1954 Evinrude 7.5 hp noise

[steam_mill]

I have the above engine and it runs well. It is noisey. I've tried everything to silence it but no luck.<br /><br />The noise comes from the cowl. I've tried everything to stop the vibration but the motor at WOT sounds like a rock in a tin can!<br /><br />A couple of questions:<br /><br />1. On the fixed side of the cowl, the two attachment points to the cowl do not have a rubber bushing. Should the be a bushing here?<br /><br />2. The two bushings on the hinged side of the cowl are worn. I've 'manufactured' two bushings from the old bushings and duct tape. Is there anywhere that sells replacements?<br /><br />3. I think that the noise comes from the centre bushing where it rests on the motor itself. But the bushing seems fine. Comments?<br /><br />4. Another possible area for the noise is the actual hinge. Any ideas to silence the hinge if this is the problem?<br /><br />Tx.<br /><br />Joe

 

[petrolhead]

Re: 1954 Evinrude 7.5 hp noise

I moulded new rubbers for mine from RTV polyurethane rubber, using the one remaining original rubber as a pattern. I occurred to me that short lengths of rubber fuel hose might work just as well?<br />Another source of rattle might be the cowl to lower pan, there should be a rubber sealing strip around the top edge of the pan to stop metal to metal contact. I found a suitable replacement at an auto accessory store.

 

[Chinewalker]

Re: 1954 Evinrude 7.5 hp noise

Hi Steam Mill,<br /> The '54 model only had the metal spring clips on the fastened side - no rubber insulators. It's not going to hurt anything if you slide a strip of inner tube rubber between the cowling and the spring clip to help quiet things a bit. I've also found that much of the vibration actually comes from the seam between the cowling halves. This could mean that the snap clips that keep is shut have loosened up a bit or that the cowling has been bent at some point. In either case you should be able to put a strip of rubber or felt between the seams to keep the rattle down to a dull roar.<br /> Also, those motors run quite smoothly and if the rattle is a constant annoyance at all speeds, it may indicate a slightly imbalanced propeller or bent propshaft creating weird harmonics in the motor. Just something to look at...<br />- Scott

 

[steam_mill]

Re: 1954 Evinrude 7.5 hp noise

I think the vibration is in between the cowling halves. <br /><br />The engine actually runs quite smoothly if I hold down the cowl. There is no vibration out of the tiller. Although I don't disagree that there could be some other vibration issues, I'll ignore these. The engine runs well but with a leaking LU combined with a hissing pressure tank I'm running this engine 'till it dies and then try a more recent vintage (Maybe 1969?) 8 hp 'rude or Merc.<br /><br />I'm not prepared to throw money at this motor.<br /><br />I will buy the cowling halves though. They do look quite crooked....<br /><br />I'll keep you all updated....<br /><br />Joe