Force 120HP Starting Problem

Hi everyone, I have a Force 120HP, early 90s model. Came with the Maxum line of boats. I don't have the serial #, but it's the black cowling cover, early 90s series. I'm sure you know.

Anyways, I'm having a problem with the starting of it. It will turn over and turn over and turn over, but will not fire and stay on. It will turn over like I said, do a quick sputter and then die. After a few of the sputters, it will continue to turn over when I try it, but nothing, until eventually I can hear the battery being drained and give up.

I have tried numerous things so far, but nothing has fixed the issue. Things I have done;

- new starter as of last summer (cleaned out the bushings, etc)
- new battery, fully charged, cleaned the poles, connections, filed them, etc

One thing I have been trying are different methods for starting it;

- not using the choke, and just turning the key
- choking (pushing in the key while turning it over), I can see the choke engaging so I know that's working
- playing with the throttle while attempting to start it, with the choke engaged, and without, but still nothing
- I have also tried having someone engage the choke manually while turning it over, and nothing, also tried priming the bulb while turning it over, and still nothing. I figured this would do it, and I can hear fuel being pumped into the engine, but for some reason I'm not getting it to fire

I was told by my mechanic that I should prime the bulb nice and tight, engage the choke and just turn it over until it finally fires. I have tried this and nothing. I don't want to keep doing it because I will burn out the starter and anything else involved with starting the engine.

Last year I adjusted the idle setting to bring up the rpms at idle speed. Do you think that may have had anything to do with the starting problem?

I haven't swapped out the spark plugs yet this year, but I will. I don't think this is the problem though. But I could be wrong.

What other things should I consider? Fuel pump, impeller, anything else?

Thanks in advance everyone, hopefully get this figured out soon!

EDIT: I've attached some pictures, just to clarify make and model.



Scott

Re: Force 120HP Starting Problem

Scott,

Are you sure the choke is working, you should hear the chock clicking when you depress the key, mine did the same thing, wouldn't start but once I lubed the chock and heard it clicking, it starting fine,

Re: Force 120HP Starting Problem

Hi SeaForce, thanks for the reply. I do hear the choke engaging / clicking, and I can see it engaging / clicking also. Perhaps it's not engaging far enough, I'm not sure. But it is in fact "choking".



Scott

Re: Force 120HP Starting Problem

on my 1996 120 I had problems starting it too. I was trying to start it like my merc with high idle, holding in the choke, etc. kept flooding it out and actted like your description.

the way I start it now is I keep it in neutral, no high idle, turn the 1 notch to right, push coke in for a quick second, release, then turn key further to right to crank. Works like a charm now.

Re: Force 120HP Starting Problem

Didnt you say you tried holding the choke closed and had someone else turn it over with no luck? If it is flooding then fuel isnt the problem. Have you checked to make sure it is getting spark to the plugs? If it is getting power to the plugs and your choke is working properly then that would leave it getting to much fuel I would think.

Re: Force 120HP Starting Problem

Thanks for the replies everyone. I have checked spark to the plugs and there is spark. If it is too much fuel coming in, hence flooding, how do I go about fixing that problem? Or where do I look?

Any ideas, thanks in advance!



Scott

Re: Force 120HP Starting Problem

Try keeping it in neutral (no fast idle), when you turn the key on, quickly push the key in and releae before cranking. don't keep the key pushed while cranking. see how that does for ya

Re: Force 120HP Starting Problem

I would start with the easy remedies first. You said you had changed the idle to raise the RPM’s. Was it running fine before you made that change? Did you change the idle when running or when engine was off? I only ask that because small changes to the idle screw will make big changes to the RPM. So I would back off on the idle screw and see if that helps getting it started. This is providing it is getting to much fuel and not too little. If it will sputter start I would try the carb adjustment.

Re: Force 120HP Starting Problem

Hi Kades, I made the adjustment on the idle last summer because it was idling too low and would conk out when put into gear at low idle. It may have affected the starting, but I'm not sure. Right now I would just like to get it fired up, then adjust the idle screw if need be.

Keep the replies coming guy, love this site, it's such a great help!

Could the fuel pump be the issue? I haven't touched it since I bought the boat 2 years ago.



Scott

Re: Force 120HP Starting Problem

Force are cold blooded. ARE YOU SURE you are using the Fast Idle (and choke) when cranking.
My 125 will never start if I don't pull the shift out and give it gas and choke first...even after sitting a hour or less..

Re: Force 120HP Starting Problem

Possible water in the fuel? I had the same problem more than once and each time it was water in the fuel. Some how water was getting into my tank through the vent or other means. I drained it and now i just use a portable tank since I have a old boat and it is not worth replaceing the 37 gallon mounted tank. Unhook the fuel line from the engine and squeeze the bulb and pump about a half gallon into a larg can and look for indications of water.

Re: Force 120HP Starting Problem

Great idea Ship, I'll try that.




Scott

Re: Force 120HP Starting Problem

You could have a few broken Reed Valves . If so check and see if they scarred your cylinders. If there is not too much damage I would have the Booysen Carbon Fiber valves installed . When they break they they will not do much damage . You can up your oil to about 3 oz / gal , this will help if you have a little scarring in your cylinders . . The Old Geezer

Re: Force 120HP Starting Problem

The Old Geezer said:

You could have a few broken Reed Valves . If so check and see if they scarred your cylinders. If there is not too much damage I would have the Booysen Carbon Fiber valves installed . When they break they they will not do much damage . You can up your oil to about 3 oz / gal , this will help if you have a little scarring in your cylinders . . The Old Geezer

Click to expand...

Probably not bad advice..but, the day I talk a Force apart for that...the parts are going ebay...not worth the effort to rebuild...

Re: Force 120HP Starting Problem

It is not that big a job . Take off the carbs. The valves are right on front of you . All you have to do is remove the old ones and install the new carbon valves . Use lock-tite on all screws and bolts when re-installing . Parts should be around $180.00 . I did this on my Force 120 and it runs like new .
You sure can't buy another one for the amount invested . The most important thing is to remove the spark plugs and have the walls of your cylinders checked for any scarring from the broken metal reeds going through . A little scarring can be over come by adding additional oil to you gas mix. Check you compression if it is close you are home free.
The Old Geezer

Re: Force 120HP Starting Problem

If it actually sputter then it's not likely but have you check the kill switch? I sat on the ramp once tried to crank the motor several time without success. I just happened to look down and the kill switch was pulled down. The culprit was the two years old who was in the boat with me the day before "watching" daddy prepping for the tournament. If switch is good then you're probably flooding it. Try give it a little gas when cranking but not a lot.

Re: Force 120HP Starting Problem

Thanks for all the information guys, absolutely love this site. I'm pretty sure it isn't the kill switch because I just turn the key to turn it off. There isn't a kill switch (that I know of). I will keep you all updated. Going to check out the carbs, water in the fuel, reed valves, etc.

Thanks again everyone!



Scott

Re: Force 120HP Starting Problem

NFA said:

Thanks for all the information guys, absolutely love this site. I'm pretty sure it isn't the kill switch because I just turn the key to turn it off. There isn't a kill switch (that I know of). I will keep you all updated. Going to check out the carbs, water in the fuel, reed valves, etc.

Thanks again everyone!



Scott

Click to expand...

If you do have one it should be right below or at least around the throttle. If you don't have one then I highly recommend you install one. Others on here will agree that it's a very important safety feature. If you get thrown out of the boat and there is no kill switch, your life jacket wouldn't do much good if the boat keep on going or it might circle back around and run you over. It could run into another boat or a number of other things that an un-piloted boat could do.

Re: Force 120HP Starting Problem

So an update for everyone, been a while.

After looking through a bunch of your suggestions, I finally brought the boat up to my mechanic. And the first thing he does is put his charger on my battery, and fire it up. Takes a sec, but it fires, and hums right along. He thinks my problem was simply that I wasn't charging the battery long enough. This holds true because I've only ever charged the battery overnight, at the longest. The mechanic says that I should charge it for about a week, once a month, to keep the charge up and strong. So fired it up at the mechanics', then ran it up to the lake. Ran it at WOT for a good hour, there and back, and ran like beautifully.

So now I'll put the battery on the charger and just leave it for a while, a good 5-7 days at least.

Thanks for all your advice everyone, anything else to consider, and keep an eye on, feel free to let me know.



Scott

Re: Force 120HP Starting Problem

NFA,

I had the exact same problem today. I started it fine the day before by submerging it in a bucket and I didn't realize I had the charger connected. Took it out to the lake today and it wouldn't fire up at all.

I got home, read your last post and hook it up again with the charger. Bam, first try and it started up.

Just in case if someone else is wondering if they had the same problem, I first thought the fuel filter was clogged because I hadn't gotten gas in over 3 years and it sat for a while. I thought getting gas kicked up all the sediments and clogged the filter. However, I knew that wasn't the problem by taking off the cover and tilted the motor all the way up and saw a bit of gas dripped out of the throttle bodies.

Anyways, just wanted to say thanks.