Is this top speed okay?

S

sand-man

Recruit

Joined

Jun 16, 2003

Messages

5

• Jun 17, 2003

• #1

I have a 1987 bayliner capri with a force 125h.p motor. My top speed with trim up is 30 mph, with trim down 26mph. Does this sound right? I have checked the motor and carbs and everything appears to be working. Fuel is getting to the carbs but am unsure of how much, the bulb does get firm when the motor is running so no clogs. I am completely out of ideas. I also replaced the plugs and checked to make sure all cylinders are firing. My impression was the boat would do around 45mph. Does this sound more accurate or am I way off?

 

N

NathanY

Commander

Joined

Mar 16, 2002

Messages

2,408

• Jun 17, 2003

• #2

Re: Is this top speed okay?

Are you sure you are getting spark on all cylinders? What is the compression? What RPM's are you turning?<br /><br />Low compression will allow a motor to run, and even idle good, but it will be gutless on top end.<br /><br />Being over propped, will not allow the motor to turn enough RPM's to reach max speed. <br /><br />What kind of weight is in the boat?<br /><br />These are a few of the things you need to check.

 

S

sand-man

Recruit

Joined

Jun 16, 2003

Messages

5

• Jun 17, 2003

• #3

Re: Is this top speed okay?

I'm pretty sure I'm getting spark, what is a sure fire way to check? I just talked to the guy who owned the boat before me and he said he had it up to 45. does this sound right? Also would cam 2 gas help or hurt the motor?

 

roscoe

Supreme Mariner

Joined

Oct 30, 2002

Messages

21,665

• Jun 17, 2003

• #4

Re: Is this top speed okay?

What is cam 2 gas??<br /><br />You need to check how far the spark will jump across a gap to see if you are getting sufficient spark. It should jump approx 7/16"<br /><br />What rpm are you achieving at Full throttle?<br /><br />Check the compression on each cylinder.<br /><br />Do a thorough decarb on the engine.<br /><br />What size is your boat?

 

S

sand-man

Recruit

Joined

Jun 16, 2003

Messages

5

• Jun 17, 2003

• #5

Re: Is this top speed okay?

Not sure what cam 2 gas is, someone else suggested it. <br />Plugs are flat sureface, no gap.<br />Not sure of rpm's no gauge sounds pretty high though.<br />It's a 19 foot bayliner.<br />Does the speed sound slow or is that normal?

 

T

TELMANMN

Chief Petty Officer

Joined

Jun 9, 2003

Messages

465

• Jun 17, 2003

• #6

Re: Is this top speed okay?

19', is it fiberglass or aluminum? What is the max motor on the plate. If 2/3rds. of the rated then with everything working correctly it should plane and run.<br /> If no tach. does it have a speedo or are you using a gps? How did the person you buy it from come up with the 45mph?

 

S

sand-man

Recruit

Joined

Jun 16, 2003

Messages

5

• Jun 17, 2003

• #7

Re: Is this top speed okay?

It is fiberglass, It has a speedo and fishfinder which both max at 30mph. not sure what you mean by What is the max motor on the plate

 

S

Solittle

Fleet Admiral

Joined

Apr 28, 2002

Messages

7,518

• Jun 17, 2003

• #8

Re: Is this top speed okay?

sand-man - Do yourself a favor. Before you start adjustin this or replacin that - get yourself the shop manual for you motor.

 

H

Hooty

Rear Admiral

Joined

Oct 2, 2001

Messages

4,496

• Jun 17, 2003

• #9

Re: Is this top speed okay?

...and a tachometer.<br /><br />c/6<br /><br />Hooty

 

B

boating brad

Petty Officer 1st Class

Joined

Jun 7, 2003

Messages

201

• Jun 17, 2003

• #10

Re: Is this top speed okay?

yea tach is important, but if im right you have a chrysler force motor. i'll tell you my experience i have a 85 14ft bayliner capri it came with a chrysler force 50hp the guy i got it from said it would run 35mph, "lie" it would do 27 max. so i put a 83 evinrude 50 on it and i took it this weekend and it did 40mph.<br />i have been told by several people that chryslers were over rated in hp. so my guess is that 125 and a 19ft boat, 30 is about right maybe 35 but i would be very surprised at 45.

 

D

Dhadley

Supreme Mariner

Joined

Feb 4, 2001

Messages

16,978

• Jun 18, 2003

• #11

Re: Is this top speed okay?

Get a tach. Cam 2 is racing fuel. It comes in several octanes, some with lead. All will decrease your top rpm's.<br /><br />Good luck!

 

K

KCSmith0708

Cadet

Joined

Aug 8, 2002

Messages

19

• Jun 19, 2003

• #12

Re: Is this top speed okay?

 

K

KCSmith0708

Cadet

Joined

Aug 8, 2002

Messages

19

• Jun 19, 2003

• #13

Re: Is this top speed okay?

45MPH? Maybe when he was trailering her.<br /><br />I also have a '88 Force 125HP on a 19' Bayliner Capri. Here's a few simple and inexpensive things to do.<br /><br />I installed a new Teleflex Tachometer(20 poles) and tested both 17 and 19 pitch props. I settled on the 17pitch turning 5000 RPM at WOT and get about 39 to 40 MPH. <br /><br />It recently started to hesitating and cutting out at WOT. I cleaned the carb's with Sea Foam Deep Creep spray then replaced the fuel diaphragm and gasket ($4.70) which took about five minutes. The original Diaphragm had stretched out and was not delivering the fuel at higher RPM's. Runs great and it was simple. Try this before touching any carb or timing adjustments, and do invest in a manual. Best regards, Kevin

 

J

Jwill

Petty Officer 2nd Class

Joined

Jun 3, 2003

Messages

134

• Jun 19, 2003

• #14

Re: Is this top speed okay?

Does your boat seem like its going fast than 30 mph? If so your speedometer might be plugged. It seems every boat I've ridden in with a spedometer (only a few) the mph always reads slower than what the boat is actually going.

 

R

RocknReed

Recruit

Joined

Jun 17, 2003

Messages

3

• Jun 20, 2003

• #15

Re: Is this top speed okay?

Force motors rated the horsepower at the head, not the prop. When mercury bought force they changed that and had the horsepower rated at the prop like most other outboard manufactures. If the motor is made pre mercury than a 125 horse is about 100 horses at the prop. I agree with everyone else that you need a tach, that motor should reach 5400 to 5600 rpm's . if you are reaching max rpm's or above you can increase the prop pitch which would increase your speed if you can hold the rpm's. If your not reaching max rpm's you need to drop in pitch, which would probably slow you down. By the way what pitch prop are you using? Hope this helps!

 

W

what200

Petty Officer 2nd Class

Joined

Jul 12, 2001

Messages

162

• Jun 20, 2003

• #16

Re: Is this top speed okay?

When mercury bought force they changed that and had the horsepower rated at the prop like most other outboard manufactures. If the motor is made pre mercury than a 125 horse is about 100 horses at the prop.

Click to expand...

Not sure about that. I think they stayed crank rated until the end. If they didn't, I'd sure like to know how Merc managed to force 20 more horses out of a cross-flow farce.

 

S

sand-man

Recruit

Joined

Jun 16, 2003

Messages

5

• Jun 21, 2003

• #17

Re: Is this top speed okay?

I appreciate everyone's feedback in this string, I am in the process of installing a tachometer. I will get back on the rpms when I have a chance to put her in the water. I have another question. Does anyone know what size prop and what pitch I should use for this style engine? I have tried miwheel.com but don't have all the specifics they need. It would be alot easier if someone had the same model engine to let me know. I am looking for max speed.<br />1987 force 125 h.p on a 1987 bayliner capri with cuddy cabin. Thanks for all the replies.