1956 Johnson 15hp Noise

[bjarnold]

I have a 1956 Johnson FD-10 15 horse outboard that has a whining sound when the engine is running. The faster the Rpm's the louder the whine. Is this normal? if not what could the problem be?<br /><br />Thanks

 

[R.Johnson]

Re: 1956 Johnson 15hp Noise

My guess would be that the whine is coming from the lower unit. I would check the gearcase for straightness. A bent gearcase will give that noise you discribe. .025 is the limit that in can be out of alignment

 

[umblecumbuz]

Re: 1956 Johnson 15hp Noise

Hi BM,<br /> <br />Increasing or excess whine spells possible trouble. Whine is inherent with all gearboxes, so - as RJ says - the initial odds are that it is coming from the lower unit. <br /><br />However, before running, why not walk a little - take time to narrow the odds. <br /><br />Is the motor new to you?<br />If not, has the whine recently developed?<br />Is there additional vibration along with it? A bent gearcase(!) will also vibrate, but so will a bent prop. Have you hit anything in the water lately?<br />Does it whine only when in gear?<br />If so - both forward and reverse, or one only?<br />Either way, have you verified the level and the condition of the lower unit oil?<br /><br />To pinopoint the noise, run the unit with muffs. <br />Put a metal rod to your ear and place the other end on different areas around the unit while it's running. You'll be amazed at what you'll hear and how accurately you'll locate it! (I have a special, hollow telescopic metal rod with an earphone on one end for this purpose.)<br /><br />Just a few suggestions - hope they help.<br /><br />Ciao.

 

[Chinewalker]

Re: 1956 Johnson 15hp Noise

Hi Bill,<br /> I'm with the other two guys - think lower unit. Your motor has bronze-phosphor bearings and when they start to wear - particularly the one under the pinion gear - the gears get out of alignment and the whine can get very loud indeed. Won't know until you take it apart... pretty easy to do on that motor.<br />- Scott

 

[bjarnold]

Re: 1956 Johnson 15hp Noise

The motor is new to me. There is no vibration and I have not had it out on the water yet. I had the prop shaft checked and it was bent .004. It whines in neutral,forward, and reverse. I am planning on using it next week. Will that damage anything?<br /><br />Thanks

 

[umblecumbuz]

Re: 1956 Johnson 15hp Noise

Presumably when you say bent,the shaft is out of true at its extremity. The propshaft has its own bearing housing, and there is usually a bit of play at the prop end of the shaft. Runout is not an easy thing to measure accurately without dissassembly - but if true, that amount should not be a problem.<br /><br />The driveshaft runs down through the lower unit, and it is revolving as long as the motor is running. At the lower end is a pinion gear, which meshes with forward or reverse gears on the propshaft. Above this gear is a bearing with upper and lower thrust washers. If it whines in neutral, it could be this assembly. It is more likely to be this than anything else, but try the 'ear' test I posted earlier.<br /><br />Have you checked the condition and level of the gearcase oil? Milky oil means water's getting in. If so, a strip-down's due. No milk? then why not renew the oil anyway?<br /><br />But I wouldn't like to state that it will definitely not give trouble - haven't heard the whine, have I?