New Atomic owner with problems

[filbert99]

Hello all. New member here looking for some help or observations.

I've been the new owner of a 1974 Tartan 30C with an Atomic 4 in it for about 3 weeks now. The boat was completely restored by the PO with the exception of the motor. He stated that the motor was "old and tired". Long story but he needed to get rid of the boat and I bought it knowing that I could be looking at a replacement job. The info I got was that if all I wanted to do was get in and out of the marina, it should be OK for a little while but warned me that it was running hot.

I timed my 35 mile run to the new marina to take advantage of wind and currents but was forced to motor for a bit at the beginning and end of the trip. The motor ran very hot (210) and relatively low RPM's for about an hour. This got me into an area where the wind was good and I shut things down and sailed for about 6 hours until the wind died. At this time, we were about 5 miles from the marina so I made the decision to start back up and motor in. Starting up did not prove to go so well. After repeated attempts, it finally started on what felt like 2 cylinders and ran that way for 10 or 15 minutes (very hot once again) and then felt like it was kicked into running on all of the cylinders. This took about an hour but we made it safely into the new slip.

Now the trouble starts (or continues).....

The next day, all attempts to start the motor failed. pulling the plugs revealed several stuck intake valves. I pulled the head, started doing some research, called Moyer, talked to Ken and got some parts coming my way.

I took the head to a machine shop and had it checked for warping. They put it on some kind of surface sanding machine and said it looked good. No sign of cracks or corrosion that we could see either.
Next, i went about pulling the valves. All of them came out OK except the intake on cylinder 4. It only came out by taking the valve guide with it. All of the intake chambers were absolutely coated with a black, sticky tar like substance. I ordered a new valve, guide and heavier duty springs and set about cleaning up and reinstalling the valves and head.
After several conversations with Ken, I learned about the dangers of seawater ingestion on a hard starting motor and followed his advice when I was finally ready for the restart.
I had a very difficult time getting it restarted but finally figured out that it was primarily a fuel supply and timing issue. Once it did get started, I opened the seawater valve to see how the cooling was doing. Since I cleaned up the water jacket, checked the thermostat, put in a new diverter, installed a brand new manifold, checked the exhaust and replaced a very worn impeller, I figured it would run nice and cool. Not a chance. right back up to the 200+ mark in no time at all.
Next....Check all cooling channels as best I could. Every indication was that there weren't any major restrictions. The pump, however, seemed to be very weak. I have the N202M3 pump that looks like an upgrade and rebuild are in order. But after cleaning it up and reinstalling it the motor seemed to be cooling OK. I still plan to order an upgrade tomorrow but decided that it was time to take the boat out for a shakedown....
Problems right away.....As soon as I backed out of the slip and shifted to forward, the engine died. Got it restarted and motored out to the waterway (5 min) before I shut it down for temperature (again!). Prior to the shutdown, one passenger that was down below complained of an "exhaust,oil smell" in the cabin. I attributed this to burning off any residual oil from the work that was done. Also, the shutdown process was accomplished by simply taking it out of gear. It died as soon as I did that.

Now the sails are up, everything is quiet, and we're discussing possibility of linkage/gas/carb problems causing the stalls and and a new water pump upgrade to rectify the cooling issues.

Now it's time to head back in. sailed in as far as possible to limit the run time for putting it in the slip. Followed the raw water procedures prior to start up. (The motor also required full choke and full throttle to start quickly but I'm attributing that to carb issues). As soon as it started, I had a loud ticking noise that sounded like an exhaust leak. I motored it up to get enough momentum to put it in the slip and shut things down. Time to give up and go home.
This morning I went back to the boat and decided to do a compression check. I didn't want to start it quite yet so I did the first check on a cold engine. from 1-4 got 60,80,70,75. Started it up and had massive exhaust blowing out the starboard side through the gasket at the No. 1 cylinder.
Head is off with a clear indication of exhaust blow by between the top gasket and the head.
Frustration level 11...............(and sorry for the long post)

[hanleyclifford]

Welcome Phil. You did not mention whether you checked the passages in the manifold. The fitting where the cooling water exits the manifold is possibly the #1 culprit in overheating issues.

[roadnsky]

When you replaced the head, did you use one or two gaskets?

[Trés 30]

Filbert,

Wondering what condition your exhaust system is in and how much water/exhaust is coming out of the hull. Here's what mine looked like before replacing it

Also, I learned from a friend's boat that old exhaust hoses can collapse inside while still holding their outer shape, causing complete blockage.

From your journey thus far sounds like you know your way around pretty well, but still make sure your plug wires are in the right order (1-2-4-3). You've covered a lot of ground in 3 weeks, maybe a little too much

I'm guessing you have the MMI manual, but if not definitely buy it, worth every penny.

Welcome to the forum! (and we love pictures)

[Al Schober]

Filbert,
Good choice of boats! Now let's get the engine up to par.
Recommend you get rid of the thermostat and also plug the bypass, if you have one. Get all the coolant flow going through the block. Once things are cooled off, then we can worry about bring the temp up - if that's what you want to do. Personally, I've tossed my thermostat, have a heat exchanger & glycol cooling, and haven't seen a temp over 120 F in 20 years (except for...).
Wonder if you have a photo of the top of the block with the head off? The cooling passages by the valves are known spots for blockage, and the 'concrete' blocking them has to be chipped out.
Oh yeah - don't give up yet. The A4 is a good engine, certainly the equal of a Tartan 30.

[Mo]

Hi, welcome aboard. Here's what I'd do:
1. Get an MMI manual if you don't have one.

2. Call MMI and order headgaskets (takes 2). It's a waste of time and effort to try and reuse the old ones. You may have just purchased gaskets on your previous repair...they are done now so don't reuse.

3. Remove T-stat and put in a by-pass valve. With this valve you are going to restrict the flow about 1/2. Dave Neptune also came up with a modification that works as well. Allot of issues regarding steam out the exhaust, restricted flow, also come from Thermostat failure...however keep in mind there generally is still some flow out the transome. If the previous owner had a by-valve in there just ensure it works, OK.

4. Exhaust Manifold blockage. Hanley was right, they can be a problem and even harder to diagnose. If we pressure test with air the air will either hold or not. Blowing air through it doesn't do much for cleaning it out. Flakes of rust can actually be moved up to cause a restriction when the pump is forcing water through it...water stops, rust falls back down and may not happen each time. So ensure you take out the NPT fitting in the exhaust manifold as well and ream it out removing any loose particles of rust and or buildup.

5. Have a look at your plugs. Gas on a plug is wet looking...but droplets on a plug IS water. Those compression numbers don't give me a warm and fuzzy feeling but a leaking headgasket from overheating...sure, it's possible to drop all four out given the right circumstances.

6. Your hard starting could be related to the drop in compression and there may even have been some water getting at the plugs from the headgasket issue....I think it will resolve once you tend to the headgasket.

All the best.