Force 40 - alternative props?

[help_ma_boab]

I have been an avid reader of these forums for a little while now, (lots of good tips and info), and I get the impression that mid-range Force outboards are prone to ‘spun hubs’. Being a Force 40 owner myself, I have begun to think that I should maybe carry a spare prop. Anyways – I took the prop off to get the part no, only to find that not only is there a splined hub arrangement, the hub and prop shaft are both drilled thru, and there is a shear pin in there too. Is this normal? Will this give me less choice of alternative props? Outboard is a Force 40 (’95 I think) ser no OE002172. Prop has what looks like the no 48818335A40 stamped on aft end, and 12 ½ stamped between blades. To me it looks to be a ¾ “ shaft, and prop appears to be 10 ½ “ diameter. Anyone any ideas on what alternative props may fit? – the shear pin thing has confused the hell outta me – I do not see it mentioned on other prop specs!

 

[St. Johns River Rat]

Re: Force 40 - alternative props?

I have a 50 HP Force, 1990 year. Props for Forces don't look like other styles. Mercury dealers will cross-reference to their prop style and swear<br />up and down it will fit. And they don't. Look for an older marine dealer with years of experience, take your prop with you and let them see it to insure a proper match up. I had to have one specially made. Cost was no more, just that they had to dig the mold out of storage to create the pitch/size I wanted. Quicksilver/Mercury in the states can help you with that.<br />Hope this helps.

 

[help_ma_boab]

Re: Force 40 - alternative props?

Hi St Johns,<br />I have ordered a manual from amazon.com, but it will be a while getting here. Do all these Force motors have a splined shaft AND a shear pin? My owners guide doesnt mention a thing about it - doesnt even tell you what size prop is! Does your 50 have splines AND shear pin? Is it maybe only motors for UK market done this way? This post is starting to get a bit long -- so last question -- If all these Force motors have splines AND shear pins, it must surely make them almost immune to 'spun hubs' and the posts I have read just gotta be talking about different motors?<br />Anyways - it looks like its gonna be a whole lot easier to carry a coupla spare shear pins, rather than to carry a spare prop. What you reckon?

 

[ralphhotdog]

Re: Force 40 - alternative props?

Hi help_ma_boab; <br /> I just bought a 98 Force 40hp last month. I've been buisy working out some bugs(new impeller,decarboning,cleaning carb) but I haven't had the prop off yet. I'll try to pull it tomorrow to see if mine has a shear pin. I'll post again as soon as possible.<br /> HotDog

 

[ralphhotdog]

Re: Force 40 - alternative props?

Hi again; Today I pulled the prop off my 98 Force 40 hp. There was no shear pin just the splined shaft with a prop nut and lock washer. I also tried the prop from my 89 Mercury 35hp and it fit right on the Force.<br /> Something else I should mention, when I bought the manual for my Force I went to the Mercury parts express web site and ordered the manual for my Force and that is all it covers. Instead of having a manual that covers 1984-1999 4hp to 150hp. It's much simpler that way and has more information on my outboard.<br /> Good Luck<br /> HotDog

 

[roscoe]

Re: Force 40 - alternative props?

help_ma_boab , You have a 92 model year Force. Model number HO408E92F. The 95 and newer models use a Mercury lower unit. The 95 models started with ser number OE093700.<br /><br /> Yours still has the old USMarine/Chrysler lower unit. The manual refers to the pin as a "Drive Pin." It appears not to be a functioning shear pin. In fact, if the shaft and hub are splined, it would be impossible to break the pin, as all the splines would also have to break off.<br /><br />This set up does not prevent a spun prop hub. It is the outer prop housing that can spin separately from the hub. This is by design to prevent the entire impact from being transferred to the prop shaft, incase you hit a rock. A spun prop may leave you stranded some day, but it probably saved your lower unit from damage.

 

[help_ma_boab]

Re: Force 40 - alternative props?

Roscoe, Thanks for info - checked my owners manual again, and original receipt from dealer stuck inside back page - first purchased 1995 - ser no. OE002172. I wonder if some dealer had this motor on a shelf for a long while before he sold it? Or is it one of the very last ones with the non-merc LU? You reckon the hub could still spin without breaking the pin? I don't see how - the pin comes right thru the shaft and is flush with outside surfaces of prop hub. I think I may just have to be very careful not to hit anything, cos it sounds as if its not gonna give easily, and I could damage the prop.

 

[help_ma_boab]

Re: Force 40 - alternative props?

Hotdog, Thanks for the replies, between you and Roscoe, it looks like my motor has a pre-merc LU, while yours has the merc-style unit. Just makes it harder to source a spare prop. Marine leisure products here in the UK cost an arm and a leg, so I'll just need to keep asking people until I find someone who has actually fitted an aftermarket prop to my type motor before I invest in one. By the way, I really like my Force, and it performs well on a 4mtr RIB.

 

[ralphhotdog]

Re: Force 40 - alternative props?

Glad I could help. Good luck finding your prop. Maybe you could find something on E-bay. I hope I end up as pleased with my Force as you are with yours. It seems easy to work on and I think with some TLC and a few hard days on the water it will be running like a top.

 

[roscoe]

Re: Force 40 - alternative props?

By the looks of it, ebay will be a good source for you. Just be sure to email the seller before you bid, and inquire about shipping to your north Atlantic location.<br /><br />As far as the model year goes, I went to the Mercury parts website and entered the serial number you supplied. It came back with the model number I posted. The last two digits (92) are the year of production. It is entirely possible your motor sat in the crate for 2+ years. <br /><br />I just ran across 3 in crate 1997 Johnsons. They were at a dealership that just closed up. Now the owner has died and there was an auction.