Impeller tolerance

[smackdaddy53]

Jetboater-
I read all that, I researched just about every website, forum etc trying to learn about what I was getting into. I understand there is play before the shaft/bearing housing is bolted up. My issue is after being bolted up I still have a little play in the shaft. I have a new sleeve and key so it is not that. If this is one of those issues I just can't fix I may just sell the jet pump and go with a prop unit.
Dhogan-
Yes it is frustrating but I will give it some time. Reading and real world experience are very different as many of us know! I am going to get after it more tomorrow and get it in the water to figure this out.

 

[dhoganjr]

I would suggest giving Troutt & Sons a call, ask for Chris in the service dept. Tell him what is going on, he should be able to get you going. With that much play I think it is something more than I can help with at this point. https://www.trouttandsons.com

 

[Jetboater-TB]

Does the motor push you along OK? If it runs OK, I wouldn't worry about it. A little contact is not a fatal flaw. I've heard some guys even install it so the impeller touches the liner, and let it wear in, especially with a stainless impeller.

Another thought is that the impeller nut could be loose, letting the impeller wobble around at start-up and shut-down. When its running, the up-thrust holds it in place.

That could explain your loose aluminum shavings. They could have happened on shut-down if the impeller was wobbling. Hard to imaging the shavings not getting blown out of the pump if they happened while it was running. Are you sure the play in the shaft that you're seeing isn't mostly play between the impeller and the shaft? You could try to get a thin feeler gage under the nut.

 

[smackdaddy53]

I ran it today a little and it was fine other than needing to be tucked under more. I have the motor set on the last hole tucked under as far as it goes and it definitely does not ride bow high like it did on the runs right before where I had the motor trimmed up two pegs higher. I bought some aluminum transom wedges to get the jet pointing a little more down and I will be installing them tomorrow.
I still feel like the motor is not enough to really jump up like I keep hearing other guys talk about. It is hard to believe guys on here stating they run 50/35 jets on boats as big or bigger than mine with two or three guys and gear and they are getting 25-30mph. I am going to play with settings until I am either happy or I will end up selling this motor and getting a 90 merc jet or just say screw it and get a prop unit for it. I really expected this boat to be more lively.

 

[Jetboater-TB]

I haven't seen a description of your boat and layout. Would like to see your boat specs and the performance you're seeing. Here is what mine looks like for comparison.

I ran a 40/30 Merc on my Roughneck 1655 tunnel hull for almost 20 years. Best it would do is about 24 MPH, but it would jump on plane right now. It was underpowered, but worked just fine. Just upgraded to a 60/45 Merc, and now it goes a little better than 29 MPH tops, downhill through shallow rapids. I have the front of the intake foot about even with the top of the tunnel, so the whole jet nozzle is out of the water, and the whole foot is above the bottom of the hull. I can't run the motor with someone standing on the front deck, because it will lift the whole intake foot out of the water. When I hit something, I hit it with the hull. (If you're not hitting stuff, you're reading the wrong forum.)

The 60/45 gets to top speed quicker now, and will cruise at 24 MPH easy at about 2/3 throttle. The new motor has a 3 blade Stainless impeller. I think any faster than 29 on my home waters, and you're risking going out of the boat if anything bad happens. Fast enough for me in my old age, especially with about no water under you.

My boat is light, with a 14 gallon gas tank, 1 battery, trolling motor, 15 pound anchor and 2-bank charger up front, and only 1 battery and the engine in the back. No livewells, big decks or other heavy things. Not even seats, except for a light plastic swivel seat for the driver. Console is on the right side about 6 feet from the bow. It floats and planes almost dead level.

 

[smackdaddy53]

I haven't seen a description of your boat and layout. Would like to see your boat specs and the performance you're seeing. Here is what mine looks like for comparison.

I ran a 40/30 Merc on my Roughneck 1655 tunnel hull for almost 20 years. Best it would do is about 24 MPH, but it would jump on plane right now. It was underpowered, but worked just fine. Just upgraded to a 60/45 Merc, and now it goes a little better than 29 MPH tops, downhill through shallow rapids. I have the front of the intake foot about even with the top of the tunnel, so the whole jet nozzle is out of the water, and the whole foot is above the bottom of the hull. I can't run the motor with someone standing on the front deck, because it will lift the whole intake foot out of the water. When I hit something, I hit it with the hull. (If you're not hitting stuff, you're reading the wrong forum.)

The 60/45 gets to top speed quicker now, and will cruise at 24 MPH easy at about 2/3 throttle. The new motor has a 3 blade Stainless impeller. I think any faster than 29 on my home waters, and you're risking going out of the boat if anything bad happens. Fast enough for me in my old age, especially with about no water under you.

My boat is light, with a 14 gallon gas tank, 1 battery, trolling motor, 15 pound anchor and 2-bank charger up front, and only 1 battery and the engine in the back. No livewells, big decks or other heavy things. Not even seats, except for a light plastic swivel seat for the driver. Console is on the right side about 6 feet from the bow. It floats and planes almost dead level.

My boat is definitely not bare bones. Check out my build on the jon boats and v bottoms under "smackdaddy's pole dancer tunnel jet".
1652 with 6" step pods, front and rear deck, trolling motor, 4 optimas under console, 25 gallon gas tank under bow deck. Right now I am running it with 5 gallons of gas in the tank. I may fill it up and see what happens but I am not too optimistic. I may be going with a 90 or even a 115 by the looks of it. My motor is strong. Less than 80 hours, fresh carbs, about to throw in some carson racing reeds and maybe an exhaust tuner to gain some HP. I may even do some real motor work and see what happens. I would like to keep my draft where it is, close to 6" but don't see that happening with a 90 or 115. Brand new stainless 3 blade impeller with no sharpened edges or buffed jet castings but I will do that at some point. I have not weighed my boat but I guesstimate 1000# with everything plus me which may be conservative.
Here is my framing- 2x2x1/8" tubing with 1/8" decking.

 

[dhoganjr]

I can tell you a 115/80 Fourstroke pushed my 1860 to 36 mph gps flat out, 1-2 mph faster down river. It ran good with just me but add more gear and people and it was way underpowered and took a runway to climb on plane. The boat has extended front deck and rear deck, 24 volt trolling motor, 2 batteries under front deck, livewell, rod box, 2-12 gallon fuel tanks and starting battery in rear. The 250/175 pushes same load plus 3 gallon oil tank in rear to 49 mph.

Semojet runs a 1856 with a 60/40 Fourstroke and gets about 30-31 if I remember right.

I think Lil Blue Rude is running mid to upper 40's with a 60/40, extensively modified of course.

I think you should be seeing at or near 30 with your setup and it should plane pretty good with a 60/40, why it is not I don't know.

I don't know what your boat is rated for but most 90 and 115's are in the same weight class if that is the direction you go and with pods should only draft about an inch more.

 

[smackdaddy53]

Since I have a nice clean motor maybe I should just modify the hell out of it and see what happens. For now I am going to keep moving weight around and setting the motor.
I don't care much about speed as just getting out of the hole and on plane as fast as possible.

 

[dhoganjr]

Just wanted to give you a ballpark on where it should be with verified numbers.

 

[smackdaddy53]

Just wanted to give you a ballpark on where it should be with verified numbers.

I appreciate it! I am about to start on it.

 

[smackdaddy53]

I got my transom wedges and splash plate fabbed and installed. I think this is the ticket! I am going to run it tomorrow (weather permitting) and see how it performs. I believe I am going to put about 10 gallons of gas in the tank to help get some weight forward.

 

[LarryMc]

smackdaddy53 » 02 Sep 2014, 20:38[/url]"]How much play should the shaft have left and right? I read with a stainless impeller you can go to within .015" but it feels like my shaft moves at least that much when I remove the foot and give it a little wiggle. Is this normal or did I somehow not install my bearing kit correctly? Looking at the mechanics of it there really should not be any play at all because the bearing is pressed on and the housing holds the bearing in place with four bolts. I am positive I installed the kit correctly and definitely have plenty of grease in the system because I shot some in twice already and it came out clean from the grease return hose.
I ran it on the hose this afternoon after I re shimmed and the tolerance is definitely where it needs to be but still had a little contact with the liner.
I hate to keep asking all these questions but I really thought this was going to be fairly cut and dried. Next step is to just put all shims on the nut side of the impeller and try it. I just bought this impeller and liner and I am not at all thrilled about ruining one liner already and scratching up the edges of my $380 stainless impeller. It just seems that if I remove all the shims from behind the impeller my leading edge impeller tolerance is going to be a hell of a lot more than .030".

I don't think you should have any side to side play after bolting the shaft back in. If it were me, I would call Outboard Jets and ask them about it. One thing to check, is the bearing carrier still in the same place on the shaft where it was after you installed the bearing kit and pressed the carrier back on? About 4 years ago, the shaft on my motor slipped down through the bearing carrier about 3/16" and ruined both my liner and the impeller. Had to buy a new shaft, liner and impeller. It's entirely possible that your shaft slipped down a little after running for a while and caused the impeller to start hitting the liner.

FYI, about a month ago I put a new liner and new stainless impeller in my 2005 Merc 60/40 along with a shaft rebuilt by Outboard Jets. With all the shims on the nut side, the clearance was .020".

 

[smackdaddy53]

smackdaddy53 » 02 Sep 2014, 20:38[/url]"]How much play should the shaft have left and right? I read with a stainless impeller you can go to within .015" but it feels like my shaft moves at least that much when I remove the foot and give it a little wiggle. Is this normal or did I somehow not install my bearing kit correctly? Looking at the mechanics of it there really should not be any play at all because the bearing is pressed on and the housing holds the bearing in place with four bolts. I am positive I installed the kit correctly and definitely have plenty of grease in the system because I shot some in twice already and it came out clean from the grease return hose.
I ran it on the hose this afternoon after I re shimmed and the tolerance is definitely where it needs to be but still had a little contact with the liner.
I hate to keep asking all these questions but I really thought this was going to be fairly cut and dried. Next step is to just put all shims on the nut side of the impeller and try it. I just bought this impeller and liner and I am not at all thrilled about ruining one liner already and scratching up the edges of my $380 stainless impeller. It just seems that if I remove all the shims from behind the impeller my leading edge impeller tolerance is going to be a hell of a lot more than .030".

I don't think you should have any side to side play after bolting the shaft back in. If it were me, I would call Outboard Jets and ask them about it. One thing to check, is the bearing carrier still in the same place on the shaft where it was after you installed the bearing kit and pressed the carrier back on? About 4 years ago, the shaft on my motor slipped down through the bearing carrier about 3/16" and ruined both my liner and the impeller. Had to buy a new shaft, liner and impeller. It's entirely possible that your shaft slipped down a little after running for a while and caused the impeller to start hitting the liner.

FYI, about a month ago I put a new liner and new stainless impeller in my 2005 Merc 60/40 along with a shaft rebuilt by Outboard Jets. With all the shims on the nut side, the clearance was .020".

The tolerance is not an issue any more, now I am wondering what the issue is with my setup and why I can't get on plane.
This morning I replaced the factory stainless reeds with Carson racing reeds and inatalled transom wedges to tuck the motor under more so I could maybe get the nose down. WRONG AGAIN!
I ran by myself with 15 gallons of gas in the bow tank and it still dogs. I am not sure what the deal is. I am going to keep picking yalls brain and Monday I am taking this rig to Sonny's Marine and see what he thinks the deal is. He has been running and rigging jets on rigs like ours for 20 years.
Here are a few pics of the rear end. Anything look out of place or just wrong?
I am having a hard time convincing myself the 60 is underpowered for this boat but who knows. I know one thing, 17.8 mph today was the fastest I could get it but it never fully got on plane. Do I need trim tabs and/or power tilt to help get it up? The motor is running great but something is just not right.

 

[dhoganjr]

One question come to mind, do you have a tachometer on there to verify that you are turning max rated rpm's .

 

[LarryMc]

dhoganjr » 06 Sep 2014, 20:34[/url]"]One question come to mind, do you have a tachometer on there to verify that you are turning max rated rpm's .

I was thinking the same thing. At WOT for that motor you should be running between 5000 & 5500 RPM. My motor runs 5250 at WOT.

What size is your tunnel? It looks pretty big to me in the photo.

 

[smackdaddy53]

Still trying to figure out what setting to set the dial on the back of my tach. I do know the motor is definitely not bogging down. If it were cavitating I would probably hear it right?

 

[dhoganjr]

The motor setting and height all looks good. I'm betting it's not turning max rpm's. It will run fine and not bog down, but if you are not getting full throttle you will have a hard time planing and getting speed. You would know if it was not running correctly, but not if it's not turning full rpm's without the tach telling you so. I say get the tach working asap, I am guessing it could be in the linkages.

With motor off put it in full throttle and make sure the butterflies are fully open. I think we may have been working on the wrong end.

 

[smackdaddy53]

The motor setting and height all looks good. I'm betting it's not turning max rpm's. It will run fine and not bog down, but if you are not getting full throttle you will have a hard time planing and getting speed. You would know if it was not running correctly, but not if it's not turning full rpm's without the tach telling you so. I say get the tach working asap, I am guessing it could be in the linkages.

With motor off put it in full throttle and make sure the butterflies are fully open. I think we may have been working on the wrong end.

You guys have to excuse my lack of knowlege as far as motors and jets because this is my first "real" boat. I can build and learn just about anything but I have to have hands on experience rather than just research.
dhogan, That makes sense because I have only adjusted the idle by ear and have not even messed with the throttle settings. That may also explain why I have to push the lever so far forward to get much response.
I looked up my tach and it shows I need to set it on 6P for my motor. Here is a pic of the back of my tach.

 

[dhoganjr]

Setting up the tach, I don't know much about. But the throttle linkage where the cable attaches to the motor controls all 3 butterflies and can be adjusted on the linkage. Check that when you open it to full throttle all 3 fully open. I hope that is the problem because that is a simple fix.

It just happened to come to mind when you said it only got 17.8 and never got on plane, that would be around the 3500 rpm range just guessing. I know a 60/40-45, whichever it is, should plane that boat pretty quick and should get near 30 mph.

 

[smackdaddy53]

I sure hope you are right bro! I was about ready to get a 90