Weird problem with 1988 OMC 3.0

TwoBallScrewBall

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Hi all,<br /><br />this is my first boat and my first post here. Recently picked up a 1988 bayliner capri 1900 with an omc 3.0. Engine ran good for a while but now I have a strange problem. It seems like it is starving for fuel now. It has two personalities. When it's acting good, it idles perfect and had good throttle response and top end. But when it's acting bad, the idle is very rough and it will only spool up to around 1500 rpm. It is out of the water at this point. I am thinking that the carb needs a cleaning and maybe a rebuild, but wanted to run this by the board first since there seem to be so many knowledgable people here I figured I might save myself some time. I got home from work today and started it, it ran bad. Then I shut it down and checked the firing order, it was fine. Started it back up and it ran great for about 2 minutes, then went right back to the rough idle and no top end. Any ideas folks???<br /><br />Thanks!
 

TwoBallScrewBall

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Re: Weird problem with 1988 OMC 3.0

OK, second post. I just got back from messing with it some more. I noticec now that it is belching black smoke when I go to full throttle. So it's not starving like I thought, it is actually drowning in fuel. I think maybe a needle or float is stuck, and a carb rebuild is in order. Anyone have any other ideas or confirm my theory?
 

TwoBallScrewBall

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Re: Weird problem with 1988 OMC 3.0

Well I figured it out. My shift linkage needs to be adjusted, and I don't think that the ESA circuit is disengaging, thus limiting my rpm and roughening the idle. Time to order the clymer and RTFM! :) <br /><br />Well, thanks anyway!
 

rodbolt

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Re: Weird problem with 1988 OMC 3.0

hello<br /> does your shift block assy have one micro switch or 2. the second switch was for overstroke. the small amout of cable movement after the shift is done and the throttle is taking up. I see some overstroke switch failures from time to time. if no repairs have been done then be careful with the adjustments.<br />look for an overstroke swith and post again
 

TwoBallScrewBall

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Re: Weird problem with 1988 OMC 3.0

Yes there are two switches. One has a long arm on it and seems to be just for the range between neutral and the gears. The other just has a small button on it, this I'm guessing is the overstrok switch you're talking about. What does it do and what should I look for?<br /><br />Thanks!!
 

TwoBallScrewBall

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Re: Weird problem with 1988 OMC 3.0

It is also quite difficult to shift from neutral into either gear, and sometimes does not go right back into neutral.
 

TwoBallScrewBall

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Re: Weird problem with 1988 OMC 3.0

Well in case you were wondering, I resolved my problem. It was the overthrow switch. I sprayed some electrical contact cleaner on it and the boat runs like a champ again. I might pick up a spare switch just to keep handy in case it gives out completely on the water. Also, the outdrive was not all the way down, once I lowered the front of the trailer enough to drop the outdrive completely it got very easy to shift. Is this normal or should I look at the linkage over the winter?<br /><br />Thanks!
 

rodbolt

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Re: Weird problem with 1988 OMC 3.0

Hello<br /> the only time the shift switch is needed is to shift from any ingear position to neutral.omc had some concerns about the linkage triggering the esa due to cable movement after shifting.the overstroke switrh opens the circuit for the esa module onc any in gear position is reached and is the first swith to release when shifting back to neutral. the adjustment on them is critical and sometimes frustrating :) :) . as far as outdrive position it should not matter the drive orientation for shifting. I would suspect the cable is going bad at the bend from the transom shield assy.if the cable is black it should be replaced anyway. also a good time to check/replace ujoints and drive bellows.check gimbal bearing as well. the clymer manual is pretty straight fwd about cable replacement on this setup.<br /> good luck and keep us posted
 

TwoBallScrewBall

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Re: Weird problem with 1988 OMC 3.0

The cable is red so it was updated. I'm going to live with it for the rest of this year and just make sure I don't mess with the gear shifting if the outdrive is up in case it is further damaging the cable. This is my first boat and for an 88 bayliner it is in great shape, firm deck, no cracks, etc, but I do have a small list of winter projects going. I'll add the cable to the list. <br /><br />Thanks!!
 

TwoBallScrewBall

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Re: Weird problem with 1988 OMC 3.0

Also I don't have a manual yet but I was able to determine by obversation and manually manipulating the switches how it works. As I see it, the first switch causes the engine to misfire and stays engaged whenever the engine is not in neutral. The second switch (overstroke) just disables the first switch once you are far enough in gear. Correct?<br /><br />Thanks again for the help, nice to have a place like this to use as a sounding board of sorts.
 

Boatin Bob

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Re: Weird problem with 1988 OMC 3.0

Actually you are almost right, the interrupt switch (with the arm on it) should only activate while you are going in or out of gear, it should not stay active once the shift is complete, the arm should go back into the valley of the v dhaped notch. You are right about the other switch, the overstroke was put there to prevent the ESA circuit from activating once in gear, the newer ESA's don't use the overstroke anymore as they have a built in timer that cuts off the ESA after 5-6 secs. If your interrupt switch is staying activae after the shift you need to fix that, could be a lower shift cable adjustment, don't depend on the overstroke switch to cutoff the ESA
 

TwoBallScrewBall

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Re: Weird problem with 1988 OMC 3.0

OK. The ESA switch does not disengage, it remains engaged whenever the boat is not in neutral. The V shaped groove thing stays in position. I'll take a look at it more after work today. Thanks for the info!
 

rodbolt

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Re: Weird problem with 1988 OMC 3.0

Hello. if your lower cable is stiff then the shift interrupt swith may not work quite as designed. but some controls would overstroke and rather than fix all the controls OMC used the overstroke switch. so this winter its time to get busy and pull that drive and get some maintenance done :) <br /> keep us posted
 
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