor

Maxum_man, sorry I wasn't clear about that in the first place. Thought I'd double check to make sure. Sent you a PM.

 

[brianvolt7]

Re: Need Help With Force Motor

pnwboat,

I will remove the carbs tonight. I have some carb cleaner that I picked up at Autozone that came with a little straw. Do I need to remove any of the small screws or needles on the carb and if I do, is there a certain setting or adjustment that I need to follow when reinstalling?

 

[pnwboat]

Re: Need Help With Force Motor

I would remove the idle mixture adjustment screw #15 and plug #8 (it's usually plastic) in the diagram below. Before you remove #15, turn it in to see how many turns it goes before it bottoms out. Don't force it. Make a note of how many turns. Clean those passages out real good. Also make sure the fuel inlet passage to the carb where the needle valve sits is not obstructed. Any other small holes or passages that you see. Once you put it back together, screw the idle mixture screw in until it stops. Loosen it up based on the number of turns you noted earlier. Should be somewhere around 1 - 1 1/2 turns out from lightly seated.

http://www.boats.net/parts/search/Merc2/Force/120%20H.P.%20%281990-1994%29/0E000001%20THRU%200E093699/CARBURETOR%20%2890A%2C92C%29/parts.html#

You have to check the float per my previous post. Adjust if necessary.

Once you put the carbs back on, you will have to adjust the tie bar that connects both carburetors. The tie bar operates the butterfly valves in both barbs. The butterflies in both barbs have to be in perfect sync. Also you don't want any play that will allow one butterfly to open before the other. Takes a little tinkering to get it adjusted but it's not difficult.

To adjust the idle mixture, start the motor. Crack the throttle wide open for a split second. If the motor just dies right off, the the mixture is probably too lean. Turn the screw out 1/8 of a turn, start motor let it settle in and try again. If the motor kind of bogs and then slowly picks up when you crack the throttle open, then it's probably too rich. Turn the screw in 1/8 of a turn and try again. These carburetors do not have an accelerator pump in them like automotive type carbs. Getting the idle mixture adjusted for good throttle response is a little trickier. Do not adjust the idle mixture less than than 7/8 turn out from lightly seated. This is too lean which may cause engine damage. The final test will be once you're out on the water. Re-adjust if necessary.