1990 150hp Force - no forward gear

[w_huisman]

First of all, I'm new to outboard motor repair, so please assume I know zilch in your replies. However, I am quite mechanically inclined and I expect I'll catch on pretty quickly.<br /><br />With that being said, I was out in my boat this weekend fishing. After fishing one spot for an hour or so, we decided to move. I started the motor and threw it into forward. There was an audible cluck and then no more forward gear. Reverse still works fine.<br /><br />The throttle cables appeared to be working fine, so I knew that wasn't the problem. And actually, that's all I knew to check at the time. I was at a loss. But once I got home I fired the motor up again, and using a needle nose pliars to manipulate the linkages on the motor just a little further than the throttle cables, I was able to get forward to engage.<br /><br />Judging from the little bit of info I've gathered so far, I'm guessing that some sort of gears are shot in the lower unit. <br /><br />What do you all think? Can these gears be replaced? If they can, where can I buy the replacement gears? I really don't want to spend $1000+ for an entire new lower unit for my $3000 boat, if I can avoid it.<br /><br />Thank-you in advance!

 

[graddy]

Re: 1990 150hp Force - no forward gear

Drain the gear lube, if you get metal chunks comeing out with the oil, you need to have a new gear set installed. Call your local Mercury dealer for parts info.

 

[w_huisman]

Re: 1990 150hp Force - no forward gear

Draining the gear lube sounds simple enough. Once I drain it and probably find the metal shavings/chunks I'm expecting, how do I proceed? (besides calling the local dealer and ordering parts)?

 

[w_huisman]

Re: 1990 150hp Force - no forward gear

I started draining the gear lube now. What color is that stuff supposed to be??? It looks milky white with speckles in it. I'm guessing the specs are metal, but I've never seen milky white gear oil before.

 

[Yepblaze]

Re: 1990 150hp Force - no forward gear

Milky white indicates water intrusion. That might indicate the lower unit is in need of seals and any possable repairs from damage from the water in there.<br /><br />That much being said, does not guarantee that the lower unit is at fault for the no go situation but it's a good place to start looking albeit not easy or cheap.

 

[w_huisman]

Re: 1990 150hp Force - no forward gear

Unless you guys talk me out of it, i'm gonna try and pull the lower unit when I get home. Of course, I don't know what seals you're referring to, but I'm gonna find out.<br /><br />Any advice?

 

[w_huisman]

Re: 1990 150hp Force - no forward gear

Alright guys. I got the lower unit removed tonight. All it took was 6 bolts and a pin.<br /><br />Please check out the pics here in the Boat album.<br /><br /> http://community.webshots.com/user/wadinator-date <br /><br />I'm not sure where to go next, but I'm guessing there's shredded gears at the bottom of that lower unit. Are there gears down there, parallel to the prop?<br /><br />BTW: When I drained the milky gear oil out of there, I never did see any larger sized metal chunks. Please lemme know what you think. Thank-you!<br /><br />Wade<br />(beginner)

 

[w_huisman]

Re: 1990 150hp Force - no forward gear

BTW: When you go to the boat album at the above link, please open one of the pics showing the boat and the suburban. Then click on the blue circle with the arrow pointing to the right to start seeing the pics of the motor taken apart.<br /><br />Let me know if you had troubles seeing them and I'll try and do something else, ok? Thank-you!<br /><br />wade

 

[scubarobby]

Re: 1990 150hp Force - no forward gear

pictures looked good. I am no expert but I thought I might make a few comments. Be sure that you have a probablem before you take your lower unit apart for nothing. You obviousely do have at least one seal leaking. I would check behind the prop for fishing line in case it got wound under your seal.<br /> It is not a good signe for there to be matalic specs in your oil but it is also not necesarily fatal. I literally took a hand full of chunks out of mine two seasons ago and it is still going. <br /> I am surprised you didnt have some larger peices on the magnet or do you have a magnet on your lower drain screw.<br /> I would replace the shifter shaft seal and the seal under your water pump while it is off. They are pretty straight forward.<br /> You can also use a bicycle pump to check the seals. They shuould hold between 10 and 15 pounds.<br />You did say I beleive that you were able to get it in gear manualy so I would play with the shifter linkage adjustment some more. Robby

 

[w_huisman]

Re: 1990 150hp Force - no forward gear

"pictures looked good. I am no expert but I thought I might make a few comments. Be sure that you have a probablem before you take your lower unit apart for nothing."<br /><br />-----What else could the problem be? My boat used to go forward when I put it in forward, but after this big klunk sound happened on saturday there's no more forward drive. and the grease in the lower end looks more like creame of mushroom soup!<br /><br />"You obviousely do have at least one seal leaking."<br /><br />-----Which one is that? So far I've only found one gasket, and it really didn't look like it was in that bad of shape.<br /><br />"I would check behind the prop for fishing line in case it got wound under your seal."<br /><br />-----Good idea! I'll check it out.<br /><br />"It is not a good signe for there to be matalic specs in your oil but it is also not necesarily fatal. I literally took a hand full of chunks out of mine two seasons ago and it is still going. <br />I am surprised you didnt have some larger peices on the magnet or do you have a magnet on your lower drain screw."<br /><br />-----I don't know if that bottom oil plug is a magnet or not. I'll have to check that out too.<br /><br />"I would replace the shifter shaft seal..."<br /><br />-----Which one is that?<br /><br />"...and the seal under your water pump while it is off."<br /><br />-----What's the water pump?<br /><br />"They are pretty straight forward.<br />You can also use a bicycle pump to check the seals. They shuould hold between 10 and 15 pounds.<br />You did say I beleive that you were able to get it in gear manualy..."<br /><br />-----That was on dry land, not on the water with a "load" on the prop.<br /><br />"...so I would play with the shifter linkage adjustment some more."<br /><br />-----I haven't touched the shifter linkage adjustments yet. I'll have to look for those.<br /><br />-----Thanks Robby! You said I've obviously got one seal leaking. How do I tell which one? Plus that black plastic piece is cracked around one of it's mounted screw holes (if I remember right, the nuts that hold this piece on are supposed to be tightened to 40-50 in-lbs - that's what it says on the part).<br /><br />-----Does anyone know of a diagram online somewhere that has the parts of the motor labeled, so I can learn what these parts are called?

 

[scubarobby]

Re: 1990 150hp Force - no forward gear

Wade<br />I think the part that you said is cracked is the water pump housing. Inside is a rubber impeller. <br /> I dont know the particulars of your motor as I am not a merc mechanic but since none are jumping in at the moment I will try to help. <br /> The first thing you will need is a manual. If you have a local library that is a good place to start. <br /> I think I was getting the cart before the horse in my last post. If it were me before I start fixing seals I would want to know if the lower unit works. <br /> I would suggest a slower approach. when you thought it was in gear out of the water, that would have been a good time to try it in the water under load.<br /> You may be able to figure a way to test it out of the water by holding the prop while you turn the shaft. <br /> I guess what I am trying to get at is that there is no sense in fixing the seals to a bad lower unit. The milky oil and specks in your oil dont necesarily mean the lower unit is bad. All that tells you is that you have a seal problem.<br /> Play with it as is or consider puting it back on the motor to test in the water before getting into the seals.<br /> Or if you are already convinced that the gears are out then the manual and the board may help you take the lower unit apart but I do caution It is not a simple operation. I would be glad to help in any way I can but I as I said before I am not an expert with mercs either. <br />Robby

 

[w_huisman]

Re: 1990 150hp Force - no forward gear

Heck, it's no problem to throw that lower unit back on the boat, and I could easily get a big tupperware tub out of the basement and run that motor in my driveway.<br /><br />But if I do that, I need to put some gear lube back in the lower end. Is there some lube I could use temporarily while I do these driveway tests, that I could pick up from an auto parts store or something? Like some 80W or 90W gear lube or something?

 

[roscoe]

Re: 1990 150hp Force - no forward gear

Hi Wade, be patient, there are experts on this board that will be along with help, they may not be here now because they have jobs.<br /><br />OK, definitely get a manual. Click the link at the bottom left of this page to buy one here from iboats. $28. You need it for part id, what to grease and what NOT to grease, torque specs etc.<br /><br />Metal in the gear oil is not fatal. Neither is the water.<br /><br />The driveshaft spins continuously when your engine is running, along with the gears in the lower unit. There is a shift rod that connects the shift cable up top, and the clutch dog in the lower unit (l/u). The clutch dog is on the prop shaft with a cog on it, it slides fore and aft. It is either in gear or out of gear. It slides one way for forward, the other way for reverse, with a midpoint in between for neutral.<br /><br />So you have 2 separate problems right now. <br />1--water intrusion in the l/u.<br />2--clutch problem.<br /><br />I would reinstall the lower unit and fill with new oil. REPLACE the fill and drain screw seal wahsers. This may be the source of the water leak.<br /><br />You also have seals around the prop shaft, around the driveshaft, and around the shift shaft.<br /><br />One of the pictures you posted is labeled "the thing the driveshaft goes thru on top of the l/u". This is your waterpump. There is a rubber impeller inside that needs to be replaced, or risk an overheat.<br /><br />After reinstall of l/u, adjust the shiftshaft linkage. Hard to do without the manual, there is a whole page of directions on this alone.<br /><br />Then take it for a test run and see if you get more water in the l/u oil.<br /><br />This may be all you have to do to fix your problems.<br /><br />DO NOT under any circumstances remove the small screw near the front of the lower unit about inline with the prop shaft!!!!!!!!!<br /><br />Only remove the drain/fill screw way at the bottom of the gearcase, and the vent screw up at the top of the l/u.<br /><br />Good luck, I hope this helps.

 

[roscoe]

Re: 1990 150hp Force - no forward gear

An auto parts store will have gear lube for your motor.<br /><br />While you are there, pick up a couple cans of SEAFOAM fuel additive to add to the gas. Also a couple spray cans of engine DECARB to decarbonize the inside of the cylinders and rings. This is very imprtant to do to maintain your FORCE as they are old technology (from the early 70's) and run very dirty. You need to keep the rings free moving or say goodbye to the motor.<br /><br />The SEAFOAM is for maintenance, the spray cans are for carbon removal.<br /><br />Buy at least 2 cans of decarb. Some people use one can per cylinder.<br /><br />Decarb process:<br /><br />Run engine at fast idle, with engine running<br />spray liberal amount into each carb,<br />spray some more, spray a larger amount into carbs until engine chokes out and stops,<br />remove spark plugs and spray decarb into each cylinder, install the spark plugs, let it soak for 1 to 12 hours. <br />Start the engine and run at medium throttle, or if at the lake, run it at full throttle. It won't hurt to spray some more through the carbs. Run it for atleast 10 minutes to flush the crud out of your engine.<br /><br />About the rubbermade tub: It won't be big enough!! I use a 100 gallon water tank and it just barely is big enough. Once you put it into gear, even at idle, you will not have any water left. You are not really supposed to put into gear without a load on the motor anyway, but I do it and keep it at idle only. My water tank still looses 1/3 of the water.

 

[w_huisman]

Re: 1990 150hp Force - no forward gear

Thank you so much for that thorough response Roscoe!<br /><br />So which manual do I buy? The top one on this page or the bottom one?<br /> http://www.iboats.com/boatproducts/mallsearch/force_manual/ <br />I'm thinking the shop manual (first one) would be more helpful than the tuneup/repair manual (3rd one). The tuneup/repair manual says it's only for 1-4 cylinder engines anyways, and mine is a 5 cylinder.<br /><br />Is the gear oil really just plain old 80w or 90w gear oil you can buy at a car store?<br /><br />Why do you suggest replacing the impeller on my water pump? What's wrong with the one I have? Do I get a new water pump housing (the cracked black plastic thing that the shaft goes thru) with the new impeller?<br /><br />Are you thinking that adjusting the shift shaft linkage may fix my problem?<br /><br />Here's what I'm thinking. My #1 goal here is to get this boat to go forward again. In the process I will replace the gear oil in the l/u. Water intrusion in the gear oil is not my main concern. So for now I will only buy a repair manual and put the lower unit back together and reinstall it (replacing the water pump if you tell me why you believe I need to) on the bottom of the motor. Then pump it full of gear oil and do the shift shaft adjustment as per the instructions in the manual. If that fixes the no-forward problem, AWESOME! Then I will keep a close eye on the gear oil, looking for water intrusion, and then begin to fix possible things where the water could be intruding from.<br /><br />I gotta head to lunch for a while. I'll review these posts when I get back and see if I missed something.<br /><br />Once again, thanks a TON Roscoe!

 

[SlowlySinking]

Re: 1990 150hp Force - no forward gear

Wadinator, interesting question and loads of replies, one question, you mentioned that by manipulating the shift linkage you were able to get it into both forward and reverse gear. The Force manual indicates that the gears are in constant mesh, only the shift clutch moves, is there a chance that your problem is simply an adjustment of the shift cables?? Sounds too easy but,,,,,,,,,,

 

[roscoe]

Re: 1990 150hp Force - no forward gear

I have the Clymers manual, have not seen the Seloc so can't comment on that.<br /><br />The drain/fill screw washers are only about 50 cents so replacing them may save you from having to drain and fill at a later date.<br /><br />Auto parts store should have marine products, 2 cycle oil, decarb, gearcase oil, marine grease, etc. If it is a NAPA store, they may even have your impeller. I live in a town of 5000, and even 2 of the gas stations have lower unit gear oil.<br /><br />The waterpump housing and gaskets DO NOT come with the impeller. The impellers are rubber and dry, harden, crack, and break over time. They also fail in a few seconds if the motor is run out of the water. Many guys here change the impeller ever other year. If the impeller fails, you will overheat the engine. This is very damaging, especially for some FORCE models, and can cause severe damage including ring-piston-cylinder restruction, as well as exhaust manifold warping.<br /><br />Use this link to order online from Mercury/Force.<br /><br />http://www.mercurypartsexpress.com/PartsExpress/ProductSelection/ServiceParts/sph ome.asp?CID=<br /><br />You need to enter in the motor serial number, the site will then only show you the parts for your motor. Exploded views and parts listings with prices.<br /><br />I would go ahead and get the impeller and the top gasket, and the housing cover that is cracked. Get it done and not have to pull it apart again.<br /><br />I'm off to work now, keep us posted.

 

[w_huisman]

Re: 1990 150hp Force - no forward gear

Roscoe, you're not gonna believe this....<br /><br />I found the tag on the motor that's supposed to have the motor serial number on it, and the numbers are worn off!<br /><br />I pulled the cover off the motor to look around in there. I wrote a few numbers down that were on the "block", but they're aren't right.<br /><br />Now what me do?

 

[w_huisman]

Re: 1990 150hp Force - no forward gear

BTW: I got the Clymer shop manual ordered and on the way!

 

[w_huisman]

Re: 1990 150hp Force - no forward gear

I've now got the Clymer repair manual and I'm getting ready to put the lower unit back together, but first I want to clean/flush the lower unit out, since all the gear lube was milkey colored.<br /><br />What can I use to do this?<br /><br />PS: Where else can I find the motor's serial #? It's worn off the tag on the motor.