My A4 adventures

[Ando]

Updates from this morning’s work:

a. The issue with it only running on 3/4 choke: The carburetor came off and was rebuilt with the proper (ie late model) rebuild kit. Ran the motor and sadly have to report that the engine still stalls when the choke is lowered (even when lowered just a little bit). There’s also a small gas leak in the aft section of the carb. Looks like it needs to come off again;

b. the vacuum port (PCV) spacer is off to minimize potential vacuum leaks,

c. the manifold: the bolts were be torqued down but there now seems to be blue/white mist emanating from the space between the manifold and the engine block. As I mentioned in the first post, this is an engine that I purchased. Of all the things I’ve worked on it, the manifold isn’t one of them and it looks like she may be punishing me for it. It looks to me like it could use removal and inspection (and a new gasket). I have unsuccessfully tried to attach a video of the mist for you all to review. You would see that there is the same mist coming from the oil fill area too.

d. the exhaust connection to the manifold: no leaks

e. Batteries: new and working really nice;

f. Thermostat was, in fact, reseated properly, as the water has stopped leaking from it;

g. Fuel storage and delivery problems, still waiting to be solved later.

[ndutton]

Is your adjustable main jet closed all the way?

[Ando]

Is your adjustable main jet closed all the way?

I think not, but I'll double check. Thank you

[Ando]

Mist video (still not that easy to see what I'm referring to)...could this blue/white mist be caused by the lifts/springs being in need of replacement? I ask because I can see one of the springs when I open and look down into the oil fill cap (where some of the mist is coming from) and I have not changed the lifts or springs on this new old late model. I plan on removing the manifold, inspecting it, putting a new gasket on it and see if that resolves the problem, but that doesn't resolve the mist coming from the inside of the oil fill area. Am I on to something?

https://youtu.be/PIAjMR-Y9PY

[Ando]

Carb: I think I may have found the issue. The early model carb kit I mistakenly ordered for my late model carb came with a shiny adjustable main jet. During my first rebuild, I did not replace the original main jet with the new one. What I did replace was the quick drain main passage plug and guess what I put in its place? Yup, I put the shiny adjustable main jet in its place ...and probably threw away the quick drain main passage plug (I think I have a spare...from the carb on the other engine). Oh and I backed it out two and a half turns ha! As for the original adjustable main jet, its backed out one and a half turns.

Will be working on all that when I take the carb out...once AGAIN

I wonder though if that really could cause the engine to stall. We'll see, I guess on the next report.

[ronstory]

Do you have studs on the carb? IMO, it makes a world of difference in the easy of swapping a carb in & out.

[Ando]

Do you have studs on the carb? IMO, it makes a world of difference in the easy of swapping a carb in & out.

Yes, I do. I never thought there was a different method...What would the other option be, just out of curiosity?

[ronstory]

The old fashion way, studs inserted into the manifold or in the case of the A4... thru bolts. Yuk!

I know when I got my first A4 and tried to reinstall the carb with thru bolts, Ouch. That got fixed with a 25 pack of 5/16" SS Allen heads... So I still have a few left.

[Ando]

Today’s update:

Manifold: I disconnected the exhaust from the manifold (that connection was the same one that I had just recently sealed using Neil’s paste to prevent exhaust fumes from leaking from...and it worked perfectly mind you so I was sad about that and sad bc I now need another gasket for that connection). I disconnected the lines and, after an hour or so trying to pry and pull, I finally took off the manifold for the first time and found the following:


Big thanks to Neil for teaching me that the sooty ports are the exhaust ports (1 at each end and 2 in the middle) the clean ports are intake.

Cleaned it up with a wire brush and put in a fresh gasket thanks to the full gasket kit that came with the engine. Here’s how it looks now:

Neil also lmk that the manifold gasket goes on dry and is attached dry (no sealant at all).

The mist: it’s blowby, but since compression is good, there’s no need for a valve/lifter replacement. Maybe need a PVC system eventually.

Carb: the carb is off and the mistakenly installed early model main jet has been removed and replaced with the late model main jet. Now off to the garage to see if I can use the main plug from the carb at home. Big thanks to Ken for the tech support on this main jet/plug issue. Btw, he told me that the electric fuel pump has to be be one that has 2 or 3 psi and to check, I’d have to look up the serial numbers that are on the pump itself.

To do list:
1. Get gasket for exhaust/manifold connection
2. Find or buy main jet plug for carb
3. Install manifold, exhaust and carb
4. Check to ensure the electric fuel pump is one with 2 to 3 psi
5. Run a test
If all is well, then
6. Resolve fuel delivery issue (Maybe related to #4 above)
7. I guess I should clean her up a bit too
8. motor out a bit and dare I say...maybe even set sail?
9. either Paint the deck and/or Install EWDS and refresh the instrument panel

[Ando]

I got the following checked off my to do list:

1. Get gasket for exhaust/manifold connection (Done this morning)

2. Find or buy main jet plug for carb (Found one on my other carb at home...I also found that the spring that engages the choke was missing and replaced it with the one on my doner carb)

3. Install manifold, exhaust and carb (I just might be doing this tonight if I get out of the office early enough)

4. Check to ensure the electric fuel pump is one with 2 to 3 psi (will probably be the first thing that I do tonight and, again depending what time I get out of the office, maybe it will also the last thing I do)

Next things on the list:
5. Run a test
If all is well, then
6. Resolve fuel delivery issue (Maybe related to #4 above)
7. I guess I should clean her up a bit too
8. motor out a bit and dare I say...maybe even set sail?
9. either Paint the deck and/or Install EWDS and refresh the instrument panel
10. Continue disassembling the early model A4 that's in my garage. For this one, all that's left to do is remove the springs, lifters and cam shaft so I can take the block, head, crank shaft, pistons etc to the machine shop for Dyno testing, honing and machining. Then POR-15, paint, reassemble and put in a display case

[Ando]

The adventure continues:

1. I installed the manifold, exhaust and carb (I learned that it is a whole hell of a lot easier to install the exhaust to the manifold when the manifold is off the block...I had planned to spend most of my day installing these three things and I was really not looking forward to the maniforld exhaust connection. But, with the manifold off, it took literally such a short amount of time that I found myself asking what else to do with the rest of the morning, not to mention the rest of the DAY. Felt good). So I did some extra credit work:
1a. Cleaned her up inside and out;
1b. Sanded and varnished all the teak

2. BTW, I checked to ensure the electric fuel pump is one with 2 to 3 psi and found that it is NOT. Its actually a 4-5.5PSI and I found that out only by removing it and wire brushing the metal brackets to reveal six numbers, which I then cross referenced on the Facet website to get my answer. I learned that I really really dislike that one aft bolt holding that fuel pump...any suggestions on a work around? A longer bolt might help, I guess).

3. Ran a test and was getting threatened with a stall from all sides (i.e choke, throttle etc.) Ndutton helped, remotely at first, then dropped off a carburator he knew worked well. I learned what a throttle stop is (its the small screw where the throttle cable connects to the carb) and what it is used for (the best I can describe the purpose of this thing is that it adjusts the position of the slowest/lowest point of the throttle lever in the cockpit, which, in turn sets the idle at a sweet low point).

4. I installed Ndutton's carb and had the same problems until, upon his suggestion, I adjusted the throttle stop and MY GOD she's running! Not only running, guys and gals, running super super quiet and smooth and sweet. Then I basked in the sunshine (both figuratively and literally)
NOTE: Looks like my "doner carb" from my other engine just became my go-to carb because my carb has some sort of air leak causing it to threaten a stall. Upon reflection, this stalling is the very same issue that brought me to this website in the first place. I was rebuilding and rebuilding a dead carb and blew my engine doing it. So, I will rebuild the other carb before putting it on (it'll be my 3rd rebuild experience) and test it and give Neil's awesome carb back, which should be painted gold because that's just how awesome it is.

If all is well, then its on to:
5. Resolve fuel delivery issue (Maybe/hopefully related to #4 above. I dont know because I have been using an external fuel can as my source of fuel for all these tests...maybe I should try installing my actual fuel line before removing Neil's carb???)

6. motor out a bit and dare I say...maybe even set sail?

7. either Paint the deck and/or Install EWDS and refresh the instrument panel

8. Bossum chair my butt up the mast and repair the lights and install a line or two for flag waving

9. BTW, I received the spring lifter tool ($27+shipping from MMI) which will allow me to continue disassembling the early model that's in my garage. Once I remove the springs, lifters and cam shaft, I can take the block, head, crank shaft, pistons etc to the machine shop for Dyno testing, honing and machining. Then POR-15, paint it gold , reassemble and put in a display case.

[ndutton]

Additional information

Previously the engine would only run, albeit poorly, with about 3/4 choke. Ando installed a new manifold gasket on principle to be certain there was no intake leak. He also removed the PCV spacer between the carb and manifold to eliminate a second possible leak source and new gaskets all around. He described the test that followed, still ran only with choke but not quite as much.

He was able to try some carburetor adjustments, particularly the idle mixture. He reported it seemed to run a little better with the mixture screw turned all the way down to its seat. This indicated the fuel-air mixture was off, either short on fuel or long on air.

He had rebuilt this carburetor a few times, at least one of those with the wrong body half gasket (early model gasket on a late model carb) but the current configuration was correct. He was careful to rod out the tiny passages in the carb throat and set the float correctly. For me, I was done with this carburetor. ENOUGH!

The first test with my spare carburetor was not a total success. With the idle mixture screw preset a 1¼ turns off its seat Ando reported it started easily, ran with no choke at all but would stall if either choke was applied or the throttle was run to its lower stop. I figured the engine was warm enough from the test run to not need choke and 1¼ turns off the seat was probably a little rich (a direction I wanted it to be given the earlier symptoms) so application of any choke would cause a stall - as it should so all good there. For the stall at the low throttle stop I suggested tightening the throttle stop screw which solved it.

I want to repeat that Ando did all of this on his own with his MMI manual and a little advice along the way. It has taken a while but I did not turn any wrenches and that was intentional. He started as an admitted total newbie and at this stage he has replaced his engine (for other reasons) including reconnecting everything, worked through troubleshooting non-starting and later non-running problems with little improvements every step of the way. He isolated the on board fuel system problem (yet to be chased down) with an auxiliary tank so troubleshooting could proceed. He learned how to perform a compression test, how to set the timing from scratch and what certain symptoms indicate.

When we both have time available I'll make another visit to his boat to fine tune the timing and carburetor settings but that will only be refinements. We will develop a strategy for the on board fuel system problem too.

[Surcouf]

great thread for the others around. Thank you for reporting progress and issues...
-- It has comforted me in my intentions not to overhaul my carburetor before I pass my engine-in-overhaul on its test bench: my engine was running decently before, so if I have issues restarting, I prefer not to add the carb on the list of things I could have messed up with. If engine runs, then only carb will gets its overhaul too.
-- POR-15: great paint, but lesson learnt: go down to bare metal. No POR above an old paint.
-- thank you for all the tips on carb tuning / chocke cable etc.. something tells me this is going to come handy quickly.
Only comment: not many pictures, and I love engine pictures.

Good luck for the rest!

[ronstory]

The adventure continues:

2. BTW, ... my answer. I learned that I really really dislike that one aft bolt holding that fuel pump...any suggestions on a work around? A longer bolt might help, I guess).

9. BTW, I received the spring lifter tool ($27+shipping from MMI) which will allow me to continue disassembling the early model that's in my garage. Once I remove the springs, lifters and cam shaft, I can take the block, head, crank shaft, pistons etc to the machine shop for Dyno testing, honing and machining. Then POR-15, paint it gold , reassemble and put in a display case.

Regarding the install of the facet pump on the block, I bought two 2.5" long bolts (partially threaded) and jammed a nut up to the end of the tread with of bit of JB weld for permanence. Much easier to control where the end of the bolt need to be... and next time I would make it even longer, perhaps 3" or 3.5" long.

As for dyno testing the A4, we really want video.

[Surcouf]

Regarding the install of the facet pump on the block, I bought two 2.5" long bolts (partially threaded) and jammed a nut up to the end of the tread with of bit of JB weld for permanence. Much easier to control where the end of the bolt need to be... and next time I would make it even longer, perhaps 3" or 3.5" long.

As for dyno testing the A4, we really want video.

Regarding the partially threaded bolt: boy this is so freaking smart and simple... Love it.
Regarding the dyno testing: this is something I would NOT try with my rusty block, but I would love a video too!!!