power question

[Alexv]

I have (well my dad rather) a 20' bayliner capri with 120HP outboard motor, question: at what speed should it top out? I was trying to do some water skiing on it and it seems a bit slow, and overall also when not towing anything. Judging by the gps I was toping out at 23-24 km/h with 3 people in the boat on a somewhat wavery conditions and 26-27 on plain water in the river. It seems like that motor should propell the boat faster, if my assumption is correct what is the best way about checking up on the motor? can I do it myself or need to take it to some service(Im not afraid to dig in the mechanical devices having fixed most of my car glitches myself)?

 

[gcboat]

Re: power question

Just can't tell you how to fix it but I'll try to steer you into looking for some possible problems.
First off - has this 'no speed' situation been ongoing or did it just happen that day? That needs to be clarified.

Let's simply start with the obvious - check and clean carbs, fresh gas, is the prop new?, possible kink in the fuel line, possible clogged tank vent, fuel to oil mixture correct?, spark plugs in good shape?. There are more but that should be a start for you.

Also, you didn't state the year of the motor or manufacturer. More than likely a Force?

If you do all of the above then go to the compression check.

Let us know how this turns out for you, might help someone else down the road.

 

[Alexv]

Re: power question

thanks I'll give all those things a shot. The problem is ongoing, it was that way ever since we got the boat a couple of years ago. My dad mostly uses it for fishing so he wasn't concerned with speed much...

And you are right the motor is Force, I'm not sure on the year but its pretty old...

Also one thing I thought was odd when driving and moving the accelerator handle(not sure of the proper name) I noticed that the speed starts to increase(motor starts to rev higher) only once I pass the halfway down to full speed mark(haandle is at45 degrees down) so I thought that maybe the cable connecting/regulating the fuel intake is somewhat loose? Could this be an issue? I'll be doing some inspection later this week hopefully and post the results


Ps. I typed this message off of phone so I'm sorry for typos and messed up English.

 

[gcboat]

Re: power question

O.K. That info helped. Remove the cover from the motor - with the engine OFF push the throttle all the way forward ( fast ). Remove the cable connecting pin and pull the cable off. Now see if you can't get it to move forward ( faster ). If there is any additional movement then it is nothing more than a cable adjustment. Possibly though the cable might need to be replaced.
If it is the original cable it should be red. I'm thinking that it only has one adjustment and that would be on the engine end. However, look at both ends and see if there is a little wheel. That would be your adjusting screw.
So you'd need to turn the adjustment screw out ( making the cable longer ).
I'm really hoping that is all that needs to be done.
If you should need a new cable then they can be found all over the internet, maybe eBay would be a good start.
Also check the movement of the throttle box itself. There is a clip that holds the cable tight, it may also have come loose which will cause the cable to move. Actually I'd look there first - then mess with the motor.

 

[Alexv]

Re: power question

So I finally got to twiddle around with my motor on the weekend, I found out that the throttle was actually pushing the regulator to the very end as I saw the stopper on it contact with its designated spot. I did notice though is that the gismo/leaver(so sorry for my lack of correct terms ) wasnt pushed all the way up when i had throttle/regulator at the endmost position, so I found a way to adjust the connector from a regulator inside the motor to the metal plate that actually regulates the rate at which speed is increased so that it was in a little bit more advanced position from the start which rendered me with desired result.
At the full throttle position the leaver was as far up as possible, that resulted in very slight increase in idle rpm but what I also noticed is that my top speed prety much didnt improve at all...when alone in the boat I topped out at about 35-38km/hr on flat water which is what it was before when I was the only person in the boat...Im starting to think that Im fooling myself...maybe a 120HP motor isnt designed to push the boat faster than what it already does....anyone have a similar boat on those forums and has different speed experience? Would puting a 150 HP(which is top HP for this boat as it says on the planc inside the boat, why so low btw?) improve the speed considerably or not?