Neptune mighty mite 1.7 hp

[kpimpz]

How much oil do I mix with 2 gallons of gas and is the exhaust pipe supposed to get really hot do I need to clean out the impeller tubes can they get clogged / why can I not throttle down to low it shuts off on me I can keep it running high but when I throttle down to low it just shuts off any pointers or tips

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[frankr]

Loud? Is the exhaust tube there? Any big holes in it? There should be two big tubes, one the steering swivels on, and the exhaust tube aft of that.

There should also be two small tubes for the cooling water. One carries water up from the pump to the powerhead, and after the water does its job of cooling the powerhead, it returns to the lake through the second tube. No, it should not escape anywhere along the way. That is a siphon system, with the weight of the down water equaling the weight of the up water. Make a hole in it and you break the siphon.

[kpimpz]

All seems good I can’t post pic does anybody know what adjustments I can make to make it quieter like I don’t know what the screws do like the the little needle valves

[kpimpz]

OK here’s one when I run it out of water in a bucket it works fine as soon as I put it in the water to go fishing it won’t start something about the pressure in the carburetor I’m not sure how to fix it any suggestions thank you

[garry-in-michigan]

A two cycle engine without a super charger is essentially a two sided piston pump. As the piston goes up on the compression stroke, the back of the piston is drawing a fuel-air mix in through the carburetor. As the piston goes down on the power stroke, the back of the piston is increasing pressure in the crankcase. The exhaust ports open first to relieve pressure and get the products of combustion moving in the right direction. When the transfer ports (AKA – bypass ports) open the pressure in the crankcase should be equal to or greater than the pressure in the combustion chamber. What could possibly go wrong? Unfortunately, many things. If the piston skirt is worn, crankcase pressure can leak out the exhaust. If the piston rings are stuck, compression (and efficiency ) will be lower and the crankcase charge will be contaminated. The underwater exhaust compounds this by increasing exhaust pressure to displace water. The loose bearings of a worn out motor also leaks away crankcase pressure. Many drill holes in the exhaust pipe to lessen pressure, but may not help enough on a worn motor and significantly increases noise. Small pistons are very sensitive to piston ware. Sometimes switching to a SAE 40 weight oil will help. TCW-3 oil is a disaster in these old motors. It lubricates well, but does not seal a loose bronze bushing. A border line outboard may produce enough power to keep running with no load, but anything that uses power (displacing water or turning a propeller) takes away the power to keep the engine running. . . 🙄

[frankr]

Garry just explained just what I was thinking. Long story short, a motor that will run out of the water but not in the water is a classic example of a worn-out motor. A nasty way of saying a motor that doesn’t have enough power to move the water. But don’t give up yet. Check the reeds.

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