Cranking raw water cooled the engine too much then vapor or smoke

[BadaBing]

Does it seem odd to anyone other then me that the water exits the exhaust manifold via an childish red hose, leaves the engine compartment then returns.to the engine compartment as a black hose to connect to the port on the how section. Also very new rubber exhaust hose with new as hose clamps.

A very clean engine compartment. Nice and tidy.

[redtim]

Does it seem odd to anyone other then me that the water exits the exhaust manifold via an childish red hose, leaves the engine compartment then returns.to the engine compartment as a black hose to connect to the port on the how section. Also very new rubber exhaust hose with new as hose clamps.

A very clean engine compartment. Nice and tidy.

Can't comment on the why for those hoses, but the red one runs to an anti-siphon, which the black hose is attached to.

[67c&ccorv]

Looks good - definitely a late model.

Your engine should be pumping water out the exhaust immediately upon startup...I would start by checking the thermostat for proper operation.

[redtim]

I'm thinking about changing this thread title to "the idiots guide to engines"

Took a pleasant sail out to McCovey Cove last night to catch the giants game, about halfway across the bay, the wind died, so fired up the engine. ran for about 30 minutes, then died. oops, out of gas. Cranked a while with the intake closed, got her started again but forgot to open the seacock remembered after a minute or so, saw a significant amount of steam coming out the exhaust. When I opened up the water again. I got a significant amount of black crud pushing out with the water, and a bit of steam that dissipated within a minute or so. All seemed fine during normal operation, docking, leaving to pick some people up, then when I was dropping anchor in the cove, i was reversing to set the anchor, throttled up to about 2k rpms then down a bit and the engine started running rough and died. Couldn't restart, would try to to turn over or catch for a second then die, eventually with some choke and throttle up halfway, she started, but would not run at low rpm. Motored home in this condition, ran smooth at 14-15 all the way home, died again when I was pulling into the dock and trying to slow down.

I'm starting to think this is a carb problem. Going to replace the fuel filter, and add a 10 micron polishing filter. Guess I'll be pulling the carb apart and cleaning it this weekend too.

Any thoughts nuclear sleuths?

[hanleyclifford]

I'm thinking about changing this thread title to "the idiots guide to engines"

Took a pleasant sail out to McCovey Cove last night to catch the giants game, about halfway across the bay, the wind died, so fired up the engine. ran for about 30 minutes, then died. oops, out of gas. Cranked a while with the intake closed, got her started again but forgot to open the seacock remembered after a minute or so, saw a significant amount of steam coming out the exhaust. When I opened up the water again. I got a significant amount of black crud pushing out with the water, and a bit of steam that dissipated within a minute or so. All seemed fine during normal operation, docking, leaving to pick some people up, then when I was dropping anchor in the cove, i was reversing to set the anchor, throttled up to about 2k rpms then down a bit and the engine started running rough and died. Couldn't restart, would try to to turn over or catch for a second then die, eventually with some choke and throttle up halfway, she started, but would not run at low rpm. Motored home in this condition, ran smooth at 14-15 all the way home, died again when I was pulling into the dock and trying to slow down.

I'm starting to think this is a carb problem. Going to replace the fuel filter, and add a 10 micron polishing filter. Guess I'll be pulling the carb apart and cleaning it this weekend too.

Any thoughts nuclear sleuths?

Sounds like you may have cooked the crud in your combustion chambers but only spitted a portion of it out. Try a new set of spark plugs.

[Borrowed Time]

Hi Redtim,

A couple years ago, I started my A4 as usual at the dock to warm up prior to a sail to Catalina. When the engine died a few minutes later, I found I had failed to open the fuel petcock and so starved the old girl for fuel until she quit. So open petcock, close the raw water intake, full choke and cranked until she fired up. Then I motored out of my slip for 30 minutes as usual to the outer harbor and sailed off to Catalina. Somewhere across the channel, the wind died and so fired up the motor again and ran for another hour or so until we reached Avalon. When I met up with the harbor master to rent a mooring, the motor died at low idle and would not restart. The harbor master towed me to my mooring and wished me luck.

I managed to get the A4 to run well enough at medium to high RPM so that I was confident it would run me up the LA Harbor's main channel back to my slip. When I got back, I took the carb home and squirted carb cleaner all over inside and out, let it dry a bit and reinstalled it with new filters and problem has not recurred. I am sure I sucked up a bit of crud and it lodged in one of those tiny little places in the carb. (Note to self: buy a new filter cartridge.)

As for your white smoke billowing out your transom's exhaust port, I think that is a separate issue. The low volume of water discharging at low RPM suggests restricted flow I would look at the exhaust manifold for accumulated crud. It is amazing how much I found in mine when I was having cooling system issues. ( I wound up with a new MMI pump, all new hoses, new thermostat housing, flushed out water jackets and manifold to solve my issues. Of course your mileage may vary.) You can readily check by one at the time disconnecting the water hose leading from the thermostat housing to the exhaust manifold and comparing the flow going into and coming out of the exhaust manifold. I found another poster on this board had reconfigured the plumbing to where the hose from the thermostat leads into the rear of the exhaust manifold in effect pushing the crud uphill and then out the front hose port. I have been using this plumbing set up for a couple of years now and it seems to be working fine for me. Attached is a picture of my A4 taken last night. It has been a journey, but this site has made it possible for me to figure out every system on this engine.

[redtim]

An interesting note on the water flow.

Before I pulled the carb this weekend I fired up the engine to see if the problem had been fixed by divine intervention. It had not What I did notice was the amount of water coming out the transom had gone up significantly. I'm wondering if this had something to do with all the black crud that came out after running a couple minutes with no water running through.

I'm going to clean out the carb today, throwing new plugs in, and putting a new fuel filter on there. Hoping to see some improvement in running condition. Thanks for the similar story, I'm confident this will resolve the new issue, and will at least eliminate the fuel system from my list of possible causes for low rpms

[redtim]

Closure!

Posting this to help anyone that comes across this thread.

After all this futzing around, I finally decided to check on the timing. I'd been a little intimidated to mess with it, but boldness was in my favor this time. At my 1500 rpm max setting I turned the distributor a few degrees clockwise, and could hear a definite increase. Got them to where I felt the max was and called it good.

Went back a couple days later, and I could not get the damn thing to start. A few dieseling chugs then dying was all i could get. Figured I must have turned a little to far, so dialed back and had a bit more luck starting, but still running rough. At this point I adjusted the idle mixture, I ran through a lot of positions here, so I can not say for sure whether it was leaner or richer, but after dialing that in, the engine is running really smoothly.

I was out by myself, so didn't want to test my luck too much running under WOT, but at 17-1800 I was doing 5.5 knots.

Many thanks to all on the forum for your input through all the posts on this forum. I never would have been able to get this all fixed up without you all.

[david78212]

Do you regularly run at WOT? because you know it's not a speedboat... right?
I suggest you spend $47 on the manual and start going through the engine... you really can't be sure what was and what wasn't done to it. Looking at the multi-color paint scheme "stuff" has been done, probably by several different people...

You should spend some time doing some preventive maintenance - i.e. plugs, points (if you still have them... you shouldn't) T-stat, impeller... before your engine becomes another "those DARN atom-bomb-4's..." and I don't really mean darn.

They run good, they're comparatively quiet, they're pretty simple... but you have to take care of them. Mine will push the boat to hull speed at about half throttle... nice to have a little extra in reserve.

[JOHN COOKSON]

I Didn't Reread The Thread

Did you check the choke to be sure it is opening and closing all the way?
Also did you check the advance to be it is working correctly?

TRUE GRIT

[sastanley]

red tim...A couple comments.

Where the black hose comes from the anti-siphon into the exhaust pipe...This is a common location for crud build up and reduced water flow. The mixer elbow itself is often filled with junk...

Also, as you noted earlier in this thread, you had better flow after crud blew out from a mild overheat event (run for a minute with no water) - I would also pull the red hose off the manifold and see if you have any stuff in there...that is the exit point of all cooling water from the motor and a good choke point for cooling system debris.

Now that you've solved some other problems (fuel, timing) - I'd do a cooling system flush..lite (vinegar), or heavy (muratic acid)

Immediately spend the $45 on the Moyer Manual!!

[redtim]

I do have the manual, never would have made it through without.

re: WOT, i haven't run it that hard except for a couple tests, did want to see what I could get away with at the top though, you know just to know

Now that we're running smoothly, i'll definitely start checking off all maintenance items.