88 Force 85hp (3 cylinder). Engine sputters under heavy acceleration from idle.

[DunbarLtd]

Dunbarl .... find a factory service manual for your engine.which is the best.
Check at Ebay they will come up sometimes.
Seloc and Clymers are good in some parts (Clymers the best of these two in my opinion) but they will carry out all models and Hp range and then they are not so detailed.

I think the factory manual also contains the high speed jets setting depending which elevation/altitude you are in.
The high speed jets are fixed and you have to change them if you go to a higher or lower that the jets are for.

The high speed jets manage a big range in elevation until you have to change them.

My model is 856-X8A Im assuming I need the "A" Manual. I see some on ebay now. They have a b and c manuals.

 

[jerryjerry05]

MANUALS
Clymer or Seloc has some good advice but compared to the factory books, they make
good outhouse reading and if you run out of tp then you have something to use.

I thought I'd posted Tillitson was still in business.

The difference between the carbs.

WE 18-1A for top carb and middle and bottom are WE 18-2A.
The only difference is the fuel connections and the throttle connections.
Carbs are probably Tillitson​

 

[The Force power]

My model is 856-X8A Im assuming I need the "A" Manual. I see some on ebay now. They have a b and c manuals.

make sure; they sell you a repair manual and not a parts manual & the years of your motor is important for an accurate manual
and yes it's a A-model

 

[DunbarLtd]

make sure; they sell you a repair manual and not a parts manual & the years of your motor is important for an accurate manual
and yes it's a A-model

Well now im paranoid. All the ones I see say service manual. Its possible some of those are parts manuals? WTF...

 

[DunbarLtd]

MANUALS
Clymer or Seloc has some good advice but compared to the factory books, they make
good outhouse reading and if you run out of tp then you have something to use.

I thought I'd posted Tillitson was still in business.

The difference between the carbs.

WE 18-1A for top carb and middle and bottom are WE 18-2A.
The only difference is the fuel connections and the throttle connections.
Carbs are probably Tillitson​

Yes. The only difference is the fuel connections. I noticed that right away when looking at them. Thanks again Jer...

 

[Nordin]

If it is a paper book and says service manual it is not a parts manual.
I know there are CD copies out there and they can be copied from all kind of manuals.

Stay with a paper factory manual and you got the best information you can.
They can cover some other Hp range such as the OB4642 which covers 85, 90, 120 and 125Hp 1988 thru 1991 A models.

 

[DunbarLtd]

If it is a paper book and says service manual it is not a parts manual.
I know there are CD copies out there and they can be copied from all kind of manuals.

Stay with a paper factory manual and you got the best information you can.
They can cover some other Hp range such as the OB4642 which covers 85, 90, 120 and 125Hp 1988 thru 1991 A models.

Thats exactly the one i found. I ordered it in fact. Might take like 2 weeks though. Hopefully i get it sooner! Thanks for the help.

 

[DunbarLtd]

Until you get the rpms set right??
You can adjust the air screws all day and not accomplish the task?
Factory recommends 1 turn out.
Mine ran great for YEARS at that setting.

I have a purple wire connected to the terminal block for tachometer.It is ran up to the dash but capped. If i use a portable tach can i just wire it to that purple wire or do i have to wrap it around the plug wire?

 

[Nordin]

The purple wire is for the tacho and it is the stator/alternator signal.
It is a AC 12V signal and you have to have a tacho that handle a 20 pol stator signal (I think your engine has a 20 pol stator).
Later Force with Mercury thunderbolt ignition use 12 pol stators.

You will not hurt the tacho if it can not handle 20 pol stators but the readings will not be right.

If you have tiny tach or that kind of tacho you have to use the signal at the plugs (wire wrapt around the plug),
You can not use the purpule wire.

 

[DunbarLtd]

The purple wire is for the tacho and it is the stator/alternator signal.
It is a AC 12V signal and you have to have a tacho that handle a 20 pol stator signal (I think your engine has a 20 pol stator).
Later Force with Mercury thunderbolt ignition use 12 pol stators.

You will not hurt the tacho if it can not handle 20 pol stators but the readings will not be right.

If you have tiny tach or that kind of tacho you have to use the signal at the plugs (wire wrapt around the plug),
You can not use the purpule wire.

Ok thanks for the heads up.

 

[DunbarLtd]

The purple wire is for the tacho and it is the stator/alternator signal.
It is a AC 12V signal and you have to have a tacho that handle a 20 pol stator signal (I think your engine has a 20 pol stator).
Later Force with Mercury thunderbolt ignition use 12 pol stators.

You will not hurt the tacho if it can not handle 20 pol stators but the readings will not be right.

If you have tiny tach or that kind of tacho you have to use the signal at the plugs (wire wrapt around the plug),
You can not use the purpule wire.

I took the boat out yesterday. I did some hole shot starts after i adjusted the mixture screws out to 1/ 1/8 and i noticed something.

If I let the motor idle in place for maybe like a minute and then tried a holeshot it would sputter, but after i did a few holeshots one right after another, the sputter will go away. Until i let it sit and idle again. Then rinse and repeat. I was able to demonstrate this over and over for 10 minutes. It would always sputter out when it sat and idled.

It cleared up relatively quickly each time. And there was no miss or sputter at any other speed. Just during a hole shot and only after it idled for a bit. The longer it idled the worse it got.

Also this thing shakes like a ***** at like 6mph. It does not like that speed at all.

But, as far as the holeshot sputter Im assuming its the spark plugs loading up.

What can I do now to correct the problem? Any ideas???

 

[Nordin]

It looks like the plugs loading up while idling.
Try to set the air/fuel mixture at 1 turn out or 1 1/16 and see what happens.

What fuel/oil ratio do you mix? 50:1, maybe the mix is to rich. 50:1 is the correct ratio.

 

[jerryjerry05]

Did you ever get the idle set right?
800 in gear in the water.

 

[DunbarLtd]

Did you ever get the idle set right?
800 in gear in the water.

What would the idle speed have to do with it sputtering when holeshot?

Could you explain because it doesnt make sense to me. The idle is fine. No tach but when put in gear it doesnt die. And no loud clunk. I had to readjust after i messed with the air screws and i had to raise it a bit but barely. Im sure its gotta be somewhere around 7 or 8. I cant find a tach anywhere.

Anyways like I said whats the idle speed have to do with holeshots? Its doing the same thing it did when i had the air screws set to 1 turn out. I forgot to do it but next time im going to take the airbox off and see if the carbs are spitting, which i doubt they are but the reason is because i removed the carbs and cleaned/checked floats and noticed the inside of the airbox was wet. I assume this is either because reeds are failing or the carbs leak when tilted all the way up for storage.

Or maybe the carbs are flooding even though ive checked the needle/seat when had carbs apart and they sealed just fine.

There is always a little puddle in the bottom of the air box when i get home. This could just be because of the recirculation hose or the carbs are flooding or spitting. Also the gaskets from airbox to carbs are always wet like they are constantly getting soaked with fuel/oil. Doesnt see right to me. They are new gaskets. So i have that issue to figure out as well.

I do 50:1 mix. New plugs as well. I didnt check compression because i forgot my grounding wires. That will be next trip for sure.

 

[racerone]

Set the slow speed needles 1-1/2 turn out and test run.

 

[DunbarLtd]

Set the slow speed needles 1-1/2 turn out and test run.

The service manual showed up in the mail finally and it says to set @ 3/4 out and do the turn in and out till it pops deal. Then set it in the middle.

Then it says do holeshot (wot from a idle speed) tests and "if the engine stumbles rich on the acceleration lean out the carbs by 1/16 turn and repeat step 4 until the engine accelerates without hesitation."

Step 4 basically says after you get it to pop by turning the screw clockwise, turn it out 1/8 turn(more rich). Then do holeshot test again and if it stumbles then lean it out by turning 1/16 in.

Its saying if it stumbles its too rich. And youre saying to make it even richer. But I havent done the tuning on each carb yet so the middles could be 1 1/2 turns out. I dont know. But it says to lean it out when it stumbles so thats opposite what you are suggesting. Can you explain why? Thanks for the advice.

 

[racerone]

Good luck with your motor .----Just follow your manual.

 

[jerryjerry05]

The motor(idle set at specs) needs to be set up right to operate right

The carbs leak when tilted up thus the black stuff under the motor on the ground.

1990 or 91 the factory said to turn the air screw out 1 full turn and leave it there.
I ran mine like that and had no problems.
BUT!! one customer I had needed to have his turned out almost 3 full turns to just get it to idle???

What's the rpm's at idle, in gear, in the water?

Try cleaning the recirc system?
There are screens in there that clog with carbon flakes.
Clogged screens, can stop the fuel from recirculating and leak out the plenum.
Is the hose still attached to the bottom of plenum?
The crud can block the hose and valve on the bottom of the intake.
ebay

SCREEN F93811

 

[DunbarLtd]

The motor(idle set at specs) needs to be set up right to operate right

The carbs leak when tilted up thus the black stuff under the motor on the ground.

1990 or 91 the factory said to turn the air screw out 1 full turn and leave it there.
I ran mine like that and had no problems.
BUT!! one customer I had needed to have his turned out almost 3 full turns to just get it to idle???

What's the rpm's at idle, in gear, in the water?

Try cleaning the recirc system?
There are screens in there that clog with carbon flakes.
Clogged screens, can stop the fuel from recirculating and leak out the plenum.
Is the hose still attached to the bottom of plenum?
The crud can block the hose and valve on the bottom of the intake.
ebay

SCREEN F93811

I removed the dogbone again and the screen was maybe less than 5% collected with small particles of carbon but no sludge whatsoever. No big chunks. Just small particulates. I doubt that was the problem. I will check the lower hose/valve to make sure it didnt get clogged.

I still am looking for a reliable tach because the tiny tachs jump all over the place and makes it hard to get a decent reading. Ive been looking for 20 pole dash gauges but no luck yet.

Mine is a 1988. Manual says start @ 3/4 turn out and go from there.

Honestly it idled just fine @ 1 turn out. Once I fine tuned the idle speed screw it would go into gear perfectly and idle for as long as i wanted.

Next time out i will do what the manual says and start @ 3/4 and try to fine tune it, then adjust idle speed to the best i can without a tach.

Question: With '88 capri 1750 is there an approx speed that 750-800 rpms should achieve? Because right now after I adjusted the air screws to 1 1/8, the idle speed dropped and it will only do about 2.5-2.9 mph in gear.

Before I did the decarb I set 1 turn out after i rebuilt the carbs and then left alone, i adjusted the idle speed until it wouldnt die when put into gear and i was averaging about 3.2 - 3.6mph (GPS). Whats a good idle speed or does it vary from boat to boat with the same motor? Just curious...

I will check spark and coil with a voltmeter. Manual explains it very clearly and its easy to do. Looks like 210v is normal coming from stator when cranking. Then 40k volts after the coil. Its possible its a bad spark. I will hook up my spark tester to 7/16 gap and see how well the spark jumps.

Ive taken the fuel pump apart and its fine. The valves spring back, the diaphragm is impeccable. But if it was fuel related im almost certain Id have running issues at full speed, which i dont(ie; spitting, cutting out etc)I just have a loss of a couple mph, which in super confusing.

The one thing that stood out last time i tested was after a couple holeshot attempts i immediately got on plane and i saw about a 1.5mph increase in top speed. I know this because i let it sit and idle for about 2 minutes in gear and the got up on plane and it did 30mph max. So it looks like plugs get fouled up but im still not sure whats causing it.

I hope its a simple carb tune or blocked hose...will update soon.

 

[jerryjerry05]

The factory updated the air screw setting in 89/90
They recommended 1 full turn and leave it there.
As far as speed at idle? is different on different boats.
My 21 with twins was used for trolling in the Chesapeake and the waters off Ocean City, Md.
It ran about 2.4 at the rpm setting of 750-800
Then I moved to Michigan and more trolling, slower this time.
Dropped the rpm to 600 on one motor and it ran 1.4
The bad is the motors carbon'd up pretty bad and needed re-ringed.

Sierra 20 pole tach.
Hope it shows?? If not Google 20 pole tach.
https://www.google.com/url?sa=t&rct...121896655471&usg=AOvVaw0A1yqTY8mXXNQ89IKvvuo6