3.0L sputtering and won't go over 2k rpms

[osfd401]

https://youtu.be/qxpm2U7Co7s

I believe I was able to get video uploaded. Carb was torn down, soaked in carb cleaner, washed out, blown out with can of compressed air, and reassembled. I don't have access to an ultrasonic cleaner. I can tear down and clean with tiny wire though. Thank you for the help Dodge!!

 

[alldodge]

At the beginning of the vid the motor appears to be idling above 1000 rpm's? The pic below was a snap shot after that time, but still looked like it was above 1k rpm.

In the pic below the trim looks like the drive is full up, is this correct?

I would do a compression test, the engine appears to be missing, but could also be an issue with the drive full up if this is correct.
Last note: increasing rpm above 2 and 3K rpms could have burned the impeller up on muffs. It should never be brought above 1300 rpm on muffs.

If the motor will idle between 600 and 700 rpm, then the idle circuits are clean and do not to have a wire run through them

 

[osfd401]

Yes the trim was full up. This is only the second time I have ran boat on muffs. Under load (in water) it does the same but not even go above 2k due to cut out. Motor will idle around 700. Compression test was performed before 150-155 on all cylinders. Mechanic also done compression test and said 180 across.

Impeller was replaced when I bought boat.

I am new to boats but I am a pretty handy car mechanic. I think I have an older video when on water. I'll try to upload it also. Thank you again

 

[osfd401]

https://youtu.be/MPJSUjSGbW0

Sorry for the video quality. This shows cruising at 1800 as running well and then 2k going crazy. Like I said sorry for quality. Hard to video and drive down the lake lol.

 

[alldodge]

Mechanic also done compression test and said 180 across.

Need to get rid of the mechanic, because that is way to high and if he actually got that reading and didn't think something was wrong he's an idiot .

What does the cap and rotor look like?
Where you able to get the motor timed?

I would suggest removing the drive, connect the hose to the thermostat housing and run the motor to see if things get better

 

[osfd401]

Replaced the cap and rotor twice. Same issues. Motor is in time. And what would removing the drive accomplish?? Are you meaning the upper drive or what exactly??

The first time I took boat out it ran a little better. Went to turn around and that's when it started acting like this. I drained the drive oil and it was mostly water. Later i diagnosed it as a leaking seal behind the prop. Properly replaced and filled with drive oil. So you might be on to something.

 

[alldodge]

. And what would removing the drive accomplish?? Are you meaning the upper drive or what exactly??
. I drained the drive oil and it was mostly water.

My original thought was to remove the drive because it may be the drive causing the issue, and after seeing the drive had water in it, then even more so. Run the motor to see if the issue clears up

 

[osfd401]

Dodge thank you so much for helping me out. I also noticed the other day the rear of the boat has a very distinct black line, kinda like it's burning oil. I don't feel comfortable pulling the drive myself but I will be getting with somebody and trying to get that done. Thank you again

 

[osfd401]

No Title

 

[alldodge]

Help is always good, but the drive is pretty easy to remove, just a little heavy. The stickys at the top of this section has instructions and how-to's

 

[osfd401]

Making progress. Removed the outdrive today. Hooked up water hose and same issue. Ran it to the point of "popping" and removed spark plug wires one by one. Number 4 cylinder is the one causing the issue. Removed the valve cover and investigated and the far back valve is not working. Marked the push rod and it is not moving any.
Tomm I plan on pulling that lifter. Hopefully I just hav a collapsed/bad lifter and not a wore out cam.
Does anybody know the part number for a lifter? And also will a auto lifter work, and if so which one?
Thanks again

 

[alldodge]

Marked the push rod and it is not moving any

Before you pull it apart it would be interesting to see what the compression is on that cylinder.

For the lifter, search for "Mercruiser 3.0 lifter" and several will come up, just find your year. It will be easier then looking for VP 3.0

 

[osfd401]

I did a compression check on July 9th and cylinder 4 was 150. I am assuming this valve is closed therefore it would build compression.

 

[RCSConstruction]

Need to get rid of the mechanic, because that is way to high and if he actually got that reading and didn't think something was wrong he's an idiot .

I don't mean to hijack but just quick question.
Is that for the 3.0 only? My 4.3 is 180 on all cyl's and I thought that was spec?

 

[alldodge]

I don't mean to hijack but just quick question.
Is that for the 3.0 only? My 4.3 is 180 on all cyl's and I thought that was spec?

The 4.3 spec is 180, the 3.0 is 150, along with 305, 350, 454 and 502

Here is manual 13 and 26, note 26 shows minimum but compression ratio is the same

My idot comment was out of line though, should restrain my self better

 

[osfd401]

Well I think I have some bad news. Pulled the lifter today and it doesn't appear bad. Put the lifter back in and rolled the motor over while somebody held finger on lifter and it never raised. Does it sound like a cam lost a lobe? Where is the best place or brand for a cam and lifter set?? Thanks again

 

[alldodge]

Don't know the best place, but I would just search for GM 3.0 cam and lifters and compare, maybe someone else has more info. With the lobe wearing out has there been any oil pressure problems?

 

[osfd401]

I do not know the history on the motor. Just going by what I was told and you know how that goes.

 

[osfd401]

To sum up my issue, the camshaft was worn. The #4 exhaust lobe was gone and most other lobes were worn down some. Replaced and done proper break in for cam. New lifters also. Motor sounds good and strong now. But now I am on to other big problems.
Took boat to lake to test out, reversed off trailer now problem, put in forward and turned around in the cove to point at dock better. Went to neutral, heard a little noise of nothing major. Turned off, parked truck walked back down, kicked off started up and had no forward or reverse. Long story short the vertical shaft is now sticking 2in above my outdrive. Busted a good size hole in bearing cover. What could have caused my vertical shaft to come undone and do this??

 

[alldodge]

The VP drives are out of my league, suggest posting new thread asking the question.