3.0 bogging at 3000 RPM (WITH VIDEO'S)

[snowman51789]

I have a 92 3.0lx mercruiser with a alpha 1 outdrive. the problem is when i get out on the water and go to take off the motor runs perfectly normal untill it hits 3000-3200 rpm. then it starts sputtering and dosent want to go any faster. after about 5-10 mins the engine will spring to life and the problem is gone untill i shut it down and it sets for more then 20 mins. ive replace the cap, rotor, new plugs and wires at the end of last year, replaced all fuel filters, and cleaned the carb. some body told me to spray starting fluid in the carb when it was sputtering and if it took off it would be a fuel issue and if it didnt its electrical, and it did not take off so im assuming its electrical

in this video you can hear it try to take off a few time from 20 to 40 seconds. (im feathering the throttle the whole time trying to baby it up to speed)

http://youtu.be/1ZkAaGeAgq4


after i stopped recording i took off so i stopped, let it cool for a few mins and tried it again. it bogs for a little bit then takes off, this was after about 10 mins of running. after it stops bogging the boat runs like nothing is wrong

http://youtu.be/SDztmhakvzE

 

[Rocky_Road]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

Here is Mercruiser's bulletin about 'bogging'. It may not be your issue, but it is common enough for the manufacturer to address:

 

[snowman51789]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

yeah my problem is when im already cruising not on acceleration. plus i rebuilt the carb. but thanks anyway

 

[snowman51789]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

Anybody?

 

[snowman51789]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

while I was out and it was sputtering at 3000 for about 8 mins I turned off my dash lights and then the motor would start to clime to 3200 rpm and when I turned them back on it would go back down to 3000. I did this about 3 times the the motor cleared up. This did not work when I first took off, the lights had no affect. The closer it got to clearing up the more the affect of flipping the lights on an off had.

Any thoughts?

 

[Rocky_Road]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

while I was out and it was sputtering at 3000 for about 8 mins I turned off my dash lights and then the motor would start to clime to 3200 rpm and when I turned them back on it would go back down to 3000. I did this about 3 times the the motor cleared up. This did not work when I first took off, the lights had no affect. The closer it got to clearing up the more the affect of flipping the lights on an off had.

Any thoughts?

Funky alternator?

Check your belt tension...a loose belt will reduce your alternator output.

 

[CAPTKEV85]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

while I was out and it was sputtering at 3000 for about 8 mins I turned off my dash lights and then the motor would start to clime to 3200 rpm and when I turned them back on it would go back down to 3000. I did this about 3 times the the motor cleared up. This did not work when I first took off, the lights had no affect. The closer it got to clearing up the more the affect of flipping the lights on an off had.

Any thoughts?

did you replace any lights in gauges, dash, any lights? Maybe you have wrong bulb or grounding issue with lights. I once replaced a bulb in my tachometer and the boat wouldnt go over 3000 rpms I pulled the bulb and the boat took off.

 

[Peaceful Pirate]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

snowman - It may not be of any help, but we had a similar problem. We finally found the problem was the ballast resistor!

http://forums.iboats.com/showthread.php?t=493923

 

[picklenjim]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

In the video it sure didn't sound like that engine was turning 3000 rpm's. The tach looked like it went to 3000 almost instantly. Sounds like you might be on it pirate. I don't even know why they run those resisters.

 

[snowman51789]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

ok time for an update, last year somebody told me to hook the coil up directly to the battery, if all was good then it ment i had a short in the wiring, when i hooked the coil to the battery it ran great. so i ran a new wire back to the coil and everything was great untill the end of last year, then the problem started again, but this time it was at 4000 rpm, it was late in the season so i just winterized the boat and let it go, this year i got the boat out and the problem was back, the first time i had it out i hooked the coil back up to the battery and it went away, today i took the boat out and today when i hooked the coil to the battery it was bogging at 3000 rpm.

i bought a new boat and i realy need to fix this one, im not willing to sell the boat when its not in good working order, however i do need to get it sold because i need the money from it.

any addvise would be great

thanks

Dave

 

[90stingray]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

Have you looked into any of the above suggestions? Like the alternator output, ballast resistor, etc... Heck if you gotta sell her, just price it accordingly and send it down the road.

 

[snowman51789]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

the only way i know of testing the alternator output is by checking the voltage while its running, yes i did that and it was good, around 13 volts if i remember corectly,

correct me if im wrong but the link about the ballast implied that if the ballast resistor was bad, then the tach would do funky stuff to?? my tach is working good.

 

[mpdive]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

I am not convinced that it's not fuel related. The starting fluid is viable only if caught before the tipping point of staying running. I would still run it off a can just to eliminate the primary fuel system components (filter, anti siphon valve, etc.). Since your problem is not sporadic, testing the fuel sysyem gives you the opportunity to rule out fuel and move on. I have seen anti siphon valves duplicate your problem. Just a thought.

 

[snowman51789]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

i have worked on many small motors, (ie. dirt bike, snowmobiles, atvs) i have used the starting fluid many times so unless a boat motor is different im pretty sure i did it right, i did replace the anti siphon last year with no luck, and so be sure that the carb was getting enought fuel, i installed a petcock between the fuel pump and the carb, when i was running on a plane i shut the petcock, when i did the boat ran for about 15 seconds or so (untill the motor used up the fuel in the bowl of the carb) and then the motor started to sputter and die, plus like i said, when i hooked the coil to the battery the boat ran good, if it was fuel i wouldnt think that would happen. like i said i only have experance on small motors so if any of that was wrong please correct me.

 

[mpdive]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

i have worked on many small motors, (ie. dirt bike, snowmobiles, atvs) i have used the starting fluid many times so unless a boat motor is different im pretty sure i did it right, i did replace the anti siphon last year with no luck, and so be sure that the carb was getting enought fuel, i installed a petcock between the fuel pump and the carb, when i was running on a plane i shut the petcock, when i did the boat ran for about 15 seconds or so (untill the motor used up the fuel in the bowl of the carb) and then the motor started to sputter and die, plus like i said, when i hooked the coil to the battery the boat ran good, if it was fuel i wouldnt think that would happen. like i said i only have experance on small motors so if any of that was wrong please correct me.

I would say then that you could rule out the fuel issue, but when you closed the petcock, was this at a time you were having the bogging issue or when it was running fine? Fuel pump diaphrams fail sporadically too. I can see where you want to lean against a fuel issue and I would probably feel the same way. As far as the coil goes, any past problems with a bad plug wire or plug that could have caused the start of insulation shorting in the coil itself?

 

[Don S]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

The need to use starting fluid on anything, means one thing only. There is a problem somewhere with that engine, or you wouldn't need it.

You don't see a new anything coming with a can of starting fluid so you can get it started do you??????

 

[snowman51789]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

Don S i dont realy understand what your asking??

Im thinking that today after work im going to get a new coil and try it, i just have a hard time spending the money because everything that i have read about coils going bad says that they act fine when the engine is cold and they start acting up when the motor gets hot. for me its the oposite. it bogs for about 10-15 mins while under power (actaul engine temp dosent seem to matter) then it clears up and runs great untill the boat sits for about 30-60 mins. but there is much else to try and i realy need to sell it. i screwed up and was hoping id be able to fix this problem fast when i boat my "new to me" boat. but you live and you learn i guess.

 

[mpdive]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

I would agree with swapping out the coil. Can't hurt. Your doing the right thing by trying to sell it intact. If it persists, I would take the potential buyer on a sea trial if possible, and show him what it's doing. I personally would not be turned off by this if I was a potential buyer, but might only ask for a little off the price to help with some part's replacement. Most men are "tinkerer's and like a challenge if the price is right. Keep us posted on your progress and good luck. Last but not least, are you sure the choke is not staying wide open or the choke coil tension is not extremely loose. It sure would give you cold driveability problems......

 

[coopin87]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

yeah my problem is when im already cruising not on acceleration. plus i rebuilt the carb. but thanks anyway

Just curious. How experianced are you with rebuilding carbs? If memory serves me right the rebuild kits dont come with new floats (correct me if im wrong) Still sounds like a fuel issue (like something is restricting the flow temporarily). Just a thought.

 

[snowman51789]

Re: 3.0 bogging at 3000 RPM (WITH VIDEO'S)

I checked the choke last year and all was good. I rebuilt the carb last year also. This was by first automotive or boat style but I've rebuilt at least 50 snowmobile. Or dirt bike carbs