hard start 1989 force 125hp good info

[slx12001]

I have a 1989 Force 125hp b model. I have owned this engine for about 3 years. I have it running great, (kind of) idles great in gear, Has good mid range and good top end, everything about running is good. A little history. I have rebuilt both carbs with floats etc 2 times since owing always blowing out all passages and making sure the circuits are working with carb cleaner blowing through. I have rebuilt the fuel pump 2 times. I have changed every fuel line more than once. I have a fuel filter before the fuel pump. I have changed #1 and #2 piston/rings due to failure beginning of last year. All 4 cylinders have about 140 psi. Ignition all tested with dva The timing is spot on. The boat get used a couple times a week or more since buying about 3 years ago. Everything works very well...Except it's hard to start. It starts the first time out usually better then later in the day. I jump around alot fishing so I may start the engine 8+ times in a day. Starting consist of first pumping the primer bulb which is usually already tight. Then out of gear high idle with choke on off crank more then after maybe 10-25 seconds of various tries it will fire. It usually always will lean pop and sometimes die 1-2 times unless I immediately put it in gear with a little throttle. (Should not be lean popping after tries with choke on in my opinion) After about 10 seconds of running I could put in forward at idle and go all day if I wanted. What is strange is the lean pop then die when starting after the choke has been on. I have verified the butterflies for the choke are fully shutting and holding shut. Just looking for another place to look. When it's running it runs great from idle in gear to wot. I have spent more hours then I would like to share on this engine. When I got it it would not idle in gear, had top end rpm issues etc. Any advise recommended.

One thing that I would like to add to this is that this engine use to smoke like mad. My last 3 tanks have been [h=1]Pennzoil XLF Marine Synthetic Blend Engine Oil[FONT=Arial, sans-serif] [/FONT][FONT=Arial, sans-serif] It smokes about 75% less now. I have tried many oils trying to reduce smoke. I gave this cheap oil a try after hearing others talk about it and it really worked for me. It doesn't smell to bad either. [/FONT][/h]

 

[jerryjerry05]

Possible float adjustment.
​Possible the air screws not set right.
What's the idle rpm's in N Should be 750-800 in gear(closer to 800) or 1100-1200 in N

Excess smoke comes from starting and stopping and hard starting and running slow.

 

[slx12001]

Possible float adjustment.
​Possible the air screws not set right.
What's the idle rpm's in N Should be 750-800 in gear(closer to 800) or 1100-1200 in N

Excess smoke comes from starting and stopping and hard starting and running slow.

Where is the air screw? All I see is a fuel screw that runs best at 1-1/8 . Float has been tried a little high a little low and level with body all the same. idle rpm is about 800 in gear and 1150 out. I run for enough time to clean out between starts. None of that is the problem though as after it starts and has a few seconds to run it's fine. Starting is the issue. Also if i try to start a couple minutes after turn off it starts at a touch of the key. Only after 10 minutes or more does the hard start occur.

 

[tommarvin]

We have a 125hp, What we have learned, don't squeeze the primer bulb unless it has not been used for a week.
If longer only squeeze the primer bulb one time and stop, the first time you turn the key you choke the motor, always have the throttle on fast idle.
The second time you turn the key, don't choke, if no start you choke on the third time you turn the key.
We use Penz XLF marine syn, from walmart for 17 bucks a gallon, a lot less smoke, you don't want to stay in one place with a 2 stroke.
Long story short it's very easy for us to flood the motor, never pump the primer bulb or choke after the motor starts, our motor always gets flooded..
This could be when old ignition parts get hot/overheat they need to cool down to start working again, it seems to be 10-15 min of cool down. before the motor will start again. It's a frustrating slow death of an ignition part, which part IDK your very good at motor diagnosis , maintance, and fixing.
I agree the lean pop die is bizarre , we fast idle up immediately if we hear a lean pop and the motor is still kind of trying to start .
A

 

[slx12001]

We have a 125hp, What we have learned, don't squeeze the primer bulb unless it has not been used for a week.
If longer only squeeze the primer bulb one time and stop, the first time you turn the key you choke the motor, always have the throttle on fast idle.
The second time you turn the key, don't choke, if no start you choke on the third time you turn the key.
We use Penz XLF marine syn, from walmart for 17 bucks a gallon, a lot less smoke, you don't want to stay in one place with a 2 stroke.
Long story short it's very easy for us to flood the motor, never pump the primer bulb or choke after the motor starts, our motor always gets flooded..
This could be when old ignition parts get hot/overheat they need to cool down to start working again, it seems to be 10-15 min of cool down. before the motor will start again. It's a frustrating slow death of an ignition part, which part IDK your very good at motor diagnosis , maintance, and fixing.
I agree the lean pop die is bizarre , we fast idle up immediately if we hear a lean pop and the motor is still kind of trying to start .
A

I have worked on many Chrysler/Force outboards over the years. I had an 85 hp tripple running great for many years. This engine has not always had the hard start issue and I believe I have it fixed. The fuel recirculation system was dirty. I have not had the recirculation system apart since I bought the engine. I will know for sure in a few days when I can get it out on the water. If your flooding the motor by priming the bulb you may want to check the needle and seat in the carbs.

 

[Jiggz]

Do you have the NGK BUHX for spark plugs? Do you know for sure the choke system is working? I mean with the cowling cover off, watch the choke system all the way while cranking the starter over. Did the choke stayed engaged with the starter running?

I had the same problem before and noticed that even though the choke engages when I pushed in the ignition switch, as soon as I turn the switch to "Start" position, the choke unit disengages. I thought the problem was with the ignition switch losing connection on the choke circuit when turned on.

But even with a new ignition switch the problem persists. My solution was to make sure the battery is fully charged before going out. Eventually, I just modified the choke circuit to use a relay so it is directly powered from the battery through the starter solenoid using heavier gauge wire. The existing green wire is instead just used to power the relay. Never had problem eversince with the choke circuit.

Install the clear fuel filter between the fuel pump outlet and the carb's inlet. And make sure it always stays at least half full.

If none of the above solve your problem try decarboning the engine. I have the same exact motor and yes, it has the tendency to lean pop but usually that is only when I have it choked. As soon as it lean pop, then I stop the choke and it always starts the 2nd time even without doing the high speed idle.

 

[slx12001]

Do you have the NGK BUHX for spark plugs? Do you know for sure the choke system is working? I mean with the cowling cover off, watch the choke system all the way while cranking the starter over. Did the choke stayed engaged with the starter running?

I had the same problem before and noticed that even though the choke engages when I pushed in the ignition switch, as soon as I turn the switch to "Start" position, the choke unit disengages. I thought the problem was with the ignition switch losing connection on the choke circuit when turned on.

But even with a new ignition switch the problem persists. My solution was to make sure the battery is fully charged before going out. Eventually, I just modified the choke circuit to use a relay so it is directly powered from the battery through the starter solenoid using heavier gauge wire. The existing green wire is instead just used to power the relay. Never had problem eversince with the choke circuit.

Install the clear fuel filter between the fuel pump outlet and the carb's inlet. And make sure it always stays at least half full.

If none of the above solve your problem try decarboning the engine. I have the same exact motor and yes, it has the tendency to lean pop but usually that is only when I have it choked. As soon as it lean pop, then I stop the choke and it always starts the 2nd time even without doing the high speed idle.

I use the champion plugs. Have you had good luck with the NGK's? I put the filter before the pump because when I had it after the pump years ago on a different 85 hp force the carbs would loose their prime due to back filling into the filter. I have thought about wiring and plumbing an omc primer but the way these carbs work is holding me back. I think when the choke system is used it energizes the low circuit with gas as well by pulling (suction) from the float bowl. If it was a snowmobile or similar I would throw a set of mikuni flatslides on and be done. :frusty: I think the design of these carbs are the engines worst enemy. Great Idea wiring a relay. I may do that anyway.

 

[jerryjerry05]

I find no difference between Champion or NGK.
​I have trouble finding the Champion where I live.
I had a 2 sets of Champions last over 10 years and only changed them because I felt guilty

​(it energizes the low circuit with gas as well by pulling(suction) from the float bowl)
The low speed circuit is energized when you squeeze the ball.
Is your choke set right?
They get gummed up and can "half stroke" and not close the shutters.(one good use for carb spray)
Or the choke body needs to be repositioned ??
Every now and again I have to clean the choke tube and piston as it gums up and sticks.

 

[Jiggz]

For some reasons, for me NGK's seems to perform more smoothly than the UL18V especially when idling. Mind you I used the BUHW and not the BUHX. The big difference between the two is the larger gap on the BUHW which is 1.3 mm while the other only has 0.75 mm. Between the UL18V and NGK's, the other difference is heat range. The NGK's are hotter plugs compare to the UL18V, heat range of 12 for the NGK vs. 18.

If you have the clear fuel filter between the fuel pump outlet and the carbs' inlet and you are losing prime, i.e. carbs' bowl draining back into the filter, that means you either have a leak or the fuel filter is not oriented correctly.

I installed mine in a semi-vertical position (closer to the pump outlet) with the inlet side a little higher than the outlet side. This makes sure the fuel in the filter provides a "liquid" seal. Besides during normal operation the clear fuel filter almost always stays full an indication the fuel pump is working accordingly.

 

[slx12001]

Been starting great after 1-2 tries usually. Must have been a combination of whatever I did. lol

Also in my origional post I mentioned the engine smoked a lot. I would like to add that this was on startup. After running smoke was normal. The cheep pennzoil xlf really helped the starting smoke after a few tanks through.

 

[Jiggz]

I have exactly the same motor. You ought to try the NGK's BUHW. It's well worth the $12~$15 cost.

 

[slx12001]

My concern with the ngk plugs are my prestolite ignition being weak to start with. Also you state a 12 heat range for the ngk. That would be a very cold plug as the ngk's heat range go down as number goes up. 12 is almost off the chart cold. But I guess the ul18v is the coldest plug in the range as well. An L76v would be 1 warmer then the ul18v then in the surface gap I guess for champion.

COLD UL18V/UL77V+**

 

[Jiggz]

Oh well. I was running on UL18V for almost two years until I tried the BUHW and was overly impressed with the idle and WOT speed. But I guess it's just me. But isn't Champion heat range of 18 almost off the chart from being too hot?

 

[slx12001]

Champion heat ranges are goofy they actually go up to 99 or higher. It depends on the type of plug. It generally goes:

1-25 for auto and small engines
25-50 for aviation
51-75 for high performance
75-99 for special applications

So the ul18v is only 1 cooler than the L76v as the L76v is at the start of that range of plugs. Confusing right.

You can see the complete champion breakdown at the link below

 

[Jiggz]

Unfortunately, there is no so called standard heat range. What maybe considered to be hot by one manufacturer maybe considered cold by another. Like I said, I have exactly the same engine, 89-125HP with Prestolite Ignition, and have tried both NGK and Champions. And I personally prefer the NGK's. There is a heat range conversion chart floating around which indicates the Champions (UL18V or L76V) to be hotter than the BUHW or BUHX. Like I said, it's a personal preference. If you like the way Champion runs on your motor you should be fine. Both types are recommended by the maintenance manual.

 

[slx12001]

Unfortunately, there is no so called standard heat range. What maybe considered to be hot by one manufacturer maybe considered cold by another. Like I said, I have exactly the same engine, 89-125HP with Prestolite Ignition, and have tried both NGK and Champions. And I personally prefer the NGK's. There is a heat range conversion chart floating around which indicates the Champions (UL18V or L76V) to be hotter than the BUHW or BUHX. Like I said, it's a personal preference. If you like the way Champion runs on your motor you should be fine. Both types are recommended by the maintenance manual.

I agree run what you can get easily. A side note I believe that I read an article that stated that surface gap plugs should last nearly the lifetime of the engine or at least 500 hours. Wow

 

[Jiggz]

Surface gaps are only good as long as the gap is not fouled to the point that a spark is shorted and not creating a spark no more. Others still think spark plugs can be kept for a lifetime as long as you clean them but the fact of the matter, it does not. I've seen spark plugs actually had the electrode melt away. At less than $4 a piece, I do not understand why people would rather spent hours or even days trying to save old spark plugs. I guess it's just me . . . I don't mind spending less than $20 to eliminate one source of a problem or I think is a source of problem. I guess it's just me or maybe it's what boating is all about . . . $$$ down the drain.

 

[slx12001]

Surface gaps are only good as long as the gap is not fouled to the point that a spark is shorted and not creating a spark no more. Others still think spark plugs can be kept for a lifetime as long as you clean them but the fact of the matter, it does not. I've seen spark plugs actually had the electrode melt away. At less than $4 a piece, I do not understand why people would rather spent hours or even days trying to save old spark plugs. I guess it's just me . . . I don't mind spending less than $20 to eliminate one source of a problem or I think is a source of problem. I guess it's just me or maybe it's what boating is all about . . . $$$ down the drain.

I agree I generally put new plugs in my snowmobiles and most of my outboards yearly. Cheap piece of mind.