Motor height / Losing power

[tmcalavy]

Re: Motor height / Losing power

If you didn't improve things by moving weight around in the boat and the trim pin is all the way out, you've got a major hook in the hull. Bummer, but it's just another adventure for you to tackle...you're up to it.

 

[jbjennings]

Re: Motor height / Losing power

Well you bunch of NAYSAYERS!!!!! I assume you could use some panelling and tape it around the powerhead in certain areas so it wouldn't squeeze in amongst the linkages and other stuff before you put the bag around it for extra protection, and also wouldn't be so tight a fit that it wouldn't allow any air flow. After all now guys, it is a WATER cooled motor! Anyway, I'm blaming the whole thing on that rotten WBeaton for bringing up the garbage bag thing. I also think you could take the cowl off and trim the foam as needed and then put some kind of sealer on the foam to keep it from breaking up. Where there's a willl there's a way.
As to STEVE's question, I like the sound of the bigtwin, but like you I also like a quiet motor--but don't tell anyone. I once put dual exhaust with mufflers on a used pickup I bought and put a crate motor in and it drove me NUTS---well, even more nuts. So yes, I would like it quieter for sure! I am going to figure out a way to make it quieter, though. I just haven't gotten around to that part yet!
I believe it's probably an "old fart's tale" rather than an "old wives tale" this time!
Later,
JBJ

 

[wbeaton]

Re: Motor height / Losing power

Well you bunch of NAYSAYERS!!!!!

I have to agree with, JBJ, here. Obviously the powerhead and linkage must be wrapped so that foam can't get in around the linkage and carb. Some would probably need to be trimmed back after spraying. Like around the exhaust for instance. However, anyone that is handy enough to work on one of these old motors is surely handy enough to figure out some methods for sound deadening.

 

[samo_ott]

Re: Motor height / Losing power

ok, if we're gonna get down to the details here... there's usually only holes in the front of the cowling, how would one get the foam anywhere on the back other then down low along the bottom? And each type of engine would be different. Any engine with a bottom cowling would be difficult to get in. And the foam would have to be vertically consistent in thickness as if the bottom was thicker than the top the cowling will not come off (on the non clamshell type cowlings). How would you control that? I do not see this as being an easy job.

If you want to do some modifications the one I have always wondered about is how can the intake manifold be modified so that instead of dumping the excess bled off fuel into the exhaust system it could it be captured and recycled into the fuel system. That would save a lot of fuel and pollution by the oldies at lower speeds.

 

[jbjennings]

Re: Motor height / Losing power

Alright Steve,
You've got a point, it would be pretty tough! But I still think I'm going to give it a shot in some form or another. BTW, I thought it was just the smaller engines that had the overboard dump and not the 10's, 18's, and 25's. Is that totally wrong?
Also, is it a hook problem on the boat?
Later,
JBJ

 

[samo_ott]

Re: Motor height / Losing power

Just make sure you take photos so that when you're scraping out spray foam from the carb throat and pull starter springs you can post em and we can all see what NOT to do!

And I believe they all dump excess fuel at low speeds. That's the nature of a 2 stroke.

 

[The-Machinist]

Re: Motor height / Losing power

I lined the cover on my 57 evinrude 35hp with Dynamat. Its self adhesive, about 1/2" thick, and is available at any autosound store. My motor is almost too quiet, I am thinking about cutting a small square of mat out in the front so I can hear whats going on back there

 

[samo_ott]

Re: Motor height / Losing power

Cool. Never heard of the stuff but it sure sounds a lot easier than spray foam! what's it normally used for?

 

[wbeaton]

Re: Motor height / Losing power

I'm talking about a 1954 Big Tiwn. There is no lower cowl pan or seal. Also, the cowl separates from each side in two separte pieces, unlike a clamshell so taking the cowl off would be no problem. Access can be obtained from under the cowl or from the rear spark plug hatch. The foam doesn't have to be uniform in thickness to insulate the cowl. There is no reason for the foam to get into the carb and linkage. That's why you wrap the powerhead in a heavy plastic bag or the like. Either way, its been done before with no ill effects.