89 Force 125 not running on 1 & 2

[thelmuth]

I have been searching the forums for a situation like mine to no avail. I have a 1989 Force 125 with little to no power from cylinders 1 & 2. Strong spark on all cylinders. Compression 140 - 145 on all. Mixture screw does not affect at all until completely closed then RPM only drops slightly. DVA voltage running: Stator - 206 & 208, Triggers .62 - .84

Now the history. Owned this boat for 3 years. Never able to get above 4300 RPM @ 30 knots. 19 pitch prop. Spun the hub so I thought this is as good a time as any to try a lower pitch. Purchased a 17 pitch and had no difference in RPM or top speed, may even be a little less.

Decided to investigate further. Found a parts motor on Craigslist with a bad cylinder but all parts there. Seller said it ran good before it lost compression. Swapped out the entire coil/CDI assy. after replacing all the horshoe ends as well as the stator and trigger. The ohm readings on one leg of my old trigger was slightly low so I swapped both while I had the flywheel off. I have been playing musical parts with coils, CDI units and even swapped the top carburetor.

Earlier this year I replaced the plugs, performed a link n sync and adjusted the carbs. The top carb did make a difference when adjusted then but I don't think I was getting full power from those cylinders then either.

I am at a loss.

 

[Jiggz]

Re: 89 Force 125 not running on 1 & 2

Your dilemma is quite interesting. For starter I will check the following:
1. Reeds for the upper two cylinders
2. Timing
3. Fuel recirc system reeds between #1 & #2 cylinder
4. Intake side cover gaskets

 

[jerryjerry05]

Re: 89 Force 125 not running on 1 & 2

What boat?Size?
Possible the foam is waterlogged??
Boat/motor original package?
Snout on the lower unit?

Plugs burning right?Pics?
You sure the tachs reading right?

 

[emoney]

Re: 89 Force 125 not running on 1 & 2

What leads you to believe you don't have much power on the top two cylinders?

 

[oxmax360]

Re: 89 Force 125 not running on 1 & 2

i would throw the dart at a new set of plugs 1st, sometimes plugs are brunt quick on outboards.

 

[thelmuth]

Re: 89 Force 125 not running on 1 & 2

Your dilemma is quite interesting. For starter I will check the following:
1. Reeds for the upper two cylinders
2. Timing
3. Fuel recirc system reeds between #1 & #2 cylinder
4. Intake side cover gaskets

Reed valves are good and timing is correct. I checked it again after replacing the stator and trigger. Not sure what you mean by fuel recirc reeds. Have not checked the side cover gaskets but will look at them tomorrow night.

 

[thelmuth]

Re: 89 Force 125 not running on 1 & 2

What boat?Size?
Possible the foam is waterlogged??
Boat/motor original package?
Snout on the lower unit?

Plugs burning right?Pics?
You sure the tachs reading right?

1989 Cobia 194xl original motor. I suppose it's possible the foam is waterlogged which could account for top end performance but not rough idle and no power from 1 & 2. The plugs don't seem to look right (too clean) sorry no pics right now. But I have swapped holes as well as replaced them with other plugs, no difference. I verified the tach against my fluke inductive. Don't know what you are asking about the snout.

 

[thelmuth]

Re: 89 Force 125 not running on 1 & 2

What leads you to believe you don't have much power on the top two cylinders?

Power balance test. Little to no change in engine running when killing spark on ! & 2. Significant change on 3 & 4.

 

[thelmuth]

Re: 89 Force 125 not running on 1 & 2

i would throw the dart at a new set of plugs 1st, sometimes plugs are brunt quick on outboards.

Did change the plugs this spring and have swapped holes as well as used some other plugs with no change in operation.

 

[emoney]

Re: 89 Force 125 not running on 1 & 2

If you pull the carbs off, you should be able to see the Reeds. They can break or chip. Boysen sells replacements, btw, because somebody just the other day had this problem.

 

[jerryjerry05]

Re: 89 Force 125 not running on 1 & 2

Sorry answered the wrong question on your thread.

Like the others suggests,check the reeds.
Clean the carbs.
Check the fuel recirc system.
Get inline sparkies,test while running?
Possible it's dropping fire above idle.
Plugs,any water on them?
The exhaust snout on the bottom of the lower unit.

The connectors on the stator,trigger and packs.They can go bad.
Under the shrinkwrap the connection is broken.
Had this happen to me on a 125 I was working on and one of my 85's

 

[Jiggz]

Re: 89 Force 125 not running on 1 & 2

Reed valves are good and timing is correct. I checked it again after replacing the stator and trigger. Not sure what you mean by fuel recirc reeds. Have not checked the side cover gaskets but will look at them tomorrow night.

There are two fuel recirc reeds one for each set of cylinders, i.e. top and bottom sets or between 1 & 2 and 3 & 4. Their function is to suck out unburned fuel from each bottom cylinder (2 & 4) in the set into the top cylinders (1 & 2). It acts like a check valve wherein air can only flow on way from the bottom cylinder into the top cylinder. If the reeds are faulty, it allows free movement of air-fuel mixture between the two cylinders. This will not show in the compression test as the compression will still be good but the problem there is less amount of fresh air-fuel mixture entering the cylinders hence, lesser power, if any.

The easiest test is to disconnect the hose (a fuel hose actually connects the two ports) from the top cylinder. Blow into it and it should be blocked by the reeds. If you can blow into it the reeds needs replacement or fixing.

The main reeds exhibit the same symptoms. You cannot verify the integrity of the main reeds through compression test as other people tend to believe. Even with leaky reeds, compression test will still be good but power will be gone due to lack of fresh air-fuel mixture entering the affected cylinders. Remember, these two strokers are ported hence exhaust is only pushed out by introduction of fresh air-fuel mixture in the right volume maintained by the reeds both main and fuel recirc reeds.

 

[thelmuth]

Re: 89 Force 125 not running on 1 & 2

There are two fuel recirc reeds one for each set of cylinders, i.e. top and bottom sets or between 1 & 2 and 3 & 4. Their function is to suck out unburned fuel from each bottom cylinder (2 & 4) in the set into the top cylinders (1 & 2). It acts like a check valve wherein air can only flow on way from the bottom cylinder into the top cylinder. If the reeds are faulty, it allows free movement of air-fuel mixture between the two cylinders. This will not show in the compression test as the compression will still be good but the problem there is less amount of fresh air-fuel mixture entering the cylinders hence, lesser power, if any.

The easiest test is to disconnect the hose (a fuel hose actually connects the two ports) from the top cylinder. Blow into it and it should be blocked by the reeds. If you can blow into it the reeds needs replacement or fixing.

The main reeds exhibit the same symptoms. You cannot verify the integrity of the main reeds through compression test as other people tend to believe. Even with leaky reeds, compression test will still be good but power will be gone due to lack of fresh air-fuel mixture entering the affected cylinders. Remember, these two strokers are ported hence exhaust is only pushed out by introduction of fresh air-fuel mixture in the right volume maintained by the reeds both main and fuel recirc reeds.

I checked the fuel recirc system last night and found the check valve at #2 cyl. bad. I replaced it with parts from my spare motor (tested good). No noticeable difference in performance. Then for grins I swapped plugs in holes again and the miss followed the plug this time. Now#4 not firing 1 & 2 still not great, but actually doing something. Picked up a new set of plugs on my way home. Will install them later this evening.

While I had the plugs out I rechecked compression, 140, 140, 150, 145.

I pulled the reeds out the other day when i had the carb off. They are good.

I will be replacing all the coils after I am sure there is no other major issue. I am not one to throw parts at a problem hoping to fix it. I like knowing for sure what is wrong before spending money on parts.

I was hoping that the parts motor I bought would have had all good electronics but it didn't. 2 of the coils had the power lead break at the back of the coil and 1 of the CDI packs is bad. The stator and trigger are good though. I am limited as to how much $ I can/will spend on this motor. For little more than the cost of all the ignition parts new I can pick up a running Mercury or Johnson.

 

[thelmuth]

Re: 89 Force 125 not running on 1 & 2

Sorry answered the wrong question on your thread.

Like the others suggests,check the reeds.
Clean the carbs.
Check the fuel recirc system.
Get inline sparkies,test while running?
Possible it's dropping fire above idle.
Plugs,any water on them?
The exhaust snout on the bottom of the lower unit.

The connectors on the stator,trigger and packs.They can go bad.
Under the shrinkwrap the connection is broken.
Had this happen to me on a 125 I was working on and one of my 85's

I had some connections go bad while we were in the Keys in July. I have replaced every horseshoe connector on the ignition system. Most of them broke off way too easy.

Last night I determined I had spark plug problems. The miss followed the plug when swapping holes. I swear it didn't do that before, Grrr! Bought a new set on the way home and will install them later. Hoping that will help enough to go for a water test.

I did clean the carb, although that doesn't mean there is not a problem with it, but I did try a different carb without any improvement.

The reeds are good. There was a problem with the recirc system which I remedied.

 

[Jiggz]

Re: 89 Force 125 not running on 1 & 2

Well, I hope the new plugs will resolve your dilemma. I cannot think of anything else that can cause lower compression on the top cylinders hence lower power. But what is puzzling is they both have the same comp pressure which leads me to believe something else is allowing sharing of air-fuel mixture between the two cylinders. Of course, it is not unusual to have all cylinders register the same comp pressure.

 

[oxmax360]

Re: 89 Force 125 not running on 1 & 2

I was thinking plugs, I bought a set brand new and had one go bad almost right away spent days trying to figure it out, hope that fixes your problem good luck.

 

[thelmuth]

Re: 89 Force 125 not running on 1 & 2

Changed the plugs. That solved part of the problem but still not right. So I decided to try a different combination of CDI packs. Then it wouldn't shut off. So, I swapped one back in to see if it would kill. No, UGGH. Turns out the main ground from the mounting plate to engine broke in the process, which is why it wouldn't kill. Everywhere I turn other things pop up making it difficult to follow any logical diagnostic process.

Got frustrated and walked away. May mess with it later today or set it on fire. Not sure yet.

 

[oxmax360]

Re: 89 Force 125 not running on 1 & 2

Just try and work trough it when you get it right you will fall back in love with the force motor, I know it is a pain right now but when you fix that ground check all the grounds under the coils make sure they good and tight, I had one with a little rust on it caused it not to ground properly and when I cleaned it bam strong fire, good luck man I hope the force is with you this time.

 

[Jiggz]

Re: 89 Force 125 not running on 1 & 2

Changed the plugs. That solved part of the problem but still not right. So I decided to try a different combination of CDI packs. Then it wouldn't shut off. So, I swapped one back in to see if it would kill. No, UGGH. Turns out the main ground from the mounting plate to engine broke in the process, which is why it wouldn't kill. Everywhere I turn other things pop up making it difficult to follow any logical diagnostic process.

Got frustrated and walked away. May mess with it later today or set it on fire. Not sure yet.

I was thinking maybe you need to de-carbonize the engine especially with the top cylinders. Considering there was a problem with the fuel recirc before, I would not be surprised if there is a heavy buildup of carbon on the top two cylinders. I use straight seafoam placed in a spray bottle and then spray it directly into the cylinder mouth. To do this I remove the carb cover. Start with a little spray while revving the engine using the tie bar (not the timing tower) but limit rpm to about 3500~4000 in short burst while spraying seafoam. When you start seeing black soots out the exhaust then increase amount of seafoam sprayed but not too much it will kill the engine. this shouldn't last but 2~3 minutes.