Force 120hp don?t go

Raul

Recruit
Joined
Aug 9, 2007
Messages
3
I?m new on boating and recenty bought a bayliner capri1800ls with a force 120hp. ? can?t get more than 30 mph with 4 people aboard. is this normal ??? Does anybody with a similar motor and boat is getting more ???
Thanks in advance for your comments.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Force 120hp don?t go

Force motors aren't known for their performance.How does it perform otherwise?start easily? Good hole shot? What is rpm and speed at wot(wide open throttle)with one aboard and with 4??See if you can find the demensions on the prop.You could check the compression.get back with results maybe we can figure things out.
 

QuadManiac

Petty Officer 1st Class
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Jul 2, 2007
Messages
391
Re: Force 120hp don?t go

Force motors aren't known for their performance.

Where did this statement come from? I'm sure a whole slew of Force owners will be glad to tell you how 'poorly' their Force motors perform.

My 18' bowrider with a 1991 Force 90 will reach 35MPH (GPS measured) with 500 lbs of crew and a full gas tank, about 39 with just me and a couple of gallons. Several other owners of similar set ups are in agreement.

Are you suggesting, Steel, that if I were to replace my Force with a similar vintage and rated hp Merc or Johnson, for instance, that my speed would improve?
 

Raul

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Aug 9, 2007
Messages
3
Re: Force 120hp don?t go

My motor is 1998, RPM at WOT are just above the 4000, the propeller is 13 x 19 aluminum and the start is easy but the aceleration is poor, it takes several minutes to get the 30 MPH after adjusting the trim.

I?m going to check the boat this weekend with lower load to see what I can get.

Any more suggestions ????
 

QuadManiac

Petty Officer 1st Class
Joined
Jul 2, 2007
Messages
391
Re: Force 120hp don?t go

Well, your WOT RPM wants to be closer to 5000 (4750-5250), is 19 pitch too much prop? BTW, are u measuring speed with pitot speedo or with GPS? My speedo generally reads about 5MPH or more low relative to my GPS, depending on.... what phase the moon is in? I don't know. You know which one I believe!
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Force 120hp don?t go

My motor is 1998, RPM at WOT are just above the 4000, the propeller is 13 x 19 aluminum and the start is easy but the aceleration is poor, it takes several minutes to get the 30 MPH after adjusting the trim.

I?m going to check the boat this weekend with lower load to see what I can get.

Any more suggestions ????

I would say check your compression.If compression is good and you feel the motor is in good tune you might try raising it vertically.If you can gain an inch
or so you might get 2 or 3 mph.But it seems to me once your sure of your condition and setup you may want drop in pitch a little.See if you can find a shop that will let you try props.Some will if you intend to buy.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Force 120hp don?t go

Where did this statement come from? I'm sure a whole slew of Force owners will be glad to tell you how 'poorly' their Force motors perform.

My 18' bowrider with a 1991 Force 90 will reach 35MPH (GPS measured) with 500 lbs of crew and a full gas tank, about 39 with just me and a couple of gallons. Several other owners of similar set ups are in agreement.

Are you suggesting, Steel, that if I were to replace my Force with a similar vintage and rated hp Merc or Johnson, for instance, that my speed would improve?

I didn't say they performed poorly I did say they are not noted for their performance.
And yes I do believe a 90 of most any other brand of carbed 2 stroke will out perform the Force.
Your motor certainly performs well enough and I could be full of hoooey!
 

QuadManiac

Petty Officer 1st Class
Joined
Jul 2, 2007
Messages
391
Re: Force 120hp don?t go

I'll grant you the hooey, since you said it, lol; and I'll hope that mine keeps perfoming as well as it currently does, well into the future! (knock on marine plywood)
 

section8

Petty Officer 2nd Class
Joined
Jul 27, 2007
Messages
120
Re: Force 120hp don?t go

why all the fuss? that sounds like a good top speed to me for that boat engine combo. am i wrong cuz thats what mine gets too
 

baxtr

Petty Officer 1st Class
Joined
Jul 16, 2006
Messages
387
Re: Force 120hp don?t go

I would guess another few mph as long as the motor is fine. Quad is right, your rpm's are too low for WOT. Take Steelspike's advice and check compression, then try different props to get the rpms between 5000 and 5500 at WOT I have a 19' with a 125 force 13 X 17p prop and get around 42 +/- And mine does run great, (but it is a fresh rebuild)
 

Raul

Recruit
Joined
Aug 9, 2007
Messages
3
Re: Force 120hp don?t go

Problem solved. A mechanic reviewed the motor and found that one spark was not working properly, he changed them, compression was fine and he cleaned the carburator.

Now I?m getting 45 MPH and 5000 RPM and aceleration is very good.

yihaaa !!!!

Thanks everybody for your sugestions...
 

QuadManiac

Petty Officer 1st Class
Joined
Jul 2, 2007
Messages
391
Re: Force 120hp don?t go

That sounds more like it! Congratulations.
 

Trevor9751

Cadet
Joined
Aug 18, 2007
Messages
22
Re: Force 120hp don?t go

I am glad you found just that I had the same performance issues with the pretty well identical boat and when opened it up I found water in the pistons turned out it was slowly siezing up and thats wy so underpowered I am glad to hear that your power is better now my rebuilt motor will be here monday and it couldn't pull me out on skis before so hopefully it will now and it is good to hear that it will have alright power to thanx for posting.
 
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