90hp force NEED HELP with model year

[cobia-boat]

I just got a 90hp force motor that needs a impeller and I don't know what year it is. The tag is completely worn off. Im guessing its a 1990 its black, and the cowl cover has a couple of red stripes around the bottom. The only thing that confuses me is the the outside is all black and the motor is all white??

 

[RRitt]

Re: 90hp force NEED HELP with model year

are you sure that it is a 90hp Force?<br />white is the chrysler color. Maybe somebody dropped a used chrysler powerhead onto a late model force. In which case ... why did it blow up? Did it blow up becuase of the reed valves? If so, then does it still have mercury reed valves in it? If it has mercury reeds then does it also have the self-destructing mercury stator?<br /><br />check the side of your stern bracket. there might be a motor plate there.<br /><br />also check this website and find the gear housing that looks like yours. look for location of water inlets, shape of skeg, and whether or not you have a nosecone on your prop. <br /><br /> http://www.mercruiserparts.com/SelectModelType3.asp?class_id=2

 

[cobia-boat]

Re: 90hp force NEED HELP with model year

I have picures but cant seem to get them on here.<br />It looks totally stock and like a force from the outside. Would there be any markings on the motor and could you put a chrysler powerhead on a force??

 

[RRitt]

Re: 90hp force NEED HELP with model year

force is chrysler. The core engine is the same whether built by chrysler, us marine, or mercury.<br />stuff like crankshafts, blocks, pistons, manifolds, flywheels, starters, cylinder heads, etc<br /><br />but the support components from mercury are poop.<br />in 1991 mercury put in their own reed valves. The valves fail and cause the powerhead to blow. <br />they also replaced the stator with a universal mercury unit. Both merucry and force engines have the self-destructing stator. I don't know what years are affected by stator. The reeds affect every engine of 70hp and larger manufactured after mid-1991.

 

[roscoe]

Re: 90hp force NEED HELP with model year

cobia- email your photos to me.<br />I wil post them for you.<br />roscoe33@mac.com<br /><br />Need photos of:<br />lower unit, side view.<br />starboard side of powerhead with the cowl off (ignition).<br />eye level view of the tilt and trim.

 

[RRitt]

Re: 90hp force NEED HELP with model year

i did some checking and cross-referencing. <br />It appears that mercury changed the ignition twice after aquiring Force from US-Marine. I can not find any changes made by US Marine from Chrysler other than increasing the impeller size and splitting the gearshaft in 1989/1990.<br /><br />The first change was made by mercury in mid-1991. They replaced the stator, CDI modules, and coils. So if your engine has the black or blue CDI modules then you are definitely good. It appears that mercury stuck with this system thru 1995.<br /><br />In 1995 they changed the ignition again. This time they went away from the switchbox and back towards a CDI approach. From the drawings it apears that they split the CDI function between the trigger and the coils. These engines appear to have CDM modules with integrated coils.<br /><br />I do not know which of the two is the self-destructing system. However, I would guess that is the 1991-1995 version. But - then again it seems like the mercury engineers design their engines to fall apart after ten years so it may be too early to tell on the post 1995 design.

 

[roscoe]

Re: 90hp force NEED HELP with model year

Sorry to contradict RRitt, but the ignition systems changed several times, simetimes within the model year, different years for different size motors. They have used atleast 8 different ignition systems since 1984, along with 3 or more generating systems.<br />USMarine used 4 different ignitions from 1984-89, battery breaker, magneto breaker, prestolite, and BIM.<br /><br />Triggers were being used on some models in 1984, on most by 1987.<br />The trigger has one function. It sends a reference signal to the ignition system, telling it the position of the flywheel. <br /><br />Yes there was a stator problem with the old black Merc stators, but they replaced them with red ones.<br /><br />And you can keep any motor with the blue cd units.<br />I'm not ever working on one of those again. Any glitch in the system, and the cd was prone to failure. Intermittant failures were common, and very difficult to pinpoint.

 

[RRitt]

Re: 90hp force NEED HELP with model year

roscoe, thanks for your input. I was trying to figure out which year model engines have the bad stators. based on what yoiu said it is the 1991 to 1995 stators that are failure prone.<br /><br />It isn't so much the cost of the stator as the labor that is often required to remove the flywheel. brand new stators are only $125. It's the cost of labor that kills you. Regarding the blue CDI. Why bother trying to pinpoint a problem? You can get entire working black CDI/Coil plates for under $100 off Ebay. same trigger for both. just replace the whole darned thing.

 

[roscoe]

Re: 90hp force NEED HELP with model year

Try telling a customer that you are going to replace their ignition system with used items off ebay.<br />And that you aren't gonna warranty the parts or labor.<br />Or that you are gonna replace the entire system because you can't figure out which part is bad.<br />You also can't mix n match parts from the different systems.<br /><br />Either way, you won't be in business long.<br /><br />People want their stuff fixed right, the first time, with warranty.<br />They get real mad when they have to pay SeaTow charges and have their weeks vacation ruined.

 

[RRitt]

Re: 90hp force NEED HELP with model year

well, first, i'd quickly scope out what's being dumped on ebay and figure on doubling the price. if there was multiple units on ebay then I'd tell them just what you said earlier.<br /><br />"Any glitch in the system, and the cd was prone to failure. Intermittant failures were common, and very difficult to pinpoint."<br /><br />I'd say that I can fix their system with new parts and give them the standard warranty for $xxx. However, to fix the system so that it won't break even after the warranty expires then they'll need to convert. I can do a full conversion with new parts for $yyy. A more budget minded alternative would be to get used parts from ebay and replace the entire system with a working, but no warranty system for $zzz.<br />With mercury sucking out so much profit, I could make more money in fewer hours while delivering a better end product to the customer for $zzz. Not surprisingly customer $zzz will be a loyal customer who thinks his mechanic walks on water.<br /><br />you just hafta be sure that you fix it right. Which shouldn't really be a big deal for a guy like you.

 

[roscoe]

Re: 90hp force NEED HELP with model year

If you want to buy used electronics, go ahead, but there's a reason why they are being sold.<br /><br />If you don't want to buy from Mercury, then buy aftermarket.<br /><br />Oh, the customer wants it tomorrow. He doesn't want to wait for you to hunt up some used parts and wait for delivery, Then find out that the module doesn't spec out, and end up waiting for 3 more weeks for you to find another one. By now I've got 3 hours labor tied up in ebay and a bad part sitting here that I'll have to eat.<br /><br />If you're a backyard do it yourselfer, fine. But if you need to get something fixed, and have 27 boats in line to be fixed, and you're charging $80+ an hour, you better not mess with used parts.

 

[RRitt]

Re: 90hp force NEED HELP with model year

dude - I've done the professional mechanic thing from tune-ups to race cars to frame-up restorations. It doesn't work on me. <br /><br />Spotting the good used from the bad used part is not difficult. Knowing which parts break on their own and which parts break because something else dragged them down isn't that difficult either. Of course you don't buy used parts when they are the source code for breakdowns. It's your job as a mechanic to know the expected lifespan of components.<br /><br />Yeah, if you want to fix the maximum number of boats/cars per day and don't care what it costs the customer then dealer parts with dealer diagrams with dealer wharehouses are the way to go. But that was never my bag. I selected what I wanted to work on and turned the rest down. The hourly profit was greater, the stress was lower, and the satisfaction of being a craftsman instead of a grease monkey meant a lot to me.<br /><br />so, in the end, not all mechanics like having 27 boats in line and not all customers want their boat to be one of 27 waiting in line. To each his own. There's more than one way to do things.

 

[roscoe]

Re: 90hp force NEED HELP with model year

Back to the topic of this post.<br />Here are the pictures of the motor in question.<br /><br />

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<br /><br />Lower unit appears to be 1990-91-92A<br />Ignition is Prestolite (blue cd modules and coils) which was used on the 90-91c model 90hp.<br /><br />So I would say your guess of 1990 or 1991 is correct.<br /><br />There are a few things on the powerhead, besides the white paint, that don't quite look right. I suspect the powerhead may have been exchanged with an 85 hp powerhead. Really hard to tell for sure, not much difference to the powerhead itself over the years. The flywheel looks like the older style.<br /><br />Complete waterpump kit from Mercury should be part number fk1204-1.<br />Just the impeller is 47-803631T<br />Aftermarket impeller part number would be 18-3017

 

[roscoe]

Re: 90hp force NEED HELP with model year

cobia, I have to ask, What are all those black hoses/cables behind the head?<br /><br />Are they all hooked up to something or just lying there?

 

[cobia-boat]

Re: 90hp force NEED HELP with model year

The cables are just lying there, I just put the motor on the boat, and havent wired it up yet I put them under the cowl to keep them dry. <br /><br />thanks so much for your input guys, the only other questions I have are the carburators dont have the plastic filter covers, can I get those somewhere. And under the blue coils there a couple of black hoses with screws pushed into the ends, is that normal or should those be hooked up to something???? <br /> I see you guys talked about bad coils and ingitions, does the one on it look to be the good one. I paid 200 buck from a friend for the motor and dont mind investinmg a few bucks into msking it reliable. I do know it needs the water pump and I did start it real quick before I put it on this boat.

 

[RRitt]

Re: 90hp force NEED HELP with model year

cobia-boat,<br /><br />your air filter cover is a single piece metal affair that is held on with six bolt (two bolts into each carberator). It is more of a duct than a filter since it just sucks air in and doesn't have any type of foam or paper filter. However, on the bottom it does have a hose connection for recirculation.<br /><br />that thing under your blue coils is the fuel pump. one of the hoses is gas in from tank and the other is gas out to the bottom carberator. If you are going through the engine trying to dot the i's and cross the tees, then you might want to spring for a fuel pump kit. They are here on i-boats for under $10.<br /><br />regarding issues like coils, reeds, and stators. <br />your flywheel is white and your intake manifold is white. Chances are that you have the chrysler engineered reeds and stators instead of the mercury versions. Which means that there is no reason to worry about either of them. Somebody probably got took a 90hp with blown powerhead and spliced it together with an 85HP with seized gearcase. You got the best of both.<br /><br />There is a much more active market for blue coils on ebay than black. blue coils get more bidders and black coils don't get very many at all. Which means that not many people need to replace broken black CDI/coil assemblies and they will sell for less due to decreased demand. <br /><br />Whether or not to replace is a personal decision. Around here, breaking down while hunting cobia isn't so bad. One breakdown every ten years isn't really that big a risk since cobia hang close to shore. But grouper digging is a different story. any risk of breakdown in a single engine rig is the risk of getting killed. <br />The other caveat is using supply & demand to your benefit. since the blue break more often than the black there is a higher demand for them. In the world of ebay demand equals price. You couldn't sell gold bars for 50cents if there wasn't demand. A lot of old force parts never break and there's little or no demand for replacements. Specifically, you might be able to sell your used blue coils for more than the cost of used black ones. But that doesn't eliminate the labor. It takes about 1 hour to swap out the cdi/coil plates. just be careful not to pull out any wires, break off any terminals, or break the rubber mounting studs. there should be a sticker between thermostat and flywheel with wiring information and color codes for black cdi.

 

[RRitt]

Re: 90hp force NEED HELP with model year

and yup, roscoe, that means that if I were still doing mechanic work that I would charge the customer about $250 ($100 labor, $150 parts) to do the swap verus 2-3 hours labor to isolate and replace a single bad cdi module ($200 labor plus $150 for new cdi). Customer would pay less for a better fix and I would net close to $200 per hour. I never issued credits for cores. I consider it part of the price for knowledge. My last stint as a mechanic was doing restorations on the old aluminum body mercedes sportscars. it's a very lucrative approach that doesn't require employees. Being the lazy type who never wanted to work more than 2-3 days a week, no employees was a great thing.