Scrubbing or Rubbing Noise

[jfholijr]

As you all know I just got my merc 650 1975 3cylinder outboard motor running. I have not been able to put the motor on a boat or in a test tank yet to continue on with the final adjustments but I have been keeping it running from time to time to keep the carb work in good condition. After I shut it down then turn the flywheel by hand I hear something like a scrubbing or rubbing sound. Almost like the sound of a balloon when you twist it or rubb it with your hand. Does this make sense and is this normal?<br /><br />Also, I know I have not been able to do all the adjustments since I am unable to put the motor in water, do these motors tend to idle a little rough? It's not unbareable but I wish it would be smoother than it is.

 

[honda21]

Re: Scrubbing or Rubbing Noise

how are you running your engine, are you running it without any water at all, reply back to me and maybe i can help

 

[jfholijr]

Re: Scrubbing or Rubbing Noise

I definately make sure I'm using the muffs when I run the engine. I really don't want to destroy all the work that I've put into gettin this thing running.

 

[honda21]

Re: Scrubbing or Rubbing Noise

well the only thing i can think oif that would rub is the water pump impellor, and did you say your engine was idling rough? well the rubber sound should be the pump rubbing in the houseing, thats the only real thing i can think of

 

[jfholijr]

Re: Scrubbing or Rubbing Noise

Hmm didn't think of that. The impeller I replaced really does a good job of circulating the water. Strong stream out of tell-tail and from the vents on top of cavitation plate and out the props exaust. The second the motor starts the water is a pumping. Also even when water is circulating through the impeller it probabley still gets warm where the splines touch the housing causing a certain amount of friction that goes away when it cools off. Make sence?<br /><br />Yes it in my opinion idles a little rough? As of now I'm attributing the idling issue to the fact that the motor has not had all the proper adjusting because I've not been able to put it in the water to do them. But still don't these motors tend to idle a little rough anyway?

 

[quantumleap]

Re: Scrubbing or Rubbing Noise

If you haven't broke it in yet I agree, it's probably the impellor. I noticed mine squeaking bit when I turned my flywheel by hand right after I rebuilt the water pump.

 

[Trent]

Re: Scrubbing or Rubbing Noise

Those engines do run a little rough on the muffs because of no backpressure on the exhaust system. Thats why you have to warm them up in the water and adjust in foward gear the idle speed and mixture.

 

[Virago85]

Re: Scrubbing or Rubbing Noise

may sound stupid and be way off but id check to see if the starter is disingaging had it happen to me once and sounded bad

 

[jfholijr]

Re: Scrubbing or Rubbing Noise

Thanks for all the responses. Yeah I'm fairly sure its the new impeller. <br /><br />No my starter is disingaging. Thanks to all.

 

[rocky25]

Re: Scrubbing or Rubbing Noise

i agree with trent, a two stroke runs with so much pressure, it has to be muffled properly to run smoothly, drop it in to forward gear, and make any necessary idle adjustments on your carb.

 

[jfholijr]

Re: Scrubbing or Rubbing Noise

so how do you adjust two carbs idle mixtures? The manual (seloc) says nothing on how to do two and my motor has two.