it be done without running the

2021/05/21

Can it be done without running the engine? Few of these have thermostats so running them in gear at fast idle creates some engine load and heat to remove more crystals than if they were just idled in neutral. This is essential with carbie two-strokes as some of the air/fuel mix escapes with the burnt gases, and the better the scavenging the more efficient the combustion process. BF5. Evinrude, Mercury and Tohatsu have flushing attachments that create a backwash around the thermostats and flush out the cooling passages without needing to run the engine. stroke 15hp mercury outboard 1200 muskegon larger 15hp It's an idea but I'm still hoping for a solution with the hose that doesn't involve running the engine though. Extremely messy, but did the job. Our experiments in our wheelie bin suggest that we will end up with water everywhere if we try to do it in our boat's cockpit with a bucket; we don't want to have to remove the prop every time, we've abused the split pin enough replacing the impellor. An impossible dream? JavaScript is disabled.

Carbie two-stroke M2.5, M3.5A, M3.5B, M4 and M5B. Carbie two-stroke 1.5, Colt, Junior, 2.3 and 3.3, 4 and 5 (single-cylinder). However, with the two-strokes that dont have thermostats its better to run them in gear in a flushing drum to raise engine temperature and flush out those unwanted aluminium chloride crystals. To prevent the engine running too cold when trolling, the passages are smaller than theyd be were a thermostat fitted, and these small passages are more susceptible to clogging. Does anyone know of any sneaky diy or aftermarket method of flushing through with a hose that doesn't involve getting soaked? We had a hose attached to the threaded the coolant outflow, and had a 12 pump attached to the end of the hose. Drive home with petrol fumes because we didn't run the carb dry. Evinrude four-stroke 3.5, if not using the backwash attachment. Simply tape up the main intake, turn on the water and flush the engine for around 10 minutes. Thanks for the suggestions, I guess we will be using a bucket; But if anyone has come up with something cunning for the end of a hose, I'd love to know about it. Unfortunately, apart from some smaller Evinrude, Mercury and Tohatsu four-strokes this feature is mostly limited to larger outboards. Never run out of fuel while flushing a carbie two-stroke the lack of fuel also means no oil, so the bearings could be damaged and cylinder walls scuffed. Both DT5 models should be flushed in reverse at fast idle. Unfortunately no use to those with outboards without a gearbox but I have an interesting solution for those whose engines can run in neutral. Aground in Yorkshire awaiting a very high tide. Before flushing muffs became common when outboard manufacturers started locating cooling water intakes just above the gear case torpedo, the traditional way of flushing small outboards was to mount the outboard in a drum, then fill the drum with fresh water until the cooling water intake was well immersed. The 5 should be flushed in reverse at fast idle to load the engine but avoid ejecting water from the drum. A thermostat maintains running temperatures in a relatively narrow band so the cooling passages can be larger, allowing for a larger volume of water and more effective heat absorption from the cylinders. Think of the convenience: Quick hose of boat, fill up water tank, whack on attachment, five minutes up the outboard 'ole in situ on the pushpit and we'd be done without all that faffing and whirling of blades. In reality the crystals aint salt theyre aluminium chloride formed from the reaction between salt water and the aluminium passages. So with that lesson learned, the Tohatsu M8B Ive been testing for 12 years has always been flushed using muffs and its never had an overheating problem. But oh, how wrong I was! This alloy has a fairly rough surface that catches the crystals more easily. After they got fancy new plastic bins I took to running it on the pushpit with a bucket hung over the shaft, being fed with a hose. This clogging happens more rapidly in engines without a thermostat. Four-stroke MFS2.5 and MFS3.5 if not using the backwash attachment.

You should never run a larger carbie two-stroke outboard in a drum as the much greater quantity of oil these push out can quickly coat the cooling passages and lead to engine overheating as I found out with a Yamaha 15F I owned for eight years. Crystal accumulation not only depends on how hot the engine is running but also the type of alloy used in its construction. For a better experience, please enable JavaScript in your browser before proceeding. Fill wheelie bin with water via hose pipe. drag engine to car and cram in with all the other boat $h!t. However, Japanese outboards have traditionally used a high-copper alloy that is needed for easier pouring into sand castings. Cooling water in the cylinder block and head absorbs heat from the combustion process and mixes with gases in the exhaust system to cool them and help scavenge the exhaust system. You must log in or register to reply here. However, flushing is more effective if the engine has a thermostat, as running a non-thermostat engine under no load never removes all the crystals. Outboards such as Tohatsus, Japanese-built Mercurys from 15hp upwards and Suzukis from 25hp upwards have auxiliary cooling-water intakes that need to be taped up before attaching the muffs, otherwise the impellers will suck air, run dry and be ruined. Regular flushing helps keep the cooling water passages in top condition and reduces the possibility of your engine overheating. Way better to use a fuel stabiliser during flushing, such as Stabil or Evinrude/Johnson 2+4 Fuel Conditioner, and stop the engine before the carbie runs dry. It's our first outboard and in virtually new condition so we want to look after it proper, like . In fact Im still running the original water pump impeller, and cooling flow is as strong as it was when the engine was new. Tie a length of rope through each hole, tie that over the outboard or to the pushpit after slipping the fender over the outboard leg. Remove bit of shredded paper that blocks tell tale. We've just acquired a 1996 Mariner 2.5hp 2 stroke outboard for our tender. You may consistently get away with it but it remains an easily avoided risk. Hence the old adage that taking a US outboard for a long run would flush the cooling system, almost eliminating the need for regular freshwater flushing. So we are making our first forays into flushing. Drag down to pontoon from carpark How about getting a fishermans bait bucket. Carbie two-stroke DT2, DT2.2, DT3.5, DT4 and DT5 (single and twin-cylinder). Next weekend, cram outboard in car with all our other boat $h!t and find that not all the petrol has evaporated yet. The twin-cylinder Evinrude and Johnson 5 plus the 6, 8 and old above-prop exhaust 25 have special attachments that clip around the intake ahead of the exhaust outlet. This should be flushed in reverse at fast idle. The 4 and 5 should be flushed in reverse at fast idle. Cut the top off an old fender large enough to fit over the prop and cavitation plate. Controlling engine temperature is essential for efficient combustion and to meet emissions standards, which is why all water-cooled four-stroke outboards have thermostats. I have one. US-made outboards such as Mercury and Evinrude/Johnson use either die casting or lost-foam casting that enables extremely low-copper alloy to be used. Replace all recycling in bin. IMHO rather a dangerous method, even with the prop removed, an accident waiting to happen. we've abused the split pin enough replacing the impellor we don't put it in gear though, on the couple of occasions we've tried that, the buckets split - perhaps we need better quality buckets? The trouble is that when the engine is running at full load, such as at wide-open throttle, salt crystals separate from salt water and lodge in the cooling passages. I find at least 10min at fast idle is needed to open the thermostat and flush crystals from around it and the cooling passages. One boatyard (Evros in Leros) used to have metal bins which were just right for clamping the engine to. Not only does this save water and fuel but also avoids annoying your neighbours by running the engine late at night after a full days fishing. The M4 and M5B should be flushed in reverse at fast idle. The engine would then be run for five minutes in the belief the crystals would be flushed out. Struggle with wheelie bin to end of drive, to tip up and empty in gutter; hope it survives impact. The outboard is too old (we think) to have the thread so that a flushing attachment can be used. A smaller drum with overflowing water helps get rid of the oil and is really the only way of flushing outboards under 4hp. Install engine and flush, thus disturbing our neighbours quiet evening. Cut a couple of holes in the new rim, I found a large wad punch the best, about an inch diameter seems to work well. Fill with fresh water and run the engine, preferably with a hose pipe running throughout. 12 v pump in a bucket of water, engine rinsed. Change shoes and socks because I failed to jump the wave. The prop is so easy to remove and replace, I would advise never flushing it in a bucket or bin with the prop on. I could have used muffs but thought the drum would be better. Well, you could just take it home whenever you can and flush it properly. This alloy has a fine grain that doesnt snag the aluminium chloride crystals. Small four-stroke outboards use very little oil in comparison to carbie two-strokes so flushing in a drum is unlikely to give them the oil-coating issue. Rearrange bicycles and motorbikes in overcrowded garage so engine can be installed to drain on wobbly, seatless chair because we haven't a bracket for it yet. The same could not be said of Japanese engines where the cooling passages could clog up with crystals unless regularly flushed. See the full version of this review in Trade-A-Boat #495. Four-stroke F2.5 and F3.5, if not using the backwash attachment. Raw-water-cooled outboards are designed to run no hotter than about 65C to prevent the rapid accumulation of these crystals. These work well because only fresh water is pumped up the cooling passages unused oil runs straight out the exhaust passages. Empty recycling out of wheelie bin. Amongst others, Suzuki and Tohatsu single-cylinder two and four-stroke outboards have provision for screwing in an attachment that connects to a garden hose. The trouble with this technique for carbie two-strokes is that they dump excess oil into the water, which is pumped up the cooling passages where it coats the walls and bonds to the alloy particularly sand cast reducing the effectiveness of the cooling system. Ah yes. Carbie two-stroke Thruster, 2, 2.2, 2.5, 3.3, 4 and 5. Unfortunately, the Mariner/Mercury 2.5 2 stroke doesn't have gear lever.