HESITATION

[U68423]

1989 FORCE 125 motor has a hesitation at WOT somtimes seems like it was not getting fuel, as the hesitation happend a friend of mine pumped the primer ball but nothing changed. Seems the only way to fix it is to power down and then power up again sometimes that cures it. To add it seems to happen more after travaling at low speeds, at half throttle it runs fine all day, only at wot this happens. I have replaced the diaphram, de-carb at the begining of the season. New plugs but ad I stated in previous posts I do run my idle screw setting 3-4 turns out from seated. The feeling is like getting some bad gas.

 

[The Marine Doctor]

Re: HESITATION

I think if you find out the problem of why you have the low speed needles turned out 2x farther than they should be...you will solve all your problems.<br /><br />Has anyone changed the carbs? Check the numbers on them and compare them to OEM.<br /><br />TMD

 

[U68423]

Re: HESITATION

Ok I will try to re-adjust the carb settings. When I got the boat it ran fine I only looked into the settings and the fuel pump because I could not get the motor to start once I put it in the lake, that was my fault I had no clue about the fast idle setting or how to engage it. Anyway while poking around I noticed one screw missing on the fuel pump and fuel coming out of the gasket, replaced gasket, diaphram, and screw. I also decarbed and noticed the idle screws were set out 7-8 turns. Question for The Marine Doctor was the setting so far out to compensate for the gasket leak ? And if so why did the motor run very well for the previous owner and during my test run with him ? I now can start the motor It runs very well at 800 - 3500 rpm, but it will not go higher then 4,200 fully trimed up, and then that hesitation or miss 50% of the time. I will pull my plugs clean them and set thr idle screws 2 turns out and see how she runs. Any advice is welcomeeee

 

[U68423]

Re: HESITATION

Ok I will try to re-adjust the carb settings. When I got the boat it ran fine I only looked into the settings and the fuel pump because I could not get the motor to start once I put it in the lake, that was my fault I had no clue about the fast idle setting or how to engage it. Anyway while poking around I noticed one screw missing on the fuel pump and fuel coming out of the gasket, replaced gasket, diaphram, and screw. I also decarbed and noticed the idle screws were set out 7-8 turns. Question for The Marine Doctor was the setting so far out to compensate for the gasket leak ? And if so why did the motor run very well for the previous owner and during my test run with him ? I now can start the motor It runs very well at 800 - 3500 rpm, but it will not go higher then 4,200 fully trimed up, and then that hesitation or miss 50% of the time. I will pull my plugs clean them and set thr idle screws 2 turns out and see how she runs. Any advice is welcomeeee

 

[The Marine Doctor]

Re: HESITATION

That is quite possible as you would have had a lean problem. By turning the idle screws out you were giving the engine more gas.<br /><br />Keep in mind that you had to do this with BOTH carbs. I think that is the key here.<br /><br />TMD

 

[U68423]

Re: HESITATION

Exactly, and I bet if it is not ignition related that the hesitation will go away once I adjust the idle screws to a more lean setting. Marine Doctor, do you think that my WOT may also increase? The boat is a 19' Bayliner Capri Bow rider, as it sits now it will do 35 - 37 at 4200 rpm, stock prop, not sure about the pitch. Also I am going to change the prop next season this prop has nicks on all 3 blades.

 

[U68423]

Re: HESITATION

Exactly, and I bet if it is not ignition related that the hesitation will go away once I adjust the idle screws to a more lean setting. Marine Doctor, do you think that my WOT may also increase? The boat is a 19' Bayliner Capri Bow rider, as it sits now it will do 35 - 37 at 4200 rpm, stock prop, not sure about the pitch. Also I am going to change the prop next season this prop has nicks on all 3 blades.

 

[The Marine Doctor]

Re: HESITATION

I cannot comment on whether you will get more speed or not. There are too many variables to consider.<br /><br />Hopefully though it does pick up.<br /><br />Also try spraying some engine tuner around the crank halves. If the idle increases there is an air leak in that area and will need to be resealed.<br /><br />Any kind of air leak requires additional fuel.<br /><br />As for the prop...you might just get yours rebuilt.<br /><br />TMD

 

[tteal]

Re: HESITATION

U68423,<br /> If it makes you feel any better, I have the same issue (have been reading your issues and have the same thing with the a/f mixture screws and also the hesitation).<br /><br /> I have done a ton of work on my race car and although I don't know much about the outboards, from what I've gathered it appears that you might be running far too rich. <br /><br /> If you end up finding a solution to this hesitation issue that you're having (described in your post here), I'd love to know if/when you correct it and how you did because it just might help me as well.<br /><br />Good luck,<br /> Tim

 

[ezy33]

Re: HESITATION

I had the same kind of a problem on my 85 hp force, when I pulled the plugs one was clean. Compression was low in that cylinder. Replaced head gasket and machined head. That's my 2 cents. Good luck!

 

[U68423]

Re: HESITATION

Doc where are the crank halves ? engine tuner ? Is that like carb cleaner? My compression is fine 125 -130 all cylinders. Tim if I figure it out I will post the cure, thank the Marine God's for all the people on this board who give great advice. I will try to do some work on her tonight.

 

[The Marine Doctor]

Re: HESITATION

This is where the front half of the block bolts together with the back half.<br /><br />TMD

 

[U68423]

Re: HESITATION

Well here it is, last night I did some work on the old girl it is amazing how straight forward all the work is. Had trouble starting the motor and then when it ran it would sort of sound like one or 2 cylinders were cutting out, that never happend before . Anyway I pulled the plugs, the top plug was very dirty (black) but easy to wipe off, the other plugs were much cleaner just a little black wiped right off. I the opend my first beer and put the plugs in adjusted the idle 1 turn from seated and started her up did the adjustment as per the book and ended up at 1 1/2 out from seated for both carbs. Now the real test I ran her on the lake and to my suprize the miss or hesitation at WOT was gone ran her for 15 min at 4600 and 42 mph. Seems like it is solved any comments on what might have been wrong is welcome, I think if it happens again it has to be ignition related. Almost forgot I think the top carb needs some work everytime I shut her off a small amouint of fuel spills out? Marine Doctor what are your thoughts on this post and my engine?

 

[tteal]

Re: HESITATION

U68423,<br /> Glad to hear it's working out for you. One quick question and not to jump into your thread here but when you say you adjusted the idle one turn from seated. <br /><br />When you say "seated" what exactly is that? Does that mean that the air/fuel bolt is fully clockwise and you turned it counter-clockwise? Sorry for the silly question but I'm just trying to get mine running in tip top shape as well.<br /><br />Thanks,<br /> Tim

 

[The Marine Doctor]

Re: HESITATION

Well from what you say now...I would suspect that your problems might almost be gone.<br /><br />Do a little bit of work to the top carb. There should be no fuel leaking out at anytime.<br /><br />Idle must be quite smooth now...and I would think that you would have to idle it down a bit now as it would have picked up considerably once the correct amount of fuel was going through.<br /><br />Its possible that you were fouling the top plug with to much fuel going through at idle..coupled with the fuel that seems to run out.<br /><br />Just to QUOTE from the start of this post.<br /><br />I think if you find out the problem of why you have the low speed needles turned out 2x farther than they should be...you will solve all your problems. <br /><br /> <br /><br />What you might try next is a lower pitch prop to get the engine closer to its recommended RMP at WOT.<br /><br />You could probebly drop a pitch or 2 and still have good speed and plenty of power.<br /><br />TMD

 

[U68423]

Re: HESITATION

You are correct as usuall Doctor. I orderd the rebuild kit for the carbs also orderd the correct screws for the fuel pump, as I stated in my first post months ago I was missing a screw at the fuel pump and gas was leaking out when the primer ball was squezed, the screw that I got fits but is getting loose and I think that was also causing the problem with the hesitation and the idle screw setting, have lock washers but might have to add some lock tight. As for the prop it is in bad shape lot's of nicks, I will get one at the start of next season, I onlu use the boat 2 or 3 days a week. Tell you what that Tiny Tach works great.<br /><br />TTEAL, seated means clockwise until the idle screw can not turn in anymore, do not force it or tighten it just seat it then screw it out counter clockwise to the setting your manual recomends, for your motor I believe it's 1 1/4 hope that helps..

 

[U68423]

Re: HESITATION

^^^^^^^^^^^^^^^^^^^

 

[tteal]

Re: HESITATION

U68423,<br /> Thanks alot! That will help me get mine dialed in hopefully

 

[Forceluver]

Re: HESITATION

Hello all, just learned how to rebuild a 85 hp, trace and fix all electronics problems and now heading to the carbs. I have a top speed of 29 mph I'm guessing its with the mixture. I did not see the what I wanted to here, Someone please help me.<br /> From what I understand the book says to go 1/1-4 from seeted, I got that. But my motor Is bored 30 over. So when I turn the screw counter clockwise what am I looking for, Is the motor going to run rough? I do not want to go to far.

 

[The Marine Doctor]

Re: HESITATION

Forceluver...please start your own post as it will get more response that way <br /><br />TMD