1987 force 125

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dcsjr

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May 14, 2001
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I have a bayliner 18ft with a force 125 ob. the problem is it won't come out of the hole to pull a skier or tuber. It has had a complete engine overhaul and all the electrical (stater included) replaced. with trim down 34 mph with up 37 mph but still (nearly stalls on take off) no power. I've had the boat in most of last year and it seems no one has an answer. any help would be greatly appreciated.
 
JB

JB

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Re: 1987 force 125

hey, dcsjr. What rpm are you turning at w.o.t.? What prop do you have on it (pitch)?<br /><br />Standing by.<br />JB
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dcsjr

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Re: 1987 force 125

the boat has had a 17 and a 19 prop on it. It runs around 5000 rpm with the 17 neither does much better.
 
JB

JB

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Re: 1987 force 125

Ahoy, dcs. Neither of those props is allowing your engine to rev to the top of operating range, which I would expect to be 5500-6000rpm. 37 mph also seems a bit slow to me for a 125. I am surprised that you don't notice a difference with the 17" prop.<br /><br />General rules for propping suggest that a 15" prop will get your w.o.t. up to the mid-5000rpm range and top speed nearer 40, as well as improving your hole shot. I don't know your boat, but I think it would be worth a try to beg/borrow a 15" and try it out.<br /><br />Good luck.<br />JB
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dcsjr

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Re: 1987 force 125

JB I was able to look up the prop designed for the boat and the book said 17 max power and 19 for speed. the motor has a max 5500 rpm. It is not an easy year to find a prop for. It's a US Marine motor so Chryler props don't work and merc props (89ish) don't either. Most dealers do not carry this prop so I can't just try a prop. The service places where I took the boat to, said that the 17 was the answer and but there was no noticable difference out of the hole just a higher rpm and lower top speed. I've noticed in another post that someone mentioned to use premium gas only in these engines does that make sense? As far as only 37 mph, I've talked to people who have owned a boat like this that do 42-45 mphs. If anyone owns a boat like this could you tell me how fast your boat goes and at what rpm thanks. ps thanks for imput jb.
 
rogerwa

rogerwa

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Re: 1987 force 125

YOu may want to look at miwheel.com, which is the site for Michigan Wheel. YOu can use the prop selector wizard which will guide you for your particular application. For a 17' to 20' boat, it recommends a 15". For 16' to 18' it recommends a 19" prop.<br /><br />Also, boatfix.com sells these props at great prices..
 
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sony2001

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Mar 17, 2001
Messages
607
Re: 1987 force 125

dscjr; I have a Bayliner 88, 125hp. We have<br />the same generation engine. Three weeks ago I shopped for a new prop and three suppliers<br />listed the 15" prop for full load and skiing.<br />Its not until the next younger generation<br />thats its raised to 17" for the above conditions.<br />Last trip out with a clean hull and 19" the<br />indicated speed was 34mph,tilt down.<br />RPM I'm not sure but sounds like near 5000.<br />Premium I use and its 92 octane here. On<br />thursdays it the sams price as mid-range.<br />If I need gas on the lake I don't hesitate<br />to buy some regular to get home. At those<br />RPM's and loads I don't want to risk preignition or detonation, the boating season <br />is too short.<br /><br />------------------
 
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sony2001

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Re: 1987 force 125

dcsjr; read the posting on April 18,2001 under the Username RJA.<br /><br />------------------
 
D

dcsjr

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May 14, 2001
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Re: 1987 force 125

Thanx sony2001 for the info. Do you know where I could get a decent manual for this engine?
 
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sony2001

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Mar 17, 2001
Messages
607
Re: 1987 force 125

dscjr; Force outboards 84-88 ,all, by Solec<br />Publications, 10693 Civic Center Drive, Rancho Cucamonga Drive, California 91730-3804 or buy it from a reseller on the web.<br /><br />------------------
 
A

a1physics

Recruit
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May 9, 2001
Messages
5
Re: 1987 force 125

I have same Same Problem to.My Boat is a 86 Bayliner Capri 18", It is all it could do this past weekend to pull a skier out of the water.I just purchased a motor for my trim and am finally getting a taste of the great outdoors.
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12Footer

12Footer

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Mar 25, 2001
Messages
8,217
Re: 1987 force 125

If it nearly stalls at take-off, it could be gummy carb/reeds/rings from sitting. Try running some decarb thru it. It's a good idea to do this anyway, once a season.<br /><br />Tight lines, Tall roosters
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B

bobmoore

Petty Officer 2nd Class
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Mar 25, 2001
Messages
109
Re: 1987 force 125

i got a 21ft. maxum with a 120 force l-drive 13.5 x15 prop , let me tell you it jumps out of the hole ,and top speed is about 38,at 5300 rpm,s with the trim a little to smooth the ride ,sounds like the carb rod between the two carbs might be off ..good luck
 
C

cyberplumber1

Cadet
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May 28, 2001
Messages
10
Re: 1987 force 125

You must run at least mid grade fuel. Try a 17" four blade prop instead of three blade. Also have a compression test done. Check to make sure all the carbs open all the way at full throttle, you can do this without the motor running. Also check to make sure the timing isn"t retarded to much. Also make sure the fuel air idle mixture screws are set at one turn only.Use only the factory spec spark plugs.One more thing, look at the boat weight distribution, is there any weight that is in the back that you can transfer to the front? Good Luck
 
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