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Now look at your rpm- it should be in the top half of the mfrs recommended top end rpm. The 15 might lower your rpm a little but remember the real target rpm you should shoot for is peak horsepower.
I recommend adding up to 2 inches to the outboard motor shaft length to be on the safe side see height diagram.
Proper outboard motor mounting height. Other factors to consider when determining the mounting height of an outboard are related to performance. However the motor should not be raised more than 5 inches above the standard position. What is the correct height to mount an outboard motor.
For a propeller to best satisfy particular boating needs the engine must be attached to the transom at the correct height. Over the past 30 years industry standards for transom height have been developed. 15 for short shaft engines 20 for long shaft engines and 25 for extra-long shaft engines.
Turns out some boat builders are letting transom height get closer to 21 inches or 26 inches. Adjusting the mounting height of an outboard on the boat transom can affect performance and every boat can be different so actual on-water testing is best. There also can be significant imprecision on fiberglass boats.
Mounting height - cav plate anywhere from even with hull bottom to about 2 -3 above. Porpoising - in some cases trim tabs the best and final solution plus you get the added benefits of controling how your boat rides through chop. Now look at your rpm- it should be in the top half of the mfrs recommended top end rpm.
For example the Verados range is 5800-6400 rpm. Therefore I should be at least 6100 6250 would be ideal. But dont get hung up here anything over 5900 rpm is ok you wont be hurting the motor.
If the 1 lift rule to 12 set back holds true SIC than my engine should be mounted 5 ft above the transom not 5 inches. And if the 1 lift to 12 setback holds true you would only mount your engine 5 FEET above the transom if you could set it back 60 FEET from the transom. Now that your motor height sounds right you could see if some your buddies have any stainless props that would work on your boat.
A 13-15 stainless should work fine. The 15 might lower your rpm a little but remember the real target rpm you should shoot for is peak horsepower. Refer to Determining Recommended Outboard Motor Mounting Height preceding and Install outboard to the nearest recommended mounting height.
Fasten outboard with provided mounting hardware shown. C b a b c a d a-12 In. Diameter Bolts 4 b-Flat Washers 4 c-Locknuts 4 d-Marine Sealer - Apply to Shanks of Bolts Not Threads.
Trim the motor down so it is vertical. Place a block of heavy wood under the outboard skeg so it is an inch or so below the skeg. You might need to use some bricks etc to get it to that height just make sure they are very stable as they will need to take the weight of the outboard and be stable.
Ive been having a good old time playing with engine height trim using the Porta hydraulic motor bracket on my LaConner as it will raise or lower the engine 17 vertically. Ive found that ideal motor height is a variable depending on sea conditions how a boat is loaded what your HP to weight ratio is what type and pitch prop you have and what speed you want to run at. EOutboard mounting height height of outboard transom brackets from bottom of boat transom.
For heights over 22-inches 560 mm a propeller that is specifically designed for surfacing operation such as a Chopper series is usually preferred. There is a simple test to see if your outboard motor is set at the best height. Simply start with the engine in idle followed by trimming the motor out by one-half to full trim.
Safely but briskly accelerate. If the propeller fails to ventilate the motor is mounted to low. There are instances where a lower mount may be okay.
Arrowmarine Senior Member. I want to say that we always put them with the leading edge about 14 above bottom of hull. Dont quote me tho.
Arrowmarine Apr 16 2005. The transom height needs to suit the outboard and ensure that the propeller will be in the correct depth of water in relation to the bottom of the boats keel. The height of the transom needs to let the cavitation plate just above the propeller sit below the bottom of the keel.
About 25 mm or so below the keel is usually about right but you might need to seek advice on this as the shape. Heres how to make sure that your outboard is at the correct height by using your anti-cavitation plate as a guide. Find a straight edge that is around 8 to 10 long.
A long 24 is perfect for the job. Trim your outboard down and into the proper position. Proper outboard height The diagram above is agood starting point but you will likely need to go up a little higher than that.
If the engine is mounted directly to the transom and there is no notch running surface of hull runs all the way back to the transom then you will need to mount he engine with the anti-ventilation plate sometimes called a cavitation plate a little above the running. I recommend adding up to 2 inches to the outboard motor shaft length to be on the safe side see height diagram. So for example if your small fishing boat has a height of 15 inches in the back you would want to choose an outboard motor with a shaft length of 15-17 inches.
When they remounted the engine the mechanic said on most all pontoons the cavitation plate should be about 1 inch below the bottom of the tubes. Originally mine was mounted in the second hole from the top and he changed it to the top hole to lower the engine about 1 inch. Sometimes high-strength sealants also cause height fluctuation for a mounted outboard.
The outboards have mounting holes that are vertically aligned. After attachment the outboard may look like its dangling. This suggests problematic adjustment.
The comparative size of the gear case for a new engine may require a change of height. Need some help with my outboard jet Mounting height Spray Post by dhoganjr 09 Jul 2014 2227 That is what we did originally with the 115 the dealer had it mounted too low. A long shaft engine requires a height of 20 and extra-long shaft engines will need a transom height of 25.
While this is the case there is certain saltwater motors that are extra extra long at 30Keep these numbers in mind if you ever have a need for a new outboard motor for your boatMounting the outboard motor in accordance with the.