Wingnut

Cast iron is really hard so any steel wire wheel is fine. At some point we will want to get each piston to the bottom of it's bore and do an oil test and visual inspection.but lets get the gasket off first as I don't like what I'm seeing between the cylinders. Hopefully it was only the gasket that took the hit. Piston tops are aluminum, and by getting the piston to the top of the bore, they are easy to clean with the same wire brush. Softer metal so go easy. If the deck cleans up good, then I'd do the dye penetrant test discussed earlier. Also, please get the lifter valley ragged off to prevent trash from dropping down into the oil pan. Did you do your timing chain test yet? W

Heads go to the shop as they are. Obviously a head gasket failure and it will be important to clean and examine the area of the block deck after you get the gasket removed. That has seen a lot of heat and my hope is that the block is not damaged. Get her buffed up with a wire wheel and the lay your machined straight edge across that area. They are not OEM gaskets either so she's been apart before. Based on what I can now see of the cylinder heads, it looks like we guessed right on the gasket set. I would not let the shop start on the heads until you confirm that you still have a viable block. W

The IAC valves ( Idle Air Control) will fail in two fashions. If the servo motor dies that is an electrical fault that the ECM will see, and set an "Engine Sensor" alarm. If they die mechanically, basically getting stuck in the wrong position now and then, drive-ability goes to heck, but the ECM stays happy. Some have said that they remove the IAC and clean the pindel, but I have never tried that as aftermarket replacements are not all that expensive, and it's a 5 minute change-out. W

Sorry too. Homey don't do Volvo. W

Had some time this morning to drill down into your top engine gasket set. Here is the other possibility and I included the link to Rock Auto. Going on memory here as Merc did not change over their Vortec design the same year that GM did, but if you look at the intake manifold to head gaskets, you will be able to identify which one you have. I tried to go back and look at your intake pictures, but they are not there anymore. I think the first number I gave you is the correct one, but to be sure take a quick look at the attached link and photo. I also included a link to the best thread sealant I've found for head bolts. As far as questions go, our motivation is to prevent new owners from making the same mistakes as we did. Hardest part is the control of miss-information. Take your time, buy quality parts, and ask your questions before turning your wrenches and you will be fine.You and I know that any shop would hand you a bill for something north of 4 grand to pull this off. W https://www.rockauto.com/en/moreinfo.php?pk=8006720&cc=1031555&jsn=620&jsn=620 https://shop.advanceautoparts.com/p/permatex-thread-sealant-with-ptfe-1-oz.-80631/16160028-p?c3ch=PLA&c3nid=16160028-P&adtype=pla&gclid=EAIaIQobChMIhd_QgIGq4gIVAp7ACh1yuQPTEAQYAyABEgKxRvD_BwE&gclsrc=aw.ds

As with all loans, I would think that it depends on the individual's overall financial situation. So many out there figure if they can make the payment, then they can afford it. Dad always told me there is no better rate than NO INTEREST. Smart man. W

If you have the early style one piece intake manifold, then the gasket set I specified may not be the right one. That's why I said that you would need to match the intake gaskets in the picture to the ones on your engine to be sure. This takes some effort to get it right but the "marine" gasket sets are so stinking expensive it's worth the effort. The automotive engines from the factory don't have exhaust manifold gaskets, but all marine engines do. The Fel-Pro kit includes exhaust gaskets in case an older engine were to have some warp-age. If they compare nicely to your OEM Merc originals, then you're covered. Head bolt kit number looks correct, but you will need 2 sets, one for each head as that is how they are sold. As Doc said, sealant on thethreads as they screw into the water jackets. W

His was a 305, and yours will need the Vortec 350 kit as head gaskets are different. Unlike the automotive counterpart, your manifolds are gasketed too so those are a separate OEM Merc purchase. Also, be careful when you bolt the two half's of the intake manifold together, as you are dealing with plastic. Real easy to dislodge the massive O-ring and end up with an oil leak. Also, order new head bolt set as this engine uses stretch bolt technology and the old bolts are not to be reused. The Fel-Pro number should be your kit, just take a look at the intake manifold gaskets to be sure they match your existing, and this kit comes with exhaust manifold gaskets but they are not Marine spec. W FEL-PRO HST7733PT16 {#HS5746C}

The newer ECM managed engines rely on input from both the crank position and cam position sensors. When the relationship between the two gets out of range, the software can get confused and create a miss fire. In the old days, retarded valve timing often got compensated for by an increase in ignition timing as a tech would simply advance the distributor during the next tune-up. As Curt said, sooner or later the chain would fail and either cause a no start condition or the pistons would smack a valve or two and it would get really expensive. Timing cahin failure is rare now days as they use double row roller chains which will live for 1,000 hours with the modern oils available. My only other comment is cleaning the throttle body. In the future consider removing the body as it's only a few bolts. Then remove the throttle position sensor to prevent damage before using the carb cleaner. 2+2 Gum Cutter seems to work the best. After you finish with the cleaning, soak the throttle plate, cross shaft and body bushing with CRC or similar product. The cleaning has removed all the lubrication and you don't need future wear there. Everyone is quick to spray cleaners into the air intake, with little regard as to where all that crap is heading. Better a puddle of black mud on the work bench than on valve seats and cylinder walls. W

I hate to say this but it sounds like they replaced the impeller, but not the wear plates. A used, healthy impeller over time wears into the groves in a damaged housing. Put a new, flat impeller in there, and they don't pump near as well as the old one. The flat ends of the impeller need flat end plates to seal or they will by-pass internally and refuse to prime, especially on muffs. The only other things to check is if you have the single point auto drain system and it was left in the "armed/drain position" or the suction hose quick coupler is not nested together completely. Either way, I'd take her back. W

The CRC is to protect the raw cast iron cylinder walls that have been exposed to some coolant. The center piston rings are cast also, so soak down the bores and piston domes really good. There is plenty of oil film in the lifter valley to protect it. Just keep the opening covered with rags to prevent debris from getting down in the sump. You will want to crank the engine over by hand a few revolutions while you are spraying the CRC to make sure the entire cylinder bore has a film of oil. As far as the machine work goes, make the shop aware that you had over-heating issues, and that they need to deck the heads, inspect the valves and valve seats and replace as necessary. Complete valve job, inspect and/or replace valve guides as needed, and shim the valve springs or replace them if they are out of spec. A top shop will have the ability to pressure test the finished assembly, but at the very least they need to crack check the castings via the magnetic particle or dye penetrate method. If you buy your complete upper end gasket set now, you can give the shop the included valve guide seals so that you don't have to pay the shop to supply them. While the heads are away on their vacation, it's up to you to get the block in shape which includes cleaning all the gasket surfaces with a scraper and wire wheel. After you have them looking as new, use a steel precision straight edge, flash light, and a set of feeler gauges to confirm that the block decks as not warped. Put the steel on it's edge, across the sealing surface at several locations and use the thinnest feeler gauge in the set to see if you can pass that thickness under the steel. .002" is too much. Lastly, obtain a dye penetrate test kit on line, and follow the directions so that you are sure there are no near invisible cracks in the block. We now know that you had combustion gasses sneaking into the cooling system, and we are assuming that a head gasket had failed, but need to be sure. If you plan to skip this step, then figure on doing the air test after you get the heads back on. Lastly now is a good time for secondary maintenance, and if you have not checked the timing chain for slop, it's easy to do and costs nothing. Be a real shame to fail an old chain in the future and have all those shiny new valves get bent. Even the starter is right there staring up at you and a quick trip to the rebuild shop would buy you another 15 years. Distributor cap, rotor, plug wires, all right there right now. W

It's not a rocker switch on the helm grouping? W

My dealer installed Interstate Marine batteries on my 256 SSX in 2008. 10 years later, one tested good, and the other tested great, but I caught a sale and replaced in kind as I figured I was running on borrowed time. ECM's don't like deep cycle batteries so Merc specifies two starting batteries, and I went with the same Interstate 1000 CCA Marine for around 103 each. Never found a reason to spend the extra money on glass mat batteries as my house loads are minimal. Engines like the high surface voltages provided by a starting battery as it provides excess starter current while not robbing initialization current away from the ECM during start-up. Deep cycle batteries limit their output to a constant 12 vdc, for a longer period of time which is great for lighting, refrigerators, televisions, and radios, but engines need the extra boost to get things going. Interstate 1,000 CCA conventional wet batteries for me. Volvo had a bulletin out warning against deep cycle battery use as a primary as strange things were happening when the ECM was seeing less than 13vdc. W

I took my ride out on Tuesday and water temperature was 64 degrees, and barometer was in the mid 30's. New plugs, plug wires, fuel filters, and a full load of mid-grade. Bounced the thing off the rev-limiter for the first time since I owned her as conditions were perfect. On my 256 SSX, that's 64 mph. Going up into the 90's here tomorrow so that's the last time I'll see that this season. As long as you did not feel anything funny like a slipping coupler, or cone clutch, enjoy the summer W.

I pulled apart a Marine domestic water heater and found that the owner had "thought" he had winterized properly, but the internal aluminum tank had a 2" split at the seem from freeze damage. I welded it back up, and it was still fine 10 years later when he sold the boat. You might want to tear into the water heater to see if it can be repaired. Many shops can weld aluminum. You mentioned that your freeze plug in the engine popped out, which is an indication that the water jacket is not draining properly. You may want to remove the two drain plugs on either side of the block and get a drill rod up in there to clear any sediment from the water jackets, ensuring proper engine cooling and affirming that all the raw water is drained before adding the antifreeze. W

The code will clear itself as soon as the cause of the fault is rectified. There are a few sticky codes designed to stay in the histogram to be referenced by a tech with a scan tool, but they are few, and your user display will clear as soon as you repair the problem. W

A beep every two minutes limits the alarm category by a bunch. These are considered informational, non-critical alarms and usually mean a sensor failure. Look at the list below and notice the ones that say 2 beeps per minute. Likely a bad IAC valve, but without a scan tool it is hard to narrow down. The good news is it's not a true overheat, low oil pressure, low drive lube, or low raw water pressure issue that would do harm in a hurry. If the alarm causes a power limiting situation, then look to the "Available Power" column which may help narrow the possibilities down even more. If it is the IAC (common) that is an easy repair. W Warning System The engine warning system incorporates an audio alarm and, if installed, a SC1000 System Monitor. When the key switch is turned to the ON position, the audio alarm will momentarily activate to test the warning system. The alarm should sound once if the system is operable. This table is a guick guide, showing what warning output will accompany a fault. Fault SC1000 Audio Alarm Available Power Description Cam Sensor Yes 2 Bp/min 90% Open or short, engine must be cranking to set this fault code. ECT CKT HI Yes 2 Bp/min 90% Open ECT CKT LO Yes 2 Bp/min 90% Short ECT Coolant Overheat Yes Constant 6-100 % Engine guardian overheat condition EST 1-8 Open Yes 2 Bp/min NA Coil harness wire open EST 1-8 Short Yes 2 Bp/min NA Coil harness wire short Fuel Injector 1-8 Open Yes 2 Bp/min NA Fuel injector wire open Fuel Injector 1-8 Short Yes 2 Bp/min NA Fuel injector wire short IAC Output Yes 2 Bp/min 90% Only with rpm Knock Sensor 1 Yes 2 Bp/min 90% Alarm sounds for 20 seconds in NEUTRAL and indefinitely in gear. Knock Sensor 2 Yes 2 Bp/min 90% Alarm sounds for 20 seconds in NEUTRAL and indefinitely in gear. Low Drive Lube Strategy Yes Steady Bp 0-100% Low oil in sterndrive Low Oil Pressure Strategy Yes Constant 0-100% Low oil pressure strategy MAP Sensor 1 Input High No 2 Bp/min 90% Short, no visual on SC1000 MAP Sensor 1 Input Low No 2 Bp/min 90% Open, no visual on SC1000 MAT Sensor Yes 2 Bp/min 90% Open or short in MAT circuit NOTE: If any 5v sensor becomes shorted to ground the engine will not start. If the engine is operating when the short occurs the engine may stop operating and will not start. Fault SC1000 Audio Alarm Available Power Description Oil PSI CKT Hi Yes 2 Bp/min 90% Short, defaults to 51.7 psi Oil PSI CKT Lo Yes 2 Bp/min 90% Open, zero oil pressure Overspeed Yes Constant RPM Limit Engine over rpm limit Port EMCT CKT Hi Yes 2 Bp/min 90% Open, defaults to 32 degrees F (0 degree C) Port EMCT CKT Lo Yes 2 Bp/min 90% Short, defaults to 32 degrees F (0 degree C) Port EMCT CKT Overheat Yes Constant 6-100% Overheat condition, 212 degrees F (100 degrees C) limit Sea Pump PSI Lo Yes Constant 6-100% Low water pressure strategy, defaults to 43.4 psi Sea Pump CKT Hi Yes 2 Bp/min 90% Open Sea Pump CKT Lo Yes 2 Bp/min 90% Short STB EMCT CKT Hi Yes 2 Bp/min 90% Open, defaults to 32 degrees F (0 degrees C) STB EMCT CKT Lo Yes 2 Bp/min 90% Short, defaults to 32 degrees F (0 degrees C) STB EMCT CKT Overheat Yes Constant 6-100% Overheat condition, 212 degrees (100 degrees C) limit Steer CKT Hi Yes No No Open and short TPS1 CKT Hi Yes 2 Bp/min 90% Short, signal to 5v+, engine will not start. Refer to data monitor screen. TPS1 CKT Lo Yes 2 Bp/min 90% Open TPS 1 Range Hi Yes 2 Bp/min 90% Above 4.8v, 994 counts TPS 1 Range Lo Yes 2 Bp/min 90% Below 0.5v, 35 counts Trim CKT Hi Yes No No Short, high range, visual warning on SC1000 only. Trim CKT Lo Yes No No Open, low range, visual warning on SC1000 only. 5 VDC PWR Low Yes 2 Bp/min varies Short any 5v+ to ground NOTE: If any 5v sensor becomes shorted to ground the engine will not start. If the engine is operating when the short occurs the engine may stop operating and will not start.

Nope. Just don't try to install the heads that way. Each individual rocker gets adjusted at a different point in crankshaft rotation. You will want the spark plugs out during those adjustments too as it makes the engine easier to crank over by hand. Also, get a shop vac busy on that debris around the lifter valley, as you don't want that to end up down in the oil pan. Stuff the valley with clean rags when you are done, and before you begin to scrape the block deck gasket surfaces.W

Could be. It will be in the exact location as the plug on the other side, just above the oil pan rail at the lowest point of the block. Remove the connector, and screw out the sender if that's the case. W

Certainly some evidence of moisture in the crankcase so careful pressure testing and non-destructive testing will be needed to ensure you have a tight engine after the repair. Cylinder condition will be the key, as you are already having the heads done. Take your time, and follow the manual closely and with a little guidance, you will get her back as good as new. If it were me, I'd do your air test once again after the heads are on before you install the rocker arms, exhaust manifolds and intake manifold. Better to find an issue then and this way it's easy to see if your shop did the valve seats right. W

There is a drain on the starboard side also, so you just pulled those head bolts while that side of the engine was still full of water. Just get the heads off and blow, and dry the cylinder bores and coat with a product like CRC-5-56, or Msrine 6-56. Motor oil on a paper towel will work in a pinch. W

If the hold down bolt and retainer have been removed, then rotate the distributor body slightly counter clockwise and it should break free and you will be able to pull it out. I don't know what your fuel rail looks like but it sounds like you have that covered. Be gentle with the distributor as the body is plastic. You may wish to turn the engine back and forth by hand a little to see how many degrees of rotational travel you see before the distributor rotor reverses direction. That will be a good indication as to how much slop you have in your timing chain. W

Some people think cooler is better. Actually uniform temperature is what is needed. Marine engines never coast as they are constantly pushing water. Like a car climbing a mountain and never getting to the top. As a result, combustion chamber temperatures run really high and that's why a typical boat spark plug is specified in a lower heat range than it's automotive counterpart and the base line fuel curves are much richer. Also, cooling becomes critical as localized hot spots can develop if cooling water is restricted due to a blockage, of insufficient in the first place. That said, pushing too much cold water through the water jackets will cause localized cold zones and the uneven heat profile causes havoc with the expansion of the cast iron. Cylinders need to be round and clamping pressure of head bolts needs to be uniform. The previous owner of your ride may have had an overheating problem which he tried to fix by removing the stat. Or perhaps he was just looking to ease the winterization process, making the block easier to flush and fill with anti-freeze for seasonal lay-up. Either way, I'd get a thermostat back in the thing. Valve seats too can take a hit if the fuel is entering the cylinder is a semi-liquid state, as full vaporization is critical for proper combustion. Engines don't run on liquid fuel and heat is required for proper air/fuel atomization. W

What do you mean by times props? On a dual prop drive with twin 3 blade props, no two blades should pass under the cavitation plate at the same time. During installation, the front prop gets installed with the center-line of a blade at the 12:00 position. The rear prop gets installed with a single blade center-line pointing to 6:00. Not necessary on the 3 x 4 blade prop packages. They call it prop phasing and doing it correctly seems to help with reducing vibration in cornering, and I feel it helps to reduce prop blow-out in tight turns. Who know if it really eworks, but I feel that it does and it costs nothing to find out. W

Removing the stat on a raw water cooled engine is not a good idea as the cold sea water inrush creates cold zones in the cylinder heads. Hard on economy, head gaskets, valve seats, and in some cases drive-ability. W