1997 Force 120 timing

[fishngolf]

I recently purchased a boat with a 1997 Force 120 outboard. The previous owner said that he had lost power at the end of last season and hadn't had the time to get it running this season. The first thing I did was check the compression and all cylinders which checked out fine. Put new spark plugs in and after a little bit got the motor running. Problem I am having now is the second cylinder is not firing correctly. I changed the wires and the cdm module with cylinder 1 but still no change. Cylinder 4 is not 100% either which makes me think its timing related. I'm in the process of replacing the stator and trigger but was wondering if anyone knew if it might be something different. Any help or input would be appreciated. Trying to get it in the water this season.

 

[Jiggz]

Re: 1997 Force 120 timing

Personally, I would troubleshoot for sure before changing expensive items like CDM's, stator and trigger units. Since #2 and #4 cylinders are fed from different CDM's it's possible the cause is mainly to trigger signals being weak or not present. The stator should be good as it provides the same power to #1 and #2 and also to #3 and #4. Meaning if #1 is firing, then stator power going to CDM feeding #1 and #2 is good. Likewise with #3 and #4.

Timing doesn't usually change unless messed up with. I'll focus on the trigger signal which you can check by voltage reading going on CDM's feeding #2 and #4 . This voltage is really low. Verify also the wires are not switched around and also the plug wires. Do you have a wiring diagram to go by? Lastly, it is not unusual wire connectors for the trigger wires to scale and cause this problems. Clean the connections and check the wires to make sure they are not rubbing against ground.

 

[jerryjerry05]

Re: 1997 Force 120 timing

I think the 97/120 only has 1 pack.
In 94 they used 2 systems the old with 2 pack and the later motors with 1 pack.
Get the FACTORY manual and do the tests.
CDI ignition and outboard ignition . com (remove spaces) both have test procedures for your motor.

Like Jiggz says the timing won't change unless you change it.
Make sure the connections are all good.
I routinely change all connectors on my repairs.
They are shrink wrapped and can be broken under the wrap.

 

[fishngolf]

Re: 1997 Force 120 timing

Thanks for the input. I'll go through and check all the connectors tonight. Unfortunately I don't have a wiring diagram. Let me know if there's one available somewhere.

 

[jerryjerry05]

Re: 1997 Force 120 timing

Not sure the wiring diagram is on the block.
It was on the older models.

Take pics and mark all the wires.Or you'll be in serious hurt.

Profile/location?
You might be close to someone who can help.

 

[fishngolf]

Re: 1997 Force 120 timing

Replaced the starter and trigger and no improvement. Looking at the reeds next. Anybody know where I can find some for this particular motor?

 

[jerryjerry05]

Re: 1997 Force 120 timing

Inspect the reeds before you buy.Post some pics.
99.99% of the time reeds don't go bad unless you have a BAD backfire problem.

Check the fuel pump system.Water in the fuel?

Plugs burning how?Water on the plugs?

 

[fishngolf]

Re: 1997 Force 120 timing



Started up after new stator and trigger. Ran real good then mechanic checked primer bulb and boom big backfire. Here is a picture of the reeds after the backfire.

 

[fishngolf]

Re: 1997 Force 120 broken reeds

Re: 1997 Force 120 broken reeds



Anyone ever use boyesen reeds with this motor? Debating whether to order the factory replacement $85x4 or go with the boyesen kit for $125.

 

[pnwboat]

Re: 1997 Force 120 broken reeds

Re: 1997 Force 120 broken reeds

I may be mistaken, but I don't think Boyesen makes a set for a 1997 120HP. They only go up to 1992.

Here is another place that makes them. Might want to give them a call. Chris Carson Marine Service

http://www.ebay.com/itm/Force-Sport-Outboard-Reed-Reeds-100-140-hp-1993-up-CCMS-/280703548384?pt=Boat_Parts_Accessories_Gear&hash=item415b3c3be0&vxp=mtr

 

[jerryjerry05]

Re: 1997 Force 120 broken reeds

Re: 1997 Force 120 broken reeds

Jiggz I was wrong on the packs on the 97.They use 4 CDM's One for each cylinder.

Guess it's time to go back to school!!!

 

[fishngolf]

Re: 1997 Force 120 broken reeds

Re: 1997 Force 120 broken reeds

ordered some boyesen b244. They are the correct ones for the 97 i'm told. Anyone know what the correct timing is for this motor at idle. Mechanic set it to 22 degrees is that right?

 

[jerryjerry05]

Re: 1997 Force 120 broken reeds

Re: 1997 Force 120 broken reeds

Timing shouldn't be set at idle.
It needs to be static timed or dynamic timed.
Static is not running dynamic is running at WOT.
32deg See top post for instructions.

 

[fishngolf]

Re: 1997 Force 120 broken reeds

Re: 1997 Force 120 broken reeds

Put in new reeds on cylinders 1 and 2. Runs but seems that cylinders 1 and 2 only fire at WOT. Any suggestions?

 

[jerryjerry05]

Re: 1997 Force 120 broken reeds

Re: 1997 Force 120 broken reeds

You getting fire at all time or just at WOT?
In-line sparkies and start it up.
Anyone do a compression test?
What's the readings?

 

[fishngolf]

Re: 1997 Force 120 broken reeds

Re: 1997 Force 120 broken reeds

Compression is 150 on all cylinders +/-2 on all cylinders. Mechanic is convinced one and two arent firing cause when he pulls either there is very little if not any change. When he pulls three the engine almost dies. I think 3 controls the water pump so that should make sense though right? I originally put in the Boyesen reeds with the factory throttle restricters. Their directions say just to use their rerstricters which is only a small bar going across where the screws are. I tooke the reeds out again and but in the boyesen restricter and now i think I have it. started up and at idle if i pull 1,2, or 4 there is very little change. I pull three the engine dies. If I pull 1+2 engine dies. This must mean that 1+2 are in deed firing right?

 

[fishngolf]

Re: 1997 Force 120 broken reeds

Re: 1997 Force 120 broken reeds

 

[fishngolf]

Re: 1997 Force 120 broken reeds

Re: 1997 Force 120 broken reeds

Any input on whether I should replace the stock reeds in 3+4 to match the new boyesen I've put in 1 + 2?

 

[fishngolf]

Re: 1997 Force 120 broken reeds

Re: 1997 Force 120 broken reeds

Just pulled the reed plate for 3 and 4 and found another broken pedal on 4.



Hopefully this solves my idle issue.

 

[TwoFish]

Re: 1997 Force 120 broken reeds

Re: 1997 Force 120 broken reeds

Man that motor has been tough on the reeds! How many hours has it done?

I’ll be interested to see what you think of the Boyesen reeds. I have a 1998 75 and the reeds don’t close properly so need replacing. I am looking at getting a set as well.