Proper setback and balance also helps. Prop Walk - Expert on Board Tom Cunliffe demonstrates how to find out which way your prop kicks. So, I limped home to port and docked up and ripped the prop off at the dock. The most cause of this on MerCruiser Pre-Alpha, Alpha One, Generation II and sometimes on Bravo outdrives are as follows : 1st - A spun hub inside of the propeller. Before you go to the trouble of measuring the pitch, look at the prop carefully and you will likely find the diameter and pitch numbers if it is an OEM prop. If the prop is moving forward or aft on the shaft then something is wrong there too. Just a thought. No go. Then have an authorized Mercury dealer diagnose the problem by inspecting the prop and, if the failure seems to be heat-related, checking the engine for other issues. I spun a hub at 30 hours. I have a 1995 17' cobia bay boat with a 2000 df70. Either the prop to pad is too high causing the prop to lose grip or if its a high performance rig getting into the mid to upper 80 mph range then blow out which if you've never experienced can be quite the thrill. The hub might be twisted or even look melted. When the propeller is forced to abruptly stop in a collision, the first thing to be sacrificed is the rubber hub. Trending; Popular; . If borrowing a prop is a problem, paint a strip inside the hub. The proper method is to remove the prop nut and using a magic marker, mark a line on the hub that runs/aligns into the propeller. No sign of anything. On aftermarket propellers, we must use the aftermarket HMS VS-14 or VS-45 hub, which has proven to be unreliable due to the horsepower and heat generated by the new fuel . If you remove the prop, it is usually apparent. Wylie ,Texas. Anyway, I pulled it off and the hub, too.and both look good to my eye. It may need replacing. You will likely feel the prop slipping at high RPM. No 'dinks' on the prop, no ropes hanging therefrom. New prop with new hub. Most liklely and it's fairly common,especially on cheaper aluminum props,is that the hub inside the prop is just slightly crooked, damaged or defective,causing the prop to not spin true. Hit it hard coming up on plane if the hub slips at all it will be obvious by looking at the mark. Posts: 482. Generated cavitations 2.) . Second is I'd contact the manufacturer of the hubs you been spinning. Now, remove the prop nut again and inspect that line you made. 09-10-2021, 08:28 PM. The Usual Causes of the Rubber Hub Detaching. too little clearance between the prop and the hull or skeg. Does your boat prop have a spun hub?This is a problem every boat owner should know how to fix and the good news is that it's much easier to fix than you migh. I'll throw my vote in on a spun prop also, if you have a spare try it out, if it works okay then you know what your problem is., If you don't have a spare yo should get one, having a spare prop on board and prop wrench can really save a day if you ever spin one or wreck one. Once the lower unit is off, put the boats shift linkage into forward gear by pushing the shifter lever all the way forward. Between $40-$75 here in TX. New hub in old prop -- same thing. The hub is a piece of plastic designed to break if you hit something with your propit's a safety feature so that none of the more expensive parts break. Since the rubber hub is responsible for a spun propeller, it is . You can detect a spun hub just by looking for circular scratches on the portion of the hub that bears against the thrust washer. So spinning a hub means your prop hit something and the shaft kept spinning breaking it's "teeth . It causes the outer surface of the prop to scrub a bit against the inner surface of the lower unit housing. Bournemouth. Not saying they did not somehow cause the issue but it's highly unlikely, especially when they tweaked one of their own props. Nothing. A spun hub feels like a loss of power with excessive RPM. The usual causes of the detachment of the rubber hub are the following: The violent strike of the propeller. Depending on the situation, if the line didn't get behind the prop, just cut the line and pull it off the prop. I'd first verify the correct hub is installed. Use the motor and then check the alignment of the line. Remove the propeller and examine the prop hub. Just me on the boat today with approximately 15 gallons of gas and 75 lbs of gear, it runs WOT at 54-5500 rpm's and 31-32 MPH. Seems like spun hub on volvo penta. In other words, Spun hub usually pulls good to a certain point, and the motor acts as it goes out of gear, the rpm . It is reverse threaded such that a load on the impeller with the motor turning will cause the prop to tighten itself. Water stream based on a propeller. in minutes. incorrect pitch. If you notice a crack, replace just that part. What Causes a Spun Prop? I trimmed it all the way down when I went out last night, it slipped or ventilated alot less. I replaced the old prop with a new, or maybe it is a rebuilt, I'm not . The good news is that it's much easier to fix than you might think, and in this . A violent strike of the propeller with a fixed object. Go to a dealer and borrowing a test prop, problem solved if you spun a hub. Once a hub is spun, there generally remains enough friction to operate at low RPMa "get home" mode of sorts. What Causes a Spun Prop? Expert Answers: A spun propeller means that the prop hub has spun inside the propeller. The instant diagnosis is "bu99er I must have hit something and spun the propeller hub". But, when RPM is increased, the engine revs with little or no boat acceleration because the prop begins to spin. Then have an authorized Mercury dealer diagnose the problem by inspecting the prop and, if the failure seems to be heat-related, checking the engine for other issues. What Causes a Spun Prop? Loose Nut: Sometimes you get lucky, and all that is wrong is that the prop nut has come loose. Figure out if you have a spun hub by marking the boat propeller and its hub with lipstick.Kevin Falvey What Causes a Spun Prop?. reef while it is functioning in many turns, the first thing to be worn out is its rubber hub. You can also score your mark using a file. Edit: over trimming can cause it as well. 3. Then take it to a mechanic to Check the power trim unit. Tom W Clark. You will likely feel the prop slipping at high RPM. posted 06-18-2008 12:39 AM ET (US) Hot exhaust gases is a very commonly reported cause of a spun prop, especially the Mercury Flo-Torq hub which use a plastic (DuPont Delrin) hub insert, which seems to turn brittle and fractures. Turn 5.) Apr 22, 2013. For Yamaha-made propellers, the best option is the original OEM 61A-style hub, which is now available. what causes a spun hub on an outboard motor. After that is done, set the lower unit into forward gear by turning the shift shaft in the front of the lower unit clockwise while also turning the propeller counter clockwise at the same time. first, YES, the older style rubber hub Suzuki props had a bad issue with spinning hubs. If you are experiencing propeller cavitation, please seek professional . They were fine for a lot of years, but for some reason, they had a lot of issues with them the last couple years they made them. The rubber inner bushing inside an outboard propeller hub is designed to absorb the shock created by shifting . If it is just grey powder, ignore it. Just an FYI, spinning props on the 300's is a known issue. August 18, 2011 at 7:33 pm #1273502. Re: yamaha spun prop [ Re: tds ] #14033970 06/16/21 05:02 PM. The engine could be down on power for some reason, or there could be an issue with. #3. #4. Once the hub spins inside of the propeller, the propeller will spin freely and not along with the hub. Since there are so many possible causes, diagnosing the problem should really be done on a per-case basis. There are ways to diagnose it. RENEGADE TACKLE - OWN THE BATTLE! If your boat motor is running and in gear, but your prop isn't spinning, then you might have a spun hub. You'll likely want to take it to a marine mechanic . A spun hub feels like a loss of power with excessive RPM. Your problem sounds typical of a spun hub. Strange clanking noises. But also, it's funny, you know, when you throttle and hammer down like that, that bow goes way up. First of all, it's less pressure on the hub. I took the prop home and put it on my spare outdrive, locked the drive shaft and tried to spin the prop. The rubber hub bushing also serves as a "breakaway" should you strike something, allowing the prop to spin, and so protecting drive train components like gears. Never a good sign. The rubber inner bushing inside an outboard propeller hub is designed to absorb the shock created by shifting. Marking A Prop To Show If It Has Spun Its Hub. Watch this short video to find out how to check. If it has, you have spun a hub. physical damage to the boat propeller or lower unit or bottom of vessel. The plastic hub is replaceable and cheap compared to a lower unit. I carry spare props because of this. It is not TBX hub system. I spun a couple of props with a slightly bent shaft and I could not get much beyond idle before it started spinning. These props are mounted on splined shaft so there is not sheer pin. same thing. When the propeller is forced to abruptly stop in a collision with e.g. That does two things. Lots of factors cause prop slip, but the best way to reduce it is to get a more efficient hull. . Sounds simple enough, but there are many variations for each engine/hp/prop/prop shaft. Take this and sort of mash the stuff between your fingers. The prop threads onto the driveshaft. Sometimes the hub will slip inside of the propeller at higher rpm's. The quickest way to check a bad hub is to try another propeller to see if it slips at the same rpm's or you can . 1. water in the gearcase lube. #4. Look at the aluminum casting on the end of the prop around the edge of the brass hub. Bad news is, when you have a new hub pressed in, you will likely spin it again very soon. It wasn't constant, the effect would come and go but was very noticeable. If the rubber is compromised in the prop hub - see if you can spin it by hand while it is in gear(not running of-course and plug wires disconnected). Tweet. A small boat may have a direct-acting lever like a motor car, but a hydraulic link allows the control lever to be fitted at some more remote point in a larger boat. To see if the whole issue all long has been user error, lower the jack plate and/or trim down a bit and see if the issue goes away. Once the hub spins inside of the propeller, the propeller will spin freely and not. 1.) At WOT 4200RPM, rpm go up speed falls off. A spun propeller hub will not plane your boat. Is my prop hub spun? What does a spun prop feel like? A spun hub feels like a loss of power with excessive RPM. My Friend with the same engine spun a hub 3 months before. The rubber hub bushing also serves as a "breakaway" should you strike something, allowing the prop to spin, and so protecting drive train components like gears. Drizly Delivery Driver App, Capital Chemist Breast Pump Hire, Cities With Most Construction 2020, Volvo D11 Engine Torque Specs, Titanic: Adventure Out Of Time Blackjack, Is Research America Legitimate, Best Magnetic Loop Antenna, Apartments For Rent Woodman Ave, Titanic Funnel Lights, Best Character Introductions In Books, Wgbh Telephone Number, 2. metal particles on the lower magnetic gearcase drain screw magnet. Ship's driving direction 6.) A spun propeller means that the prop hub has spun inside the propeller. Cavitations vanish away from propeller 4.) Not enough speed to hold the bow up, prop looses bite and slips. The symptoms just don't match a spun hub. If your engine can't plane the boat, don't automatically assume the problem is a spun hub. However there are times when the exhaust runs too hot and overheats the hub. If your engine can't plane the boat, don't automatically assume the problem is a spun hub. Rubber hubs cannot take the higher exhaust heat. But, when you increase RPM, the engine revs with little or no acceleration because the prop begins to spin. Cavitation and ventilation can significantly damage moving parts and are usually undesirable . The prop a Ballistic 14 1/4 by 19p SS was removed from old motor and installed on the 2007, I am pretty sure it was in the second year of use that on a long run heavy loaded was the first time the prop spun on the hub, the prop was sent out for a re-hub to a local shop and performed well for the rest of the year. The Raker II here was proved to not be an acceptable replacement for the original Raker. Next thing you do and you're pushing a bunch of water in front of you, and it takes more effort and time to get up on plane. Jul 14, 2011. Re: What causes a spun prop hub? Hitting something with the prop will do it too. Pein a dot on the metal splined hub and adjacent on the mating surface of the propeller proper. Prop hub is the simplest thing to check. (You will see damage from inside prop hub) While the prop is still mounted, the test is to put on some gloves and turn the prop against the lock, whether in forward or reverse. Felt like the shaft was free spinning. Location. Meaning, the anti-VENTILATION plate is no longer doing it's job. . Felt like a spun hub: I would throttle up with sluggish response from the prop. Verified there is no water in the power trim hydraulics (this would cause the motor to lose trim functionality). If the hub slips before turning the . Sometimes, the hub only spins when the engine revs above a certain RPM, causing many boaters to wonder if they have spun a hub, are experiencing ventilation or cavitation, or have some kind of gear or power issue with their outboard. The prop shaft surface where the thrust plate seats or meets the tapered surface on the shaft look pitted and scratched. Because the rubber hub is responsible for a spun propeller, it understandable that some would ask why single-piece propellers . #3. Like Robby said high torque and hitting objects are the usual suspects. To tell if your hub has spun, mark a line on the back of the prop hub with lipstick. Make a mark or check the alignment of the prop to the nut or pin (take a photo as well for reference).. Before my next trip I will mark the hub and see if it spins. Cavitations coved backside of the propeller 3.) Louie and his family have been making props for ships and boats longer than we've been alive. A picture is in this case truly worth a thousand words, so if possible post some pics of the prop and the mounting height on the boat from an angle the relationship between the bottom and the engine gearcase can easily be seen. Strike a line with a permanent black marker or grease pencil across the rubber hub up to the prop. Now replace the prop nut etc and test run the rig so that you encounter the problem. Set the new prop hub in place, slide the prop on, and tighten the prop nut. 3855 Osage Lane. The splines on the shaft keep the thrust washer from slipping, so if the propeller has a spun hub it will become scratched as it rotates in relation to the thrust washer. With the mark in place over the inner and outer hub, it's a simple matter to pull the prop and see if the mark has broken in two. If you happen to hit something with the prop.lightly, it's job is let the shaft spin when the prop stops on a object, so that the lower unit's gear don't take the blunt of the hit. Hughes Marine. If the line is now broken, the prop obviously slipped on the hub. Planes out great. Verify with them you're using the correct hub per engine/prop specs. Perhaps there was a recall on that hub. But, when RPM is increased, the engine revs with little or no boat acceleration because the prop begins to spin. There may be numerous causes of propeller cavitation such as: incorrect matching of propeller style to the boat application. I am thinking clutch is going. I back it off and it's ok and at full bore it will over rev again.I know it sounds just like a spun prop would act, as I have had this on another motor. The engine wants to scream and spped dies. spinning props. What causes a prop hub to spin? Please visit us at https://www.propshopinc.com. A spun propeller means that the prop hub has spun inside the propeller. Then try and pull the line out while spinning the prop to unravel the line. Another method is to use a ball pein hammer and a center punch. Been thinking about a new prop anyways. This drawing shows where cavitation can occur. You may see numbers in this format: "10 1/2 x 13" which is the diameter and pitch. The way I check for spun hub is to scratch a mark across the back of the prop and the hub. The time I spun a hub, it acted funny a couple of trips and then it was obvious it was slipping by looking at mark. Come out of hole great. Johnson outboard sometimes starts to over rev when on full throttle. The go out and get it to "spin" as you experienced.. Then come back and see if the marks still line up or if they have moved.. 9 Jun 2013. It will no longer be a straight line. Run the engine under load. If you can feel metal particles, it is cause for concern. No noise no vibration. Control Astern - Expert on Board . The anti-vent plate should, at most, be skimming just along the surface at full speed/plane. I have never encountered a prop unthreading itself, but that seems to be what has happened. I doubt a slipping hub even though the prop does have a rubber hub. The engine could be down on power for some reason, or there could be an issue with . Once the hub spins inside of the propeller, the propeller will spin freely (slowly) and not along with the hub. If it did get behind the prop, turn the engine off, take the key out, and trim it out of the water as we talked about for the rope. All Raker props moved to the TBX hub back in 2006 and were named Raker II. A spun hub feels like a loss of power with excessive RPM. This not only causes the motor to rev easily, but it reduces the thrust provided by the propeller, slowing the boat's speed and/or acceleration, as well as reducing the propeller's control over the boat (blow out on turning, on hole-shot, etc.).