Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacing.

khoonie

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Jun 22, 2005
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I lost everything from the prop nut back.... in the lake last week. I have a 1988 Force 125. Model # reads: "1254X8C". Serial # reads "2476". What prop hardware, in addition to the prop, do I need to fix this? I would like to go to a 15p - the lost one was 17p. Also, how do i determine if it is a thru-hub exhaust or not? Finally - how the heck could this have happened? What should I look for in the future to avoid loosing another one? Thanks in advance for any and all suggestions.
 
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BonairII

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Re: Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacin

iboats and/or other marine sites should have exploded parts diagrams of your motor(including the prop and hardware).

You probably lost your prop because a safety(probably a cotter pin) was missing.

The correct pitch prop will be impossible to figure out unless you have a working tachometer. If so, we need to know what your motor's optimal rpm range is(probably stamped on motor somewhere), what boat you have, how it's typically loaded....and what you want your prop to do(general cruising, pulling skiers, high speed runs etc etc).

My guess though...is that a 15P prop is way too low for your motor. I would guess that a 17-19P is probably more in the correct ballpark.
 
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jestor68

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Re: Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacin

1. google "1988 force parts"
2. select first vender on the list(marine engine)
3.select your 1988 125 from the list
4.select your serial number from the list
5.near the bottom of the parts list, see straight hub props, click on that
6.see the diagram of the 4 items that make up the prop parts.
7. order those 4 parts
8.go to Propco Propellors to get your new prop. They still make them.
 
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khoonie

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Re: Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacin

I have done that, however, when I put my serial # into the box, it rejects it and says "no such number found" or something to that effect. There are basically only two choices for the hardware,however. And it seems to be based on either a "flared or non-flared hub" or whether it is a "single or dual exhaust". I know I should be able to look at it and tell, but I do not know what to look for. If it recognized my serial #, that would have been determined by the input, I suppose. I will double check the serial number, but it was very clearly written on the sticker on the side of the motor... Thanks for your help.

Here is the input box:
Manufacturer: Mercury Marine Mercury Parts
Catalog: Force Outboard Parts
Year: 125 H.P. (1988) (View All)
Model: 1254X8C (View All)
Serial Number:
 

khoonie

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Jun 22, 2005
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Re: Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacin

The ideal rpm is 5000 according to the sticker, with the range being 4500 - 5500. I usually have two or three adults and quite a bit of fishing gear, a small 5 hp 4-stroke nissan and a three gallon gas can with it. I am generally pretty heavy - don't know the exact weights, though. Very rarely, the boat is used to pull a skier - but it needs a tune up if we are going to pull a skier - the engine needs work. One other thing - I don't think this prop uses a cotter pin - I am not sure how it slips if you hit something...
 
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Frank Acampora

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Re: Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacin

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Buy whatever prop fits and you like. It does not matter whether or not the prop is closed hub or Flared hub--thru-hub exhaust. Performance will be the same. You can use any prop listed for a 1979-1984 Chrysler 75-140 or Force 85-150 up until about 1991.

Your engine has a single exhaust exiting through the exhaust snout. They did not change to dual exhaust until 1989. If the lower unit has been replaced, and if there are six vertical water inlets on the leg running up to the anti-ventilation plate, THEN it is dual exhaust and should use thru-hub exhaust props. Note in my photos, the four water inlets right behind the prop, on the gearcase bullet. This is single exhaust.

If the prop shaft is still there, then you need a thrust washer, prop, spacer or Flare Washer, large flat stainless nut washer, and a 15/16 prop nut. Be certain the nut is a "Nylock" nut as there are no other locking mechanisms on this style prop shaft. Be certain to adequately tighten the prop nut---put a 2 X 4 between the prop blade and anti-ventilation plate then tighten the nut grunt tight.

If your prop shaft has the extension. the flare washer and tailcone look nice. In either case, the prop shaft sticks out about 1/8 inch from the prop hub and a spacer or several thick washers are needed. The props you need are for the 4 inch gearcase. You can use any number of 13 inch diameter, 15 spline props from Michigan and Mercury. If your prop shaft does have the extension and you elect to not use the tailcone. put a small bolt through the hole in the extension. It will keep the nut from sliding off in the event it loosens

You can use stainless or aluminum--I prefer stainless. If you buy a Vortex and possibly some other aftermarket brands, you will need to remove the circular anode. The prop webs will hit it and you will not be able to tighten the prop nut.
 
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khoonie

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Jun 22, 2005
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Re: Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacin

Thanks Frank, jestor 68 and BonaireII. I believe these are the parts that you have suggested, Frank:

http://forums.iboats.com/images/attach/jpg.gif

My previous prop was stainless steel and I believe it was 13.5 inch p17. Which pitch would you recommend to attain quicker hole shot (with a heavy load)? 15,17 or 19 - or will it matter? Also, two final questions: 1)That prop nut costs 10 bucks and you must buy 2 of them.... Wouldn't any 15/16 nylock washer work? 2) In your opinion, since I did not hit anything, is it most likely that the nut had loosened to the point that it simply spun off and then, if I put the engine in reverse, the whole assembly just spun off into the abyss? (I will always check the nut for tightness from now on)

(Click for larger image)
 

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Frank Acampora

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Re: Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacin

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Vibration can loosen the nut. You do not need to put the engine in reverse--when you slow down, water pressure against the prop will slide it off the shaft.

A regular stainless or bronze nylock nut will do. Try Fastenal, Graingers, or McMaster-Carr if they are down near you. However, I neglected to mention: The standard Mercury spacer Is splined to fit over the end of the prop shaft. A tabbed washer fits the nut and turns with it as you tighten it. When fully tight, you bent one tab into a matching recess in the spacer. This acts like a castellated nut and stops the nut from loosening. If you wish, you can use this.

Now, as to props: it really is difficult to recommend a prop with no data. To be at least in the ball park it is necessary to know the RPM at wide open throttle with the current (lost) prop. " You can not get to where you are going without knowing where you are starting."

Now, having said that, If you are moving a heavy hull and either the hole shot is poor OR you feel the engine is bogging or not attaining full performance, a 15 pitch will give a better hole shot (acceleration) and higher RPM. I must stress though that without a tach, changing pitch will be a gamble and you may be dissatisfied and/or waste money on a prop. If you can borrow one to test first, that would be the way to go.

More photos of prop choices. The last shows modifications needed to mount a very high rake Ballistic prop. Notice the anode that was removed in the upper left hand corner.
 
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Frank Acampora

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Re: Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacin

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Here is a photo of the bronze mercury spacer.
 

khoonie

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Jun 22, 2005
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Re: Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacin

Thanks for the photos! I appreciate your knowledgeable advice. I believe I will have the engine checked out by a mechanic before I buy the propellor/hardware. The engine has problems. It started missing last time out before the prop loss, but I was on a week long vacation/family trip away from home and hoping it might be a fuel issue, I just added some seafoam and ran it anyway. After fogging the carb for winter and having it sit for a few months I took it out to see if it was still missing. I started it at home first and sprayed it with carb cleaner, put in a fresh tank of gas with seafoam and then took it to the lake. It was still missing, but would occasionally "kick in" and run fairly well. Then I lost the prop. After researching here in the forum, I decided to check my plug wire/boot connections - and sure enough one of them was badly corroded and may have not been making the connection at all. I have replaced all of the plug wires/boots now, but I fear I may have run the motor without one of the plugs long enough to possibly have ruined one of the cd modules (I think that is what they are called). I suppose that would be a topic for another thread if I decide to take it on myself, but otherwise I guess I will have a pro check it out. Only problem is it may be out of commission for prime fishing season, as most times when I take it to someone it stays there 6 weeks or more! (Another story - the place I last took it to kept it to assess a tilt/trim issue and after 6 weeks said it could not be fixed, but would have to be replaced with a new 500 dollar unit. I took it home, got some help on this forum and fixed it myself by replacing two brushes at a cost of $2.50- I won't be going back there!) At any rate it makes good sense to solve the engine problem before buying a new prop anyway, if the engine problem is going to be too costly, there would be no need to buy a new prop. I bought the boat (1988 Bayliner Bass trophy fish/ski) used back in 1997 and have put a tremendous amount of time and no small amount of money in it to keep it going, but I may be at a crossroads here. Despite all the problems, I have grown fond of the boat and have learned a lot as well. Thanks again for your help. Without this forum, I would have given up and sold the boat years ago.
 

Frank Acampora

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Re: Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacin

If you decide you want to trouble-shoot the engine, post your problem or question over on the Force/Chrysler forum. These engines are so simple that almost anyone can do almost any repair themselves--no sense having the boat tied up all season at a marine mechanic and you can also save quite a bit of money.
 

khoonie

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Jun 22, 2005
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Re: Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacin

Will do, Frank. I am encouraged. Thank you Frank, jestor68 and BonairII for all the help! When I get everything working I will revisit this thread and let you know how it all worked out. Anchor's away!
 

khoonie

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Jun 22, 2005
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Re: Prop/all hardware on 1988 Force 125 lost in 160 feet of water! Advice on replacin

I wanted to follow up on my progress with the prop replacement. I decided, after a lot of worrisome consideration, to replace my prop with a 4-blade Quadrajet 13 X 17 prop designed for a heavy boat in order to improve hole-shot and also designed for cruising efficiency over top speed. These are the things I hope to improve with the replacement propeller. Ordered it from Propco as jestor68 recommended and have been very pleased with their company all around, but especially with their customer service help. The engineer that designed the Quadrajet prop personally helped me with my choice and also helped me troubleshoot a problem encountered with the shaft, which was not standard size or thread. I found out that the prop hardware originally included with the original configuration had called for the castellated washer with the tabbed washer insert that fit the standard prop nut perfectly. However, mine had apparently been modified to just use a standard washer and a nylock nut, with no safety feature to keep everything on in case you let it get loose. This is apparently what happened to me. I had not periodically checked the nut for tightness and it probably had loosened to the point that it finally spun off. Without a cotter pin or a castellated washer, the rest of the hardware and the prop just slid off into the lake. That is why I decided to go back to the castellated washer configuration - it would be very difficult to lose EVERYTHING again with this hardware configuration. This is the one that Frank Acampora mentioned.

So I have it on now and I will update this thread with my report on how the prop works when I take the boat out in a week or so. Thanks for all the good advice, everyone!
 
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