2008 Mercruiser 4.3L Alpha One Performance Issues

[kwortman]

alldodge , how about a malfunctioning TKS module? I don't know enough about these to troubleshoot...Also op, did you adjust the idle mixture after the carb rebuild?

nola mike interesting that you asked this because I did notice when i took the TKS module off on Saturday that there was a small section on it that looked as though it was melted just a bit. Unfortunately the pictures of the TKS module I took as I was taking the carb apart doesn't show this or I would post. I didnt think much of it until your post. I am not a mechanic by any stretch of the imagination so I have no idea if this would be an issue or not.

 

[Furbird]

Whoops, it is supposed to be in the middle. So I guess which way is richer or leaner would be the better question. Sorry.

 

[kwortman]

Watched a youtube video and maybe the pump rod is in the wrong spot? It should have three holes and supposedly you're supposed to start in the hole closest to the carb. Mine hesitates some on my brand new carb and it was shipped in the middle position. Was actually going to post this anyway to verify this information but if both of us have a similar issue, kill two birds with one... thread?

https://youtu.be/6tLeTT4rNSI?t=213

So I put the pump rod back into the middle hole where it was. After watching mulitple carb rebuild videos for a mercarb everyone put back in the middle or said to put it in the middle. That is where it was before the rebuild and I was running to rich (according to my spark plugs)

 

[kwortman]

Whoops, it is supposed to be in the middle. So I guess which way is richer or leaner would be the better question. Sorry.

my understanding is the top hole makes it richer and the bottom hole makes it leaner. Middle is standard

 

[alldodge]

Correct, the holes can make it more rich or leave. That said this is for accelerating and don't look at plugs when doing the adjustment. The adjustment is done compared on how well the motor accelerates. If it bogs it may need more, not bogging but sort of sluggish then maybe a bit more lean

If the module is closing off the enrichment port and not blowing the fuse then for the most part its working. The manual for rebuild is 41 and is at boatinfo and list all adjsutments

http://boatinfo.no/lib/mercruiser/manuals/mercruiser41.html#/0

 

[kwortman]

The manual for rebuild is 41 and is at boatinfo and list all adjsutments

http://boatinfo.no/lib/mercruiser/ma...iser41.html#/0

You sent me this the other day (which I appreciate very much) and I think I did the adjustments (seat the idle mixture, turn 3 1/16 out, seat idle speed and turn 2), get boat up to temp, put in forward gear at idle, remove throttle cable and adjust idle mix then go back and check idle speed (650). My question is, is it possible that the idle mixture didn't get adjusted properly and I should reset back to initial and try again, would the idle mixture cause something like this to happen or could it be something else like fouled spark plugs, a fuel pump or a bad anti-syphon valve if I can find one on the gas line? I Did all these adjustments while trying to make sure I didnt hit anything as I was alone and perhaps didn't take my time like I should have

 

[alldodge]

Those idle adjustments are best done tied to the dock, but if you don't have a dock then do understand

If the plugs were a bit fowled then after adjustments are set correctly then the plugs will clean them selves up.

It could be the adjustment is not correct, but could also be the idle channels are not clean enough, or if adjustment screw was damaged during adjustment, this to can cause a rich mix

I think your close

 

[kwortman]

Those idle adjustments are best done tied to the dock, but if you don't have a dock then do understand

Okay now I feel really stupid. My boat is in a slip in the water. The slip is basically a floating dock with about 30+ other boats. How would I put the boat in forward gear (I assume forward at idle means in gear one click past neutral) and not run into or push the dock?

 

[Rick Stephens]

Okay now I feel really stupid. My boat is in a slip in the water. The slip is basically a floating dock with about 30+ other boats. How would I put the boat in forward gear (I assume forward at idle means in gear one click past neutral) and not run into or push the dock?

Your choice in this is either put in gear tied up to a dock and let it push against the dock, or, take someone with you and let it idle across the pond.

 

[alldodge]

I doubt if your boat idling will move the dock. My buddies 37 foot with twin 454's doesn't move out dock (slip) if he is idling.


If yours does, then maybe drop an anchor

 

[kwortman]

alldodge Rick Stephens thank you both. Never even occurred to me that you could do that. How much easier that would be and wouldn’t have to wait for the weekend.

 

[kwortman]

Disconnect the throttle linkage at the carb. Start the motor and let idle a minute. Turn OFF the motor and go and open the carb throttle plate and see if it starts to squirt fuel down the carb and does it from start to at least 3/4 open. Your looking for a steady stream

alldodge Yep I have a steady stream.

as for the idle mixture we were talking about further down in this thread Apparently when I was making my idle mixture adjustments I a. Screwed it too far in clockwise and mushroomed the tip and b. bent the screw so I’ve ordered a new one but here’s what’s happening to me. When i turn clockwise to begin the adjustment the screw goes all the way to seat. The engine never acts like its dying or dies when all the way seated is This right? If so how do I adjust just let it seat and then start counting the turns counter clockwise until the boat almost dies, split that difference and then turn back clockwise the split difference turns or is the newer idle mixture
screw not going to work in this carb? I think I bent it because I kept adjusting over and over thinking I was doing something wrong since the boat doesn’t act like its going to die when doing those initial turns clockwise

 

[alldodge]

The seat inside the carb has been damaged and doubt it can be fixed

Your getting a steady stream but still dying, need to start with the basics. Compression, timing and then back to the carb. If idle is getting to much fuel this will cause it to be rich, but will not cause it not to accelerate. If float adjustment is to high in can flood or to low then not enough fuel.

As Rick said, the main carb channels may not the cleaned

 

[Rick Stephens]

I hear the frustration. As AD said, you ned to start from basics. One thought I had with your description was the motor could do that if the ignition wasn't advancing. Not sure how an electronic ignition can work but not advance, but easy enough to check with a light. You should see well over 20 degree BTDC when your engine hits 2500 RPM. Even momentarily.

Maybe a load of bad fuel?

The list starts to get longish and you have to start crossing things off it.

 

[kwortman]

I hear the frustration.

Frustration yes but I also am learning a lot here and doing things I would have just paid a mechanic to do. I am spending money on tools and diagnostic equipment but next time I won't have to. I really appreciate your patience with me Rick Stephens and alldodge

Attached a pic of the inside of the carb. I took it back off yesterday, rechecked the float measurements and used compressed air on everything I could again. It looks prett good to me perhaps you have other thoughts?

Just discovered Harbor Freight and think this might be my new go to store. Timing light 30 vs. 65 or more on Amazon, 30 for a compression test kit and based on what I read in SELOC manual neither doesn't sound to hard to do either

 

[Rick Stephens]

Switch yourself over to the Mercruiser manual for what you are doing. Too often Seloc not only not getting the fine points but wrong in what they may tell you. For now, you can read online at www.boatinfo.no Eventually you'll find a download copy or purchase the real thing.

There are somethings Harbor Freight good at, others, not so much. Is still pretty much all chinese junk compared to a real tool. If not used often, many of that is good enough though.

 

[kwortman]

Switch yourself over to the Mercruiser manual for what you are doing.

so alldodge turned me on to this with my recent carb rebuild but I noticed the date is 1999. Still valid for a 2007/2008 boat?

 

[alldodge]

so alldodge turned me on to this with my recent carb rebuild but I noticed the date is 1999. Still valid for a 2007/2008 boat?

That is manual 25 which is at boatinfo and located in link

http://boatinfo.no/lib/mercruiser/manuals/mercruiser32.html#/0

Keep in mind there is a manual 32 which starts in 2001 but only deals with MPI motors

 

[kwortman]

Keep in mind there is a manual 32 which starts in 2001 but only deals with MPI motors

Yep I saw that not sure if I am an MPI Or not but same question applies since that manual is dated 2001. Now with that said, SM 41 worked like a champ so not sure what I am
worried about. I probably pay too much attention to detail

 

[nola mike]

You don't have an MPI (fuel injected) since I can see a picture of your carb above. Just bought a harbor freight timing light after my 20 something year old craftsman died last week. In addition to air, I'll spray carb cleaner in the passages after chasing them with some fishing line or strands from some copper wire