125 force 89 arriva 20' boat help me please

[dieselguy]

i recently purchased a 1989 bayliner arriva and it happens to have a wonderfull 125 force on it the motor seems to run very well its got 150 psi in all four cyl starts right up idles fine none of which are my problem when you punch it, it bogs and takes a while to wind out its fine at top end speed. i have a 13x17 prop on it i have pulled the carbs cleaned them replaced all plugs checked spark im at a loss im a mechanic and this ones driving me insane

 

[pnwboat]

Re: 125 force 89 arriva 20' boat help me please

What kind of RPM's are you turning when it's wide open? Have you checked the timing?

One other possibility since the boat is relatively new to you. Might want to check to see if the floatation foam under the deck is water logged. This can add hundreds of pounds of weight to the boat causing sluggish performance.

 

[roscoe]

Re: 125 force 89 arriva 20' boat help me please

Is this your first 2 stroke outboard. They do tend to bog a little when tuned properly.

If they didn't, it would be too lean on the air/fuel mixture, and be short lived.

Prop the motor so it turns 5000 rpm at wot.

 

[jerryjerry05]

Re: 125 force 89 arriva 20' boat help me please

Fuel pump.The diaphram is probably bad.
Ethanol is messing up a lot of things with outboards.
It delaminates the inside of older hoses.
When you removed the carbs did you look at the reeds?
The floats set right?
Find the link and sinc thread Frank put up.J

 

[dieselguy]

Re: 125 force 89 arriva 20' boat help me please

timing wise its hard to tell in the manual it states to remove all plugs jumper the neutral saftey switch and have it at wot im a car / diesel tech and every thing i have ever timed has hit dead on with a light this thing is all over the place in water wot hit 4700 to 5000 rpms and when i had the carbs off i checked the reeds do they sell carbon fiber reeds like they do on jet skis? taking the advice of others i found last night i pulled of the fuel pump and checked it out is dried out and where the sping has set over the years has wrinkled it. although it could be the proplem im thinking not likely theres no holes im gonna change it anyways im there might as well more back info on the boat my friend bought it new in 89 and used it one season and its been in his barn ever since its still in like new condition love the boat but im really starting to hate the motor however i took my friend out to show him how i did and he said its how it ran when it was new but im really doubting it i would of took it back to the boat yard where i bought it and said you can have this back

 

[Frank Acampora]

Re: 125 force 89 arriva 20' boat help me please

After setting the carbs ON THE WATER as outlined in FAQ at the top of this page, (Very important so that you don't burn up the engine) if it stilll is a dog (likely) then there are a couple of things you can do.

The 125 is a small bore, long stroke engine. It does not produce power the same as, for example, the large bore 120 and has a different curve. It must be kept at the top of the operating range. It is even acceptable to exceed the top RPM of 5500 by a couple of hundred. I run my 125 at 5900 on a little go-fast hull.

The 125 is regressively geared at 1.76 to 1. Find an old 90 HP lower unit (or some 85s) with 2 to 1 gearing and swap that onto it. Using the same 17 pitch prop, the hole shot will improve, the top speed will improve, and WOT RPM will increase about 400-500. By all means, try to find a good used stainless prop. The same pitch in stainless will increase RPM by 200-400 over the aluminum prop and increase the top speed by about 2 MPH.

Aftermarket reeds are sold, the ones that come to mind are Boyeson, but there are other manufacturers too.

For skiing, on a 20 foot boat, you may just have to bite the bullet, get a 15 pitch prop, and accept the loss in top speed for the added acceleration to pull out a skier. Again, try for a stainless prop. I run nothing else on my Force and Chrysler engines; aluminum is just my emergency spare.

If I read you correctly and the timing is all over the place, then you have a problem with loose linkages. Check for loose bolts and cracked plastic fittings. Since timing is controlled by the flywheel center magnet and trigger assembly, It should be dead on and not vary at all.