|
|
Posts: 2097
| I recently broke my optimax prop and used the numbers off it to buy another stock mercury black max prop.
I went from the flow tourque 3 assembly cause I could not get the sleave out of the old prop so I used the flow tourque 2 assembly that came with it.
I hole shot is better but I have lost 2-3 mph off top end. It is also runs the same speed at 3000 rpm as the old one did at around 34-3500 while cruising to spots conserving fuel.
Is there small differences in props from the factory?I
I like it better now cause I don't run wot anyways, just curious.
Edited by cave run legend 4/15/2013 3:48 PM
|
|
| |
|
Posts: 440
| Props are not consistent coming out of the jig. Most guys chasing the top end often send the props off to specialists. 26" Tempests are notorious for being inconsistent. |
|
| |
|
Posts: 2097
| I have a 13" 19pitch mercury black max aluminum. Thanks for the info. |
|
| |
|
Posts: 532
| This is a long shot, but check your prop shaft to make sure it is still running true. From the story you had it doesnt sound like you hit it hard enough to bend it but its worth a check.
Also double check that your new prop has the same part # stamped on it, just because you ordered one thing you may have gotten somthing different. Check to make sure they are the same. |
|
| |
|
Posts: 2097
| I will. The shaft is running true. Is the reason I could not get the old sleeve out of the old prop was because it failed? I have read with the flow torques assembly it is designed to fail before the shaft bends. I even took a hammer and chisel to it. The motor is smooth and has zero vibration even at wot.
Edited by cave run legend 4/15/2013 7:55 PM
|
|
| |
|
Posts: 532
| Like i said long shot, the hubs are ment to be sacrifical but that does not mean they protect 100%.
Since your prop shaft runns true thats one less variable.
Check to be sure you do have the same prop. |
|
| |
|
Posts: 2097
| So I filled the boat up this morning and went to the lake. I added 15 gallons to it. Again great hole shot, great mid range, but topped out at 40mph gps speed again. Previously with the old prop it lagged a little bit in the hole shot, more rpms to cruise it at 30mph, and topped out at 43mph.
I came home and took the prop off. I hooked the muffs up and engaged it in gear. I looked at the hole in the end of the shaft to see if it was distorted, moved, or anything weird looking. Straight as a arrow. I then took a coat hanger and put it in my jaw horse and put the end of it right on the edge of the hole at the end of the prop. I turned it by hand and it was straight as an arrow again.
I have the same numbers on this prop as the old one. It feels like the pitch is different. Can a minute difference affect me like this?
Thanks |
|
| |
|
Posts: 3504
Location: Elk River, Minnesota | Hiya,
I've been watching this one a bit and I did get your PM as well. Is the original prop one that came with the motor when you purchased it? I'm wondering if the prop you had was maybe re-pitched up a tad, which would explain the difference.
Everything seems to point at a different pitch or diameter. How do the RPM's compare at full throttle? Gut says you have higher RPM's at full, but want to confirm.
This on a 115?
Steve |
|
| |
|
Posts: 2097
| Thank you Steve,
I don't remember what the WOT was on the old one. This one is around 5600. The boat was purchased new last year with the original prop. Yes a 115 Optimax.
I doubt the dealer re-pitched it up. The only thing I can think of is that there is a slight difference between the two props.
Edited by cave run legend 4/16/2013 10:14 PM
|
|
| |
|
Location: Eastern Ontario | If there was a prop repair shop near you he might put it on his jig and verrify the pitch. |
|
| |
|
Posts: 3504
Location: Elk River, Minnesota | Was thinking today a bit more about things and started looking into the different hubs. Looks like either hub will work, so I don't think that is any issue.
Any chance you still have the old prop and could take pictures of a decent blade and take a picture of the new blade?
Wondering if there could be some design differences there.
Gut instinct says pitch is different by about 2"... That would explain the better hole shot and lower top end...
On another note, ever considered going steel with your 115?
Steve
Steve |
|
| |
|
Posts: 2097
| Thank you Steve,
No I went ahead and threw the old prop aways, didn't think I would need it. Right now I will just keep what I got. I like the better low end, I never hardly run WOT. If I decide I need some more top end I will let you know.
Thank you for the help. |
|
| |
|
Posts: 3504
Location: Elk River, Minnesota | Sounds good...
That low end can really at times be more important that top end. Low end torque plays a huge role in bad conditions...
Steve |
|
| |
|
Location: 31 | VMS - 4/17/2013 6:58 PM
Sounds good...
That low end can really at times be more important that top end. Low end torque plays a huge role in bad conditions...
Steve
Spot on! We seem to start out with maximizing our boats top end, and then maybe the hole shot, when in fact rough water performance is just as (if not) more important on larger water.
I fish in 2-4’ seas quite a bit and having the mid range torque to help keep the boat on plane (or harder yet… almost) under these fairly normal conditions is well worth the 7-8 MPH I give up on the top end. In my experience, it's just not worth the extra "fight" with the boat in rough water with a prop that's designed to squeeze out every top end mile per hour… especially with a four stroke.
Frankly, I kind of marvel at Steve's great advice here on First, and have learned a lot from him here though the years... we are fortunate to have this kind of great advice available with just a few mouse clicks.
|
|
| |
|
Location: Green Bay, WI | You have a great motor for the water you fish Jerry--it's not fast, and it's not glamorous. But it does have enough snot to get you out of the hole and on-plane, is virtually bullet-proof, and it does well at the mid-range RPM that you seem to have to run most of the time out there. It's a VERY smooth engine, and overall I think you got a sweet combination...
TB |
|
| |
bought the same replacement prop but lost top end?