[newhaul]

Newhaul-
"find a mechanic you can trust."
Reminds me of something Benjamin Franklin said, that any three men can keep a secret as long as two of them are dead. So any dead mechanic should be trustworthy, although, I'd still have reservations about some of them.
.

Sorry you feel that way there are many people that trust me to do the best job I can do on their vessels and I have been doing it for over 20 years so I must be doing something right

 

[dabnis]

Sorry you feel that way there are many people that trust me to do the best job I can do on their vessels and I have been doing it for over 20 years so I must be doing something right

If you have a big return clientele, you must be doing it right. When I said :

First, not all "professionals" are experts, or conscientious

I didn't mean to imply that all "professionals" do sub-standard work.

Paul T

 

[CalebD]

I left a clean white paper towel. If that thing is stained next weekend, then that HAS to be it. Either way, I know I need to pull the carb.

ALSO, the mechanic failed to seat the choke cable bracket correctly. Not sure if this has anything to do with it, but I thought I would mention it.

You are going to want to get a few oil absorbent pads at your local auto parts store to use instead of paper towel. The ones I use are white also. I keep one under my carb all the time to keep tabs on what might be leaking out. I also have some Marvel Mystery oil in my gas.

If the mechanic messed up the choke cable it is possible that your choke butterfly is not closing/opening fully which could cause you to burn rich or be hard starting.

 

[FirstCandC]

Pulled the carb this weekend. Was easier than I thought.
More gas found under it again. This time I left absorbent pads and sealed off everything, just in case the local insects were looking for a nice nesting spot.

Going to take it apart. Thanks again to all for your advice. The one thing I can't understand is why is it running rich while ALSO having a leak? Could a high float level cause leaking?

 

[CalebD]

Running rich implies too much fuel which is consistent with your carb dripping gasoline. It is leaking because there is too much fuel.
Yes, it is probably the float valve/needle that needs re-thinking.
I'd get the carb rebuild kit from Moyer (new gasket, jets, float needle etc).

 

[pdqaltair]

^^ Yes, that would be the obvious and common reason.

The float may also be heavy (leaked).

 

[dabnis]

If you are shutting off the gas at the tank, the leak may be from a loose fitting or a crack in the carb body, assuming the tank is higher than the carb. If the tank is higher & the fuel
is left on, & the float is set too high, or not closing, the leak could be from the float?

Paul T

 

[FirstCandC]

Update: took the carb apart and examined it closely. The float was indeed functioning. I also pushed the float down in a cup of water to see if it had any leaks. No leaks. Put it back together and installed it.
The engine fires up, runs steady (no more knocking), but still smokes. There is also what still appears to be some oily residue on top of the water from the exhaust. The oil pressure was steady at 40 psi. Oil level the same- not drinking oil. Set the mixture screw to one and half turns out. Tried turning it in half a turn and also the other way a half a turn. Doesn't stop the smoking/oily residue. I can't figure it out. Left absorbent pads under the carb. Going to see if it is still leaking on the next trip.
I guess checking the combustion is the next step. The only other thing I can think of is the Marvel Mystery Oil that is in the gas. I add a few ounces per gallon.

 

[dabnis]

Update: took the carb apart and examined it closely. The float was indeed functioning. I also pushed the float down in a cup of water to see if it had any leaks. No leaks. Put it back together and installed it.
The engine fires up, runs steady (no more knocking), but still smokes. There is also what still appears to be some oily residue on top of the water from the exhaust. The oil pressure was steady at 40 psi. Oil level the same- not drinking oil. Set the mixture screw to one and half turns out. Tried turning it in half a turn and also the other way a half a turn. Doesn't stop the smoking/oily residue. I can't figure it out. Left absorbent pads under the carb. Going to see if it is still leaking on the next trip.
I guess checking the combustion is the next step. The only other thing I can think of is the Marvel Mystery Oil that is in the gas. I add a few ounces per gallon.

I used to run all my 2 strokes at 50:1, which is about 2-1/2 ounces per gallon. Looks like you are running about the same ratio in a 4 stroke, which could be the reason for the smoking. If you can run a separate tank, an outboard tank, perhaps, without the oil, & after a while the smoking stops, there is your cause.

Not sure about the leak, but it is evident because the oil in the fuel doesn't evaporate, like the gas does.

Paul T

 

[hellosailor]

I generally don't believe in magic elixirs, my faerie godmother told me they are all worthless. But I must confess that I've only heard good things about MMO, from people who have had, ah, intimate relationships with engines. Even in that context, I'd also say run that fuel out, or switch your fuel supply to a smaller "just gasoline" mix to see how it runs. Is there a chance you misread or miscalculated, and added way too much MMO?

I knew someone who misread and added 1/4 cup instead of 1/4 tablespoon of vinegar in a chocolate cake mix. Um, yummy. (Not!)

 

[FirstCandC]

Yes, it is like cooking with wine- very easy to add too much!
Thanks for the tips, not giving up on this thing yet.
Would it be safe to disconnect the fuel line from one side of the engine side of the Racor filter and put the fuel hose down into a 2 gallon gas tank? I could plug the Racor and move the gas tank into the cockpit, away from any possible sparks.

 

[dabnis]

Yes, it is like cooking with wine- very easy to add too much!
Thanks for the tips, not giving up on this thing yet.
Would it be safe to disconnect the fuel line from one side of the engine side of the Racor filter and put the fuel hose down into a 2 gallon gas tank? I could plug the Racor and move the gas tank into the cockpit, away from any possible sparks.

Not quite sure if I am following your layout? However, I think if you shut the fuel off at the tank, disconnect, & drain the hose from the inlet side of the filter, & replace it with the hose from the outboard tank, which could be in the cockpit, hose length allowing, you should be OK?

Or, you could drain your onboard tank & re-fill with straight gas?

Paul T

 

[FirstCandC]

One final update- something told me to try pulling the carb one more time. Downloaded the carburetor video from the Moyer site, which actually addresses quite a few frequent issues. Removed the float valve seat and blew on it by mouth. Also used a sharpened dowel to clean out any tiny grit. Something must have worked right because she ran much better this time. No blue smoke and no residue on the water. After about one minute, however, a bunch of RUST came out of the exhaust, and then water stopped coming out.
Blockage in the exhaust or somewhere in the cooling system?

 

[christian.hess]

yes...I would not run the engine

take off manifolds...descale and clean exhaust ports well also clean all your water flow passages

you are deifinitely gunked up...the blue smoke could of been from overheating every time you got restricted flow in the system

 

[hellosailor]

A sharpened dowel? Interesting, but you might want to pick up some regular (not thick) pipe cleaners for that. Great for cleaning carb passages.

 

[RichH]

.............. After about one minute, however, a bunch of RUST came out of the exhaust, and then water stopped coming out.
Blockage in the exhaust or somewhere in the cooling system?

Slab Rust !!!!!
Very common on marine exhaust manifolds, especially on engines that are drained of cooling water when seasonally or long term stored on the hard.
What happens is that as the cast iron rusts it penetrates deeper into the casting exposing the 'stratifications' of the casting when it was made. Such flakes can easily block the outlet of the manifold causing overheat problems that mysterious go away when the engine is shut down (and the slabs fall back to the bottom of the insides of the casting).
Rx. - Remove the exhaust manifold, and get inside the manifold with a stiff wire and break loose the loose 'slabs'. DO NOT use any non-inhibited acid to clean out this manifold EVER again - only inhibited boiler descaling compounds such as RydLyme, etc. if there is significant 'fouling'.
Once you shake and blow out all the loose and broken up slabs from the inside of the manifold, perform a 'pressure hold' test on the manifold to validate that the manifold does not have a pin hole leak between the gas side and the water side of the manifold. Put a temporary 'cap' on one of the water 'nozzles' on the manifold to totally block flow, apply a pressure gage to the water hose that you will apply and connect to the 'other' nozzle and apply 30-40 psi pressure, shut off the valve to the hose and watch the pressure on the gage to 'hold steady' for 15-30 minutes .... and with NO water coming out of any of the gas passages.

To prevent slab rust, always use an antifreeze with 'rust inhibitors' when laying up the engine for long periods of time; AND, whenever possible always run the engine for long periods of time (such will form a 'protective' BLACK form of rust ... in the engine and in the manifold).
These manifolds are no longer easily or commonly available, so take care of what you have: run the hell out of the engine and always add antifreeze with rust inhibitors when long term storing the engine.

BTW the carburetors on such engines have whats known as an emulsion tube that meters the correct ratio of fuel/air. The emulsion tube are small brass tubes with a closed end and with quite a few holes in the sides of the tube. If you get 'any' dirt or debris in any one of those small 'side holes' in the emulsion tube the entire fuel/air mixture will radically change. ALWAYS inspect and clean the emulsion tube when suspecting air/fuel ratio problems - the main jet only controls fuel flow TO the emulsion tube. (You can convert these 'fixed' jet carbs to adjustable needle valve control to extend the time needed for routine emulsion tube 'maintenance and cleaning'). Best is to keep small 'dirt' out the carb in the first place by applying a precise 10µM 'filter' between the fuel pump and the carb ... even if you already have Racors, etc. in the fuel delivery system.

hope this helps

 

[christian.hess]

WORD

a tip on emulsion tubes is to remove them and soak them in a cleaning solution

to not attempt to use dowels or sharp objects or anything that is harder than brass

not only will you damage them physically you will damage flow and precise metering not unlike a jet or in EFI the tip of the injector

do not use 3m pads either as they score the tubes and again mess with flow

I have always had GREAT results by either buying deep claen carb cleaner solution or boiling all brass and or metal or die cast parts in pinesol then let sit overnight

you can also invest in ultrasonic cleaning

what rich says is spot on...

you scale and slab rust as he calls it is what I was reffering to. its also very possible again that your blue smoke was heat related and not even close to being carb related

for the most part blue smoke can always be associated with overheating and bad piston rings aka "oi burningl" in engines with valve stem seals this first...

again caused by overheating or drying up of the seals.

the common black smoke I have found on a4s is mostlt from bad timing using the points systems...basically owners dont adjust as frequently as they should per the manual. best bet is to go electronic if you havent already done so

you need a ballast resistor on some conversions.

on the a4 you will have best luck fixing your engine by taking off manifolds, and cleaning all passages once water flow is restored to stock or better and water pump is working correctly AND exhaust system is clear you are good to go on carb work

number 1 rule on engine diagnosing is to fix ONE THING AT A TIME. that way you can pinpoint fault and check improvements in gradual steps.

this is ESPECIALLY TRUE of carb work and TUNING.

the good news is the a4 carb is so damn simple.

 

[RichH]

Dont mess around with mechanical points on these engines. Get an electronic retrofit distributor module kit ... also requires a more 'powerful' ignition coil.
Suppliers of the modules: indigoelectronics.com or MoyerMarine.com.

 

[christian.hess]

yup the coil is what needs a big resistor on some installations

 

[miatapaul]

Dont mess around with mechanical points on these engines. Get an electronic retrofit distributor module kit ... also requires a more 'powerful' ignition coil.
Suppliers of the modules: indigoelectronics.com or MoyerMarine.com.

Yes an electronic kits are great. I had an old MG with one on it, and it would start first crank every time, well every time the starter would crank! But if I was on a hill it always started as I rolled down it!