My wonderful Force (updated with pic)and new issues

[captquest]

I am lucky enough to own one of those wonderful force engines. Mine is a 1998, 120 horsepower. I have a little mechanical experience and don't mind working on my own stuff (good thing). I have had this motor (and boat) for two years and this is some of what I have done so far in that time.
Replaced starter (twice, they fried while trying to start with fuel problem))
Replaced flywheel, stator, and trigger (flywheel broke and damaged other parts)
" fuel pump, all fuel lines and added water filter
" impeller
" lower unit seal
" trim relay switches
I have rebuilt the carbs and cleaned out the fuel system
Over all though I have been out on the Bay and Gulf beaches dozens of times with no problems. I have logged many hours on this engine (and boat) and have only broke down two times in the water. Last night I popped the cylinder head to clean the carbon deposits and replace gasket. I noticed the bottom cylinder was a bit gunkier than the the others. After a little research (Iboats is great) I learned that my exhaust plate gasket may be leaking, and it's supposed to be a real pain to replace (from what I read). So here I go again.
Well I guess I posted this to attract other wonderful Force owners that would like to share their experiences. And if any one knows about the exhaust plate gasket issue, I would appreciate any info.
BTW my Key Largo boat is really wonderful, I wish (some times) I had a Yammy on it
May the Force be with you.

Well I'm getting other opinions on that exhaust gasket now so I'm a bit confused about it. I'm hearing every thing from weak spark to Ethanol damage? Any help would be appreciated.

 

[captquest]

Re: My wonderful Force

Re: My wonderful Force

How 'bout some expert opinions. what is causing this?
This a four cylinder with two carbs.

 

[Firemedic09]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

i am having a fuel delivery problem and it seems as though you have already been there. i have a 1986 force 125. what did you end up replacing and what carb kit did you use and where did you get it? im assuming you have dual carbs.

 

[Firemedic09]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

the brownish color looks like maybe that is a lack of lubrication. although you would expect maybe the top one to look llike that not the bottom as its the first to get what it needs from the fuel supply. i will look into it a little more as i am no professional with boats. more of an automotive, fire and EMS guy myself. hope maybe it helps a little. if i find out more i will get back to you.

 

[captquest]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

Thanks Firemedic,
Yea, some one an another site suggested I had a fuel delivery problem. This is a duel carb setup, but my understanding is that both carbs feed all four cylinders. I'm wondering if there is a valve or reed valve for that particular intake port that may be sticking? One local mechanic believes a weak spark in that cylinder may cause the build up of deposits. Another post I read points at the exhaust plate gasket. If that gasket blows then water tends to get in the bottom cylinder and fowls the plug. I'm not sure this looks like water. As for lubrication, I routinely "read" my plugs after running the engine. All the plugs will have oil on them, that one gets blacker and gunkier. The cylinder walls look smooth and normal, no signs of heating or seizing it looks like the others.
The carb kit I used was nothing more than new needle valves and a gasket set, I bought it from a local dealer. I have seen carb kits on this site. The most important thing is to soak the whole carb overnight in a good solvent. Look in the Boat Repair FAQ's section of this site.

 

[steelespike]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

Perhaps just a slightly leaky head gasket,the block surfaces sure look rougher than the other cylinders.How did the plugs look?

 

[pnwboat]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

Looks like something is going on with the bottom cylinder. Difficult to say what exactly though. Obviously it is burning differently than the other three. I would suspect a water leak or compression problem.

Have you ever done a compression test before you pulled the head? I'd continue with cleaning up the carbon deposits, put a new head gasket on and perform a compression test on all four cylinders. That'll tell you how well the rings are sealing. Readings should be in the 120 LBS + range and within 10% from lowest to highest reading. If the bottom cylinder shows low compression, then you may have a bad/broken ring, or the sealing surface between the block and head is not true and is preventing the gasket from sealing.

The exhaust plate gaskets (there are two) are not that difficult to replace. It's a little tight around the bottom of the plate because of the proximity to the lower cowling if you're trying to scrape off the old gasket and maneuver around in that general area with wrenches etc. The gaskets are not that expensive and it may be a good idea to do them just in case.

Reed valves are easy to check but you have to remove the intake assY. which means you will probably need new gaskets. Afterwards you may have to link and sync the carbs because when you take the intake off, it will disturb the positioning of the carbs in relation to each other. There is a seperate intake for each carb. If you have a bad reed valve, the motor won't
run very good, especially at idle.

 

[maxum247]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

Sounds like it could be a spark problem on the bottom cylinder.
It doesn't look like the cylinder is firing correctly.
If it were water leaking into the cylinder at the head gasket the sparkplug for that cylinder would be clean as a whistle and maybe the piston too!

 

[captquest]

Re: My wonderful Force (updated reed valves)

Re: My wonderful Force (updated reed valves)

Well I finally took it to a mechanic to have a good look at it. So far, he found two broken reed valves. Our concern now is if the pieces that broke off did any damage to the engine (the reed valves are metal). As I said before, the cylinders all look OK. But there is that one cylinder that seems to have a bit less compression than the others.And the one that is gunkier. Has any one ever have a broken reed valve damage their engine?
BTW, the carburetors were "spitting" fuel back when the engine was running or trying to run. That's a good sign that reed valves are bad.
My mechanic will put it back together and continue to examine the engine and performance. I'm hoping for the best at this point.

 

[RRitt]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

it is a bloody shame that mercury wasn't required to change the name of the engine when they bought out Force. Now all the people who have Chrysler-Force-USMarine engines end up getting all the disrespect due to the really crummy engines that Merucry built ... you know the ones with such brilliant ideas like self-destructing stators and plastic reed valves. I will never, ever buy a Mercury engine. What they did to Force and Force owners has proven beyond all doubt that they are a company without honor.

 

[tysonnathan]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

it is a bloody shame that mercury wasn't required to change the name of the engine when they bought out Force. Now all the people who have Chrysler-Force-USMarine engines end up getting all the disrespect due to the really crummy engines that Merucry built ... you know the ones with such brilliant ideas like self-destructing stators and plastic reed valves. I will never, ever buy a Mercury engine. What they did to Force and Force owners has proven beyond all doubt that they are a company without honor.

What year did Merc buy out Force?

 

[199675hpforce]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

I read that that all new outboards about the same none better or worse. I have 96 force by mercury with single carb to three cyl. Im not saying its a good engine but not a bad one either. i also have a miss and cant figure it out maybe a trigger?

 

[roscoe]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

1990 was the first model year to carry the Merc name.

I, unlike RRitt, like the Merc Forces better.
He apparently has had some bad experiences.

So have I, with the crappy ignition systems on the 70's Chryslers, and the mid 80's US Marine Forces.

Zero problems with my 1995 and later Merc Force motors.

 

[captquest]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

Yea, that's a real twist. I have always heard that Mercury actually improved them over Chrysler and USMarine. By the looks of these forums, Force are not the only outboards to break down.

 

[Proline_19]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

Replying to "CaptQuest"... I'm having some of the same issues that you've expressed here. My '95 Force 120 is spitting fuel from the lower carb at lower rpm. Also, in the lower two cylinders, both plugs are unusually clean. So, the fuel spitting from the carb is a "reed valve" problem. I know nothing about the reed valves so if you have any info I'd appreciate it. Also, could you offer any info on the "clean plugs" in cylinders 3/4....? Thanks!

 

[captquest]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

OK Proline (nice boats BTW),
This is what I understand about that. If there is a slight back pressure spitting back at you from the carb, and if you are seeing a build up of moisture (fuel) on the spark plugs, and if your engine generally runs and idles poorly, then I would bet on reed valves. Replacing them is not to difficult, it requires to remove the carburetors and intake manifold. You would need a gasket for the manifold along with the reed valves you are replacing. You would most likely have to look first to see how many (reed valves) you need. Of course I would check for other possible problems before drawing conclusions. Make sure your carburetor floats are not sticking and causing overflow, or that the gaskets are not leaking. Check compression and spark. There are a couple of good threads in here about reed valves

http://forums.iboats.com/search.php?searchid=1738284

 

[Proline_19]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

Hey, thanks for the reply. I'll check the compression this weekend as well as the reed valves. Yeah, Prolines are nice boats.... I just wish I had a good running motor to push it.... I definately agree with your statement about that Yamaha...

 

[199675hpforce]

Maybe mine has bad reed valves?

Maybe mine has bad reed valves?

How many on 75hp three cyl, i can remove the carb easy enough. Does the intake just unbolt and pull straight off. How much are reed valves

 

[RRitt]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

1990 was the first model year to carry the Merc name.

I, unlike RRitt, like the Merc Forces better.
He apparently has had some bad experiences.

So have I, with the crappy ignition systems on the 70's Chryslers, and the mid 80's US Marine Forces.

Zero problems with my 1995 and later Merc Force motors.

If you look at service records the mercury forces have much higher incidence of blown power heads at lower hours. This is because the force engines cold sneeze and some brilliant Mercury engineer thought it would be a bright idea to squeeze out a few extra horsepower by using composit reed valves. Well, guess what? Composites crack under cold sneezing and cracked reed valves run lean ... and lean 2 stroke engines run hot and don't get enough oil ... which leads to blown powerheads. There was a service bulletin if you care to look it up.

I don't think I need to spend a lot of time describing the stator problems. Everyone who works on outboards should already be familiar with mercury's ill fated efforts to develop universal stators in the early 90's. I don't know the exact details of why the failures occur but i would guess its because they used cheap glue. That would be brunswick's style.

So ... why do I like Chrysler's better? Because they don't self destruct. You take care of them and they take care of you. You spend $50 per year maintaining your chrysler and it will run like a clock and last forever.

Mercury Force? You can maintain them perfectly and they still self destruct in a big way. And why? so that brunswick could cut some corners and squeeze out a few extra dollars of profit.

another great example is Mercury's choice of hydraulic fluid. They used ATF because it was cheaper than ND30 or ISO32. Never mind that it cut 5 years off life of trim system. Not their problem. Warranty was over by then either way. They saved at least 0.05 to 0.10 per engine by using ATF.

 

[captquest]

Re: My wonderful Force (updated with pic)

Re: My wonderful Force (updated with pic)

Well I'm not one to argue with you RRitt. I do not claim to be an expert on boat engines. I can say that I have owned both a Chrysler and the Merc Force engines. In the late 1980's I bought a 16' Manatee boat with a Chrysler 65 HP, I believe it was a 1981 or 82. It had a damaged cylinder due to a cross threaded spark plug. The engine was run after metal pieces from the threads got into the cylinder. I bought it and rebuilt the power head myself. I had that little boat for almost six years with very few problems (some of which were with ignition). So I can not speak to badly of the Chrysler. Now I am blessed with a wonderful fishing boat that is attached to Merc's version of the infamous Force. I can only say that it is over ten years old, and I'm sure several hundred hours. As I stated before I have put many trips and many hours on it myself in the last two years. And It may very well be self- destructing. After the "reed valve" job, it seems to be running just fine. It idles and has it's normal power back. However, my mechanic and I both noticed that it is a some what noisy engine. And we are only guessing now if some thing new is about to happen. It was thoroughly checked and vital signs seem normal. I'll keep you posted.
BTW the reed valves in my motor are made of steel .