VP 4.3 GL-B - Spark issue

[Mymarcec]

Yes, I'm going with DIY. My father was a mechanic and he hated it when I took something without a computer to a shop. I'll probably go buy a compression gauge to do that check as well. Right now I have more time than money, so I'll put some careful effort into it.

I bought the boat from my brother in law about 4 years ago, but haven't used it much. He used it in the ocean (I don't), and knowing what I know now, I should have avoided it. Oh well.

When it ran, it sounded like the gimbal bearing is going, so I think I'll save the shop $ for that job.

Thanks for the pep talk

 

[Lou C]

Another thing you need to look at if it was used in the ocean are the condition of the exhaust system & intake manifold. Boats such as these used in ocean salt water need to have the exhaust system inspected at regular intervals (usually being replaced @ 6-8 years) and the intake can rot out under the thermostat housing and that should be checked every 2-3 years or so. Not replacing the exhaust will eventually put water in the cyls and for the intake it will put water right into the cam valley & motor oil.

 

[ESGWheel]

Welcome to the dark side, I mean the fun side
I too was an (auto) mechanic – but that was decades ago and short term professionally prior to joining the US Navy followed by another career after that I am now winding down. But I never stopped working on my (and other’s) cars and still do most of my own work. That said I am still not set up for nor comfortable with pulling the sterndrive but am gearing up for it in the next couple of years. So, agree with leaving that sort of activity to the shop (at least for now).

One thing I did do was get every single OEM manual for the motor, sterndrive, etc. almost on day one of getting my current boat. They will come in handy over time, so suggest finding them and getting them now. Well worth it.

 

[Mymarcec]

Yes, manuals are very valuable.
I did the carb rebuild today but got a generic kit for the Holley 2 barrel carb, and it didn't have one specific part. In this video (not mine) at 6:02 is a red flapper relief valve or something:

The kit didn't come with one and the one in my carb looks like it's barely hanging on. I suspect to get that part I'll have to order a full kit from Volvo. I'm looking through this volvo parts website, and can't figure out which part number is that little thing. I assume it is something used to marinize the engine, but I don't know.
https://www.volvopenta.com/shop/0?categories=2/23&product=4.3GL-B&size=60
Any ideas what it is called, so I can maybe try ordering just that part? (haha).
Thanks!

 

[ESGWheel]

I think what you are referring to is the ‘check valve vent’ for the accelerator pump. For the accelerator pump to work it needs to move back and forth similar to a piston in a cylinder. One side is the fuel, the other is the atmosphere and without the ability to ‘vent’ it does not work. The little red flapper is controlling that venting.

There are others on this forum that can help guide to the ‘full rebuild kit’ from aftermarket, ie, I do not think you need to get a VP rebuild kit (if even available) but rather a Holley aftermarket one.

Also: did you do the ‘tests’ like mentioned in post 20? And did the rebuild kit come with a new needle / seat & float? Sometimes only needle and seat and no float > if so, need to check that the float actually floats if you do not have a new one.

And there is a process to set the ‘float level’. This is again akin to the toilet analogy. Too high and you get flooding. Too low and do not get a proper flush (fuel starvation). The kit should come with a gauge and instructions on how to.

 

[Mymarcec]

Haven't checked compression yet, tomorrow's job.
Kit had new needle/seat - no float. This float looks good and floats in water.
I leveled the float as per the instructions in the kit, it sits level (parallel to the bottom) when dry. I found another after market kit that includes the valve vent, so ordered that.

 

[Mymarcec]

Got to the boat this morning. Pulled all the plugs, they were all wet (gas). However, tweaked my back doing that (getting old sucks...) so only put the compression tester on one (front passenger) and only finger tight, tested at 90psi. Seems a little low, but was only finger tight. Now I need to get my back straightened up

 

[Mymarcec]

Went back today. Compression tested 120-140 (120-125 at the front, higher at the back). A little wide in the range, but should run that way I think. Maybe need some engine work soon. I took the thermostat out and it was pretty clean, no major issues that I could see. New carb kit (for that missing valve) should arrive today so hopefully can get it back together and see if she runs soon.

 

[ESGWheel]

Agree your compression is fine to run. So now you know you have 2 of the 3 needed ingredients. Spark and Compression. And while you have fuel, you have too much of it as evidenced by the wet plugs and the other symptoms your id'ed. Finish that carb rebuild and get ready for some boating action!

 

[Mymarcec]

Still no luck and too much fuel...

Installed the carb, still too much fuel. Although I've learned that the rebuild probably did some good as previously fuel was flowing from the "J pipe" (referenced in another video I found). Now it is flowing from two spots in the carb directly into the barrels, one each. The fuel flows strongly for about 10-15 seconds after I turn the key off from cranking - I assume it flows while I crank as well, but I can't see it. This is way too much.

So I take the carb off again, pull it apart - still lots of fuel in the bowl even though so much flowed into the barrels, check the float assembly very closely. Recheck that the float does indeed float in water. Reassemble carefully to make sure float can close the seat and reinstall. Same issue. Way too much fuel.

Looking at the fuel pump that I ordered using the Volvo part number (3858261), but this is an after market pump. The Amazon listing says low pressure in one place and high pressure in another. Should a GL-B 4.3 carb engine have a high pressure pump? If it is a high pressure pump, could that be causing the excess fuel issue that I have? I can't find a definitive answer yet.

I have been through the carb twice now and I don't see any physical problem with it. I can blow carb cleaner through all the little openings and it seems to come out somewhere else so no blockages.

Pump? or carb? or user?
Thanks.

 

[ESGWheel]

Not user. The pump you listed appears to be correct. But you are also correct thinking if the pressure is too high it can unseat the needle in the carb, causing flooding.

Do you have a way to measure the PSI of the pump output? Others will know the exact spec but should be in the range of 5 to 7 PSI.

Other thoughts:

• Is the float a soldered-up hollow type? I know you said it floats but if a hollow type, shake it and see if any liquid inside > should not be. If the ‘solid’ black plastic type, while I have not experienced it before maybe it can still be bad due to saturation of gas or water, ie will still float but not as much as it should. If this type did the float feel light as a feather or did it have some heft to it?
• It’s possible there is crack in the carb housing where fuel enters and or where the seat is screwed in. Look closely with good lighting.
• Is there a gasket under the seat where it meets the carb? Most do have that, unsure if yours requires it, but also a source of gas coming in even though the needled is fully seated.
• Inspect the needle and its seat. Any damage or debris?

Any other suggestions from the community?

 

[Mymarcec]

It's the black rubber float and it felt light, although I've never felt the weight of one before.

I'll try the rest. I know someone that might have the same carb, and will see if I can try a swap.