Impeller sharpening

georgiaken · Post by **georgiaken** » 31 Jan 2011, 14:08

Lil' Blue Rude wrote:Sorry if I came across too harsh. Sometimes you have those days ya know.

No apologies necessary (but certainly appreciated). I didn't take your response as too harsh.

I figure, people are passionate about the things they care about and no one wants a fellow angler to be misinformed with BS.

So, I didn't take it badly at all...

It's actually good to know that I have some options...and I'll know what to do if I follow those instructions and end up with no juice out the bottom end.

Regarding speed and fuel economy, I tend to think along the lines of...if you want more speed (and your current rig is set up right), get a bigger motor. If you want better fuel economy, get a 4 stroke, one of the newer high tech 2 strokes or ease off the throttle. The little things we do to tweak stuff often works, but sometimes it's not worth the trouble...

Post by **fender66** » 31 Jan 2011, 14:19

Regarding speed and fuel economy, I tend to think along the lines of...if you want more speed (and your current rig is set up right), get a bigger motor. If you want better fuel economy, get a 4 stroke, one of the newer high tech 2 strokes or ease off the throttle. The little things we do to tweak stuff often works, but sometimes it's not worth the trouble...

I'm already running a 225 Merc.....no chance I'm getting anything bigger. It's bigger than I want already.

Very seldom do I run WOT unless I'm messing around on my way back in on the river. Most of the lakes that I fish freak when I show up with my rig anyway, so I go pretty easy on those. It just sucks gas....and I'm used to it I guess....and I'm blessed to have it! Besides...I want to go fish way before I want to go fast.

georgiaken · Post by **georgiaken** » 31 Jan 2011, 14:23

There might be some folks out there who know how to "tune" an outboard for max output and better fuel economy...I don't doubt that.

My truck gets better gas mileage now than it did "new" and it's 15 years old.

It was a matter of upgrading my spark wires to racing wires, upgrading my spark plugs, cleaning EVERYTHING (engine top end, throttle body, intake) and changing over some of the fluids to higher end stuff (like Royal Purple). I got another 3mpg out of it all...over the long haul, it's paid itself off.

If we have folks who know how to do that with outboards, I am all ears

optaylor823 · Post by **optaylor823** » 31 Jan 2011, 20:09

I agree with fender. I run a 175 and would love to see better gas mileage. It is hard to miss some of the rocks in the river I fish at 40 mph, so I usually don't run wide open. I may have missed this in the post, but I can say from experience that it does not matter how sharp you get the impeller if you do not shim it to the 1/32 gap.

moelkhuntr · Post by **moelkhuntr** » 31 Jan 2011, 20:16

Do they make any shims that are HALF the thickness or do you just shim it down where moving a shim to the top makes it hit. A person could get it down to the nitty gritty with shims half the thickness. Or, if a person is that dang close it's going to make that much difference.

optaylor823 · Post by **optaylor823** » 31 Jan 2011, 20:25

I shim it as close as I can get to 1/32 and not closer. The impeller will have some wobble in it, so if you get to close it will hit and you do not want that.

Post by **bulldog** » 31 Jan 2011, 21:17

I have heard of people grinding the shim washers down to half the thickness but it sure would be nice if they made them that thin.

Lil' Blue Rude · Post by **Lil' Blue Rude** » 31 Jan 2011, 23:31

Glad I didn't upset anyone, just read back over it and thought it could have been taken the wrong way.
Putting on exhaust,carbs(or re jeting carbs) and raising compression is the normal mod around here and most guys say they get better gas milage and perfomance from their set ups. It makes sense. If your boat runs better it's not laborig as hard so you don't use as much throttle getting around. Setting your boat up for speed is the best way to get better gas milage in my book, as long as you don't have a lead foot(or hand in this case)

You don't want to get your impeller shimed down to for because they do tend to wable a little.

Codeman · Post by **Codeman** » 02 Feb 2011, 21:49

I was going to pull my impeller and sharpen it before this weekend. I just checked, IT'S TOO FREAKIN' COLD OUT THERE. LOL Looks like it won't be coming apart before Saturday. She'll run what she runs. moelkhuntr if you are afraid of running way back of those big motors, just throttle back a bit and I'll catch up and keep you company. LOL

moelkhuntr · Post by **moelkhuntr** » 03 Feb 2011, 09:21

If the temp keeps dropping I may be running really slow as to not blow out the fire that I will have in a five gallon bucket to keep warm. HaHaHa. Started out to be 43 for Sat and it went down to 31 now it's up to 38 again I see. One thing about MO, give it five minutes and it will change for sure.

Codeman · Post by **Codeman** » 03 Feb 2011, 14:54

moelkhuntr wrote:One thing about MO, give it five minutes and it will change for sure.

No truer words have ever been spoken. LOL

Seth · Post by **Seth** » 19 Feb 2011, 23:13

Just tried to sharpen my impeller but dont think i accomplished much. Its a stainless and seemed way too hard to hand file anything off. I have some pics of it but havent got them off camera on to computer yet.Ro you guys use a hand file or something motorized?

Also have a question about tightening the impeller nut. Do I torque it down as much ass possible then back of so I can flip retaining tabs down OR do I tighten it and back of just a tad so it has a little bit of side to side motion? I didnt pay attention to how tight the nut was when I took it off.

Lil' Blue Rude · Post by **Lil' Blue Rude** » 20 Feb 2011, 00:15

I use a wrasp when I sharpen them, then I'll smooth them out with a flat file. When I tighten my nut back I get it as tight as I can. You can normally tell when it's getting snug, keep turning it until the tabs can lay flat on nut, just make sure you get those tabs folded down properly. It's a bad deal if they open back up.

$$$

Seth · Post by **Seth** » 20 Feb 2011, 00:32

What's a wrasp?

I think I better pull the grate and double check the tightness of that nut. I'm pretty sure I could have gotten it a bit tighter than I did.

blunt · Post by **blunt** » 20 Feb 2011, 09:05

a rasp looks like a file, but is much more aggressive and it's primarily made for shaping wood.