'88 Force 125 is Pokey..

[Speedtek]

My problem:
I cannot get my boat on plane, RPM does not go above 3000. It has (on two occasions) kicked up to 5000 RPM but then loses it and max's out at 3000. Its frusterating obviously.

Here's the info:
'88 Force 125 horsepower
Model: #1251X8C

Actions taken:
* Compression test - All cylinders ~150 Lbs.
* Link/Sync and Timed per manual
* Rebuilt carbs
- New gaskets, new float needles, adjusted all per spec.
- New fuel pump diaphram
= ran from sperate tank with new line, and no difference.
* New Plugs
- Plug condition - Oily and carboned
* Tested all electrical components per Seloc specifications - all windings/coils within spec.
* Exhaust boot was split, sealed with high temp and duct tape, no more leakage into cowl.
** The bushing at the end of the spring appears to have been overheated or worn, and is protruding into the idle relief holes, could this cause an exaust restriction of some sort?

Thanks for any advice!

 

[Frank Acampora]

Re: '88 Force 125 is Pokey..

Most likely the plastic bushing has melted some. Since it is the idle relief circuit, most exhaust exits the snout while at plane, but yes, it could be causing some of the problem. Should not be more than 10 bucks to replace it.

Asa for intermittent high RPM, it still sounds electrical. Check for frayed wires or intermittent shorts in the coils or grounds. Poor grounding causes a LOT of headaches and can be very difficult to diagnose.

 

[chitownborn]

Re: '88 Force 125 is Pokey..

i had the same issue, drove me nuts. check your coils, i checked mine and everything ohmed out to seloc manual specs, it took going out on the lake, with a timing light and the cowling off and changing the timing light from one cylinder to another at wot to find one of the coils not firing at all and another firing intermintant .but when idling all were firing just fine might be something to look into

 

[john from md]

Re: '88 Force 125 is Pokey..

It sounds to me like you are losing one cylinder. The best way to check is with a timing light or even an inductive tach. You will need too people so that one can drive and the other watch the indications. If the cylinder is cutting out you will have no or erradic readings on the tach or erractic or no flash on the light.

Once you find which plug is firing intermittantly, switch the leads on the CDI unit and see if is is that. If it moves, it is the CDI, if not, it is probably a coil.

Make sure the person working with the inductive clamp is not a jumpy kind of guy. You can get a high tension bite when doing this kind of stuff and you don't want to jerk your arm into the flywheel.

Good luck,

John

 

[Speedtek]

Re: '88 Force 125 is Pokey..

Thanks for the replys!

I did check my spark with a timing light on the lake and did not notice any dropping on a particular cylindar - I did pull the plug wire off and the spring that held it to the plug parted ways from the wire. I replaced the terminal ends but did not see any real change, so mabey the wires are corroded internally.. I may just replace the coils just to be sure.

Another thing - When I first took the boat out on the water, I made the mistake of measuring my oil/gas ratio wrong and added probably 5x the oil than I should have.. needless to say the motor was quite a fog machine. Would this gum up some internal passages? Fuel recirc or whatnot? If so what can I do to check it all and clean it?

 

[john from md]

Re: '88 Force 125 is Pokey..

The extra oil may be the cause of your problem. If you don't have the right mixture of gasoline and air, you will loose power. Do you have an inboard tank? If so, you are kind of stuck until it gets diluted through normal use.

I would not go changing anything until you get down to a proper mixture and then see how the engine is performing.

John

 

[Speedtek]

Re: '88 Force 125 is Pokey..

I've ran three tanks through since then, but i did notice that the cylindars and plugs are always a bit oily and gritty. I should probably do a mega decarb

 

[john from md]

Re: '88 Force 125 is Pokey..

That is a good idea. If you have the capability, blow out all of scavenge lines and ports. If they get clogged up, the engine will run too rich.

John

 

[Speedtek]

Re: '88 Force 125 is Pokey..

Update - Did a full decarb - seafoam, smoked out the neighbors ect.. after smoking stopped i replaced the plugs and went to the lake.

The boat ran like a sewing machine, sounded great, but still topped out at 2500-3000 rpm. I cannot find anything obvious and may just bring it into the shop to have them take a look at it.

Ugh!

 

[heycookieman]

Re: '88 Force 125 is Pokey..

Want pitch prop is on the motor?

 

[Speedtek]

Re: '88 Force 125 is Pokey..

The prop is a 13.25x17 - its what the manual recommends.

A bit of an update, I took it to a shop a few weeks ago and they said the terminals connecting the the plugs were bad and arcing, fair enough - so they replaced the ends, the boots, and the plugs. Said it was fine now, and I picked it up.

Finally was able to get to the lake the other day, and low and behold, 2500-3000 RPM - I obviously do not want to take it back to the shop for them to shotgun random fixes at it, it gets expensive that way.....

It's getting mighty frusterating... any clues??

 

[JDP]

Re: '88 Force 125 is Pokey..

This is just a shot in the dark but have you looked at the reed valves? When I was having the same sort of problem with my 125 it was suggested to me to check them.

 

[Speedtek]

Re: '88 Force 125 is Pokey..

Ok, fixed it!!! This problem has been haunting me since I bought the boat a year and a half ago.

I went through the wiring diagram in the manual and found that the wires coming from the stator to CDI#2 were reversed. I swapped them around, started the boat, and whammo 5000 rpm in gear!!

It makes sense now though, you would still see good spark on all cyl's as well as good compression, fuel flow, and all the electrical components would test out OK. Except, cyl's #3 & #4 would be firing out of sequence.

If anybody else is having mystery problems like this, it is something to check out.

Thanks for the input, cant wait to get it on the lake now!! Woooooohooo!

 

[Speedtek]

Re: '88 Force 125 is Pokey..

Well, in the end it turns out that I was semi-correct. Fixing the wiring only brought the boat up to 3500 RPM at WOT - though the engine ran smooth as a sewing machine.

Went back to basics and reviewed the whole system. Turns out that I have a 13x17 Piranha prop (plastic/composite prop) thats essentially in brand new shape. Anyway, I read some posts that there has been some performance issues with these props. I took out an aluminum prop that came with the boat, same size, 13x17, and mounted it on the boat.

Well, I'll be damned. The boat jumped out of the hole for the first time since I've owned it, it achieved 4600-4800 RPM at about 40 mph, like a new boat!!!

The prop was the last thing I'd expect for a 1100 rpm difference, but there it was. I would not recommend this prop for any boats with a decent amount of horsepower. I'm not sure if it's flex or what, but it was the problem.