Engine has a miss after idoling.

[nikon4u]

So I am sitting at the lake with the engine running and waiting for my wife to get to the boat from the bathroom and then we go through the no wake area and then try to get up to speed. But the engine has a few misses. So I stop the engine and try again. Same thing. So I start it again and just try going slow, and she still has an occasional miss, but keeps going. I speed up a little and it seems to get gradually better, until it seems all cleared up. Now she is back to her normal self. Later on that day, I have a beginner skiier, which means a lot of idol and turning around and basically going slow. When the skiier finally got up and the boat needed to get up to a good speed, it missed again, and had to drop the skiier in the water even before she got to the hard water. Very dissapointing!:'(

Can anyone help me trouble shoot this problem? Keep in mind that the boat is in the back yard and not in the water. I do have one of thoes water muffs, but I don't know how long I can use that for.

 

[ctrlaltdl]

Re: Engine has a miss after idoling.

Read your plugs and see what they are telling you. You may need to adjust your idle mixture (assuming you have a carb).

Or just try changing your plugs. When is the last time it has had a tune-up?

 

[nikon4u]

Re: Engine has a miss after idoling.

I bought the boat less than a month ago, so I don't know about the tune-up.

I forgot to mention that it is a Mercruser 470 in a 1988 Caravelle.

 

[searay3]

Re: Engine has a miss after idoling.

need more info....year make s/n, at least what make of motor/drive and what type of fuel delivery, carb, injection?? Impossible to start troubleshooting with the info given...

 

[nikon4u]

Re: Engine has a miss after idoling.

is that enough info to help?

 

[searay3]

Re: Engine has a miss after idoling.

Start with a complete tune-up. Plugs/cap/rotor. replace the coil if you don't know the age of it. Fuel filters, water seperator if you have one. Post back after the tuneup. Could be a carb flooding issue, but start with the basics. A lot of ignotion symptoms mask themselves as fuel delivery. Have to be able to rule out the ignition as the problem.

 

[nikon4u]

Re: Engine has a miss after idoling.

I don't have a lot of cash on hand to do all that stuff if it isn't needed. Is there something that gives a clue to what the problem is so that I can start there first? Or has anyone ever had a problem like this before?

What could cause an occasional miss after a period of idleing or low RPMs?

 

[Don S]

Re: Engine has a miss after idoling.

I hate to be the one to tell you this, but if you can't afford a tuneup, and the standard preventive maintenance type items, including fuel filters, oil changes, points, condenser, cap, rotor, and setting things to specs, then you can't afford to have a boat.

 

[nikon4u]

Re: Engine has a miss after idoling.

Sorry for taking up your time, I'll try to get help elswhere. I suppose you all have always had plenty of money and you don't understand that I am just trying to have a good time on the lake on a limited budget.

 

[thunderroad]

Re: Engine has a miss after idoling.

nikon....some people here might have enough money to just pay for everything as the need arises, but I assure you, some of us don't.
If you're still here......most of the ignition parts are pretty cheap. A set of plugs will set you back about $25 and points/condenser $5-6. You didn't mention whether or not you had mechanical experience but even if you don't, I'm sure you know someone who could help out or give you some pointers. I'm far from a tech but a lot of the basics I learned back in high school foolin around with whatever car I had at the time still apply to workin on my boat.
Blue Springs, huh? Where do you boat, Lake Jacomo or do you go on down to south Mo? I'm just down the road in Marshall, Mo. Shoot me an email if I can help.
thunderroad@cdsinet.net
Stick around iboats. It's a very informative place.....even if some people do seem to get up on the wrong side of the bed from time to time.

 

[nikon4u]

Re: Engine has a miss after idoling.

Thanks Thunder, I think that I'm going to go out and tinker a little and see how I do. I usually put in at Blue Springs Lake. It's a big enough lake to do everything in and close to family and friends.

How far is Marshal from Blue Springs or Raytown?

 

[marunr]

Re: Engine has a miss after idoling.

If you already know this don't be offended...hook up the muffs and turn on the water before you even start cranking the engine. You can idle it and rev it up (within reason) on the muffs but don't run it at extended high rpm's.

The first thing you should do before trying to start it is dump the water seperating filter contents in to a clear glass so you can see if there is any water in there. You can probably buy a new one at Wal-mart (cheap)...replace it. If there's water in there you'll have to determine whether you need to drain the tank.

Next you can take off the flame arrestor and look down the top of the carb while you operate the throttle. You should see a steady stream of gas shoot in. Even if you do, the accelerator pump could still be defective or set wrong, but if you don't you need a new one.

Anyway, this is a cheap way to start out, but you will still probably need the full tune-up, ...and get used to it. You need to do the tune-up every year. It's really rare to go through a season and then winterize without spending $50 to $100 on just the basic maintenance of a boat. (That's if you do it yourself!)

 

[thunderroad]

Re: Engine has a miss after idoling.

nikon...Marshall is about 60 miles east of Blue Springs, just north of I-70 about 10 miles. We boat on the Missouri river at Waverly and Miami and occasionally the Lake of the Ozarks....waaaay down past all the crazy stuff.
marunr is right...expect to do a tune-up every year. Maybe it's weird but, to me, tinkering around on the boat is a big part of the fun. All my other hobbies got too painful. I'm not too up on the Mercruiser models...I assume a 470 is a 4 cyl GM, right? It should be easy to work on then.
No more than 4 plugs would cost, I'd jerk them out and put in a fresh set. Couldn't hurt...especially with the price of gas. Be sure and set the gap. You can pick up a gauge at Auto Zone or O'Reilly for a couple of bucks if you don't have one.
Let us know what you find. You mentioned it first happened after you idled while waiting for your wife to go to the bathroom so that means at least a half hour...long enough to foul the plugs d

 

[searay3]

Re: Engine has a miss after idoling.

You can remove the distrib cap and take a look inside. Take a small piece of emory cloth or sandpaper and clean up the contacts. Also clean the rotor tip the same way. You'll probably see some green stuff or at least pits from arcing. When done, use a mild solvent like Super Clean to wipe out the inside of the cap.The points you'll just have to replace, but that year, you may have electronic and it won't have points. Plugs you can pull and use a wire brush deep down inside the plug to clear whatever carbon you can. Filters and points simply have to be purchased. This may or may not resolve your issue. if it does, it probably won't last long but it will give you some time. If the boat is used on big water or for a living, this is not the way to maintain it.

 

[nikon4u]

Re: Engine has a miss after idoling.

Finally, some good help...thanks8)

What is, where is, and what is a water separating filter connected to? The other stuff I can find and tackle.

 

[searay3]

Re: Engine has a miss after idoling.

Water seperator is on the fuel line between the tank and fuel pump. Depending on the make, it probably has a spin on, looks like an oil filter. If you have one, before you pitch the old one, pour it's contents into a glass jar and look for water or goo at the bottom of the jar. this will give you an idea of whats splashing around in the tank. Next item would be the carb, but without a soaking and a kit, won't do any good and probably make things worse if you remove it and/or disassemble it.

 

[tystick]

Re: Engine has a miss after idoling.

see..... your in good hands here at the HMS forum help.
Even if ya do not have the extra coin, we can still work with it. It may not be text book but just might keep you running
Actually, the "rough around the edges" crowd have a wealth of knowledge so just have a thick skin.

There are alot of boaters here that try and be as thrifty as possible - but there is a limit to that as well

 

[Don S]

BEEN HERE BEFORE!

BEEN HERE BEFORE!

You can say what you want, I never said he should pay a mechanic to get his engine checked out. I only made my comment after he stated he couldn't afford the parts to do a tuneup and fuel filter change an a 4 cylinder engine.
He is not going out on a lake where WHEN the engine quits running he can just walk home, nope, someone is going to have to take time out of their leasure time to tow is sorry butt back to the dock so he can go home and sand paper his points again.

 

[DHPMARINE]

Re: Engine has a miss after idoling.

I don't speak for any one here but myself. But I do respect other posters.

nikon4u ....... sit back read and learn.

you also owe someone an apolgy

 

[nikon4u]

Re: Engine has a miss after idoling.

Well I changed the plugs and sanded the bug and cap, adjusted the timing, air & fuel mixture screws, and idle screw. She seems to be running better now. I didn't peek at the separater or mess with the points. The points look like they were changed in the spring, and I didn't do the separater because it is like 101 degrees out there!

Now I just need to get her out on the lake on Sat. to test it out.

Thanks for all the help.