Texasmark
Supreme Mariner
- Joined
- Dec 20, 2005
- Messages
- 14,559
Since we have had precious rain for the last two days I was surfing to compete with the cabin fever boredom.
Wound up on the Yammie site and on into the prop section. Some really good info in there that answers a lot of questions that people ask on here.
Figuring out how the no clunk works, it appears to me, looking from the rear, that the nut is torqued to put the rubber of the hub into compression. Then then you shift the rubber deflects absorbing the shock and the key on the rear, splined to the prop shaft moves on over and contacts the metal of the prop barrel thus giving you a metal to metal to metal contact.
Makes sense.
Sooooo apparently the hot dog change out your hub to save inventory thing results in noisy operation and Yammie went out to fix it....patent pending.
I still have the old fashioned rubber slip hub (which they have in some of their props) and it is a no clunk hub and when I hit something I am metal to rubber to metal. But on the Yammie, I would expect that the eared splined washer that goes on prior to the nut and locks things up, shears off if you hit something big so yes, you are immobile, but no you didn't rip out your gear box.
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Noticed that they said that they have "ported" props for 2 stroke engines but with their lineup of 4 strokes all the props they had pictured had none and the article said they weren't needed for the torque curves of 4 strokes. So I guess that answers the questions that come up about I/O rigs running ported props.
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Noticed the mention of the extended barrel to help to prevent exhaust gasses from interfering with the props in reverse.
I didn't know that. Looking at the flares and rings of yesterday, it looked like forward motion performance was the reason.
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They went on to talk about rake and effects of too much, cupping, and effect of number of blades.
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They mentioned something that comes up from time to time on here. I call it "clutch dog rattle", they called it something else and then went on to explain that with 4 strokes at idle in F you can get this clunking noise which is the clutch dog not making permanent contact with the F gear and in going back and forth it bangs and clangs. They said it hurts nothing (gears are heat treated and unbelievably hard...BTDT) and the bumping the rpms up as few as 100 can make it stop.
I have had this occur with my Merc 2 stroke 3 cyl when I put a very high pitched, heavy SS prop on the engine and as they mentioned, I just increase the rpms until it quits. However, when I put a couple of my other props on with less pitch and weight, I don't have the problem.
All in all, being a Merc guy, I enjoyed the time spent on the site.
Thought this was interesting and you might like it. Certainly answers a lot of questions and I felt good that my experiences that I share on here are in line with their test proven facts. Oh and they are made and tested in the USA.
Oh, and with respect to the name's sake, similar info is on the Merc. site. However I found this to be more definitive of things other than their new hub.
Mark
Wound up on the Yammie site and on into the prop section. Some really good info in there that answers a lot of questions that people ask on here.
Figuring out how the no clunk works, it appears to me, looking from the rear, that the nut is torqued to put the rubber of the hub into compression. Then then you shift the rubber deflects absorbing the shock and the key on the rear, splined to the prop shaft moves on over and contacts the metal of the prop barrel thus giving you a metal to metal to metal contact.
Makes sense.
Sooooo apparently the hot dog change out your hub to save inventory thing results in noisy operation and Yammie went out to fix it....patent pending.
I still have the old fashioned rubber slip hub (which they have in some of their props) and it is a no clunk hub and when I hit something I am metal to rubber to metal. But on the Yammie, I would expect that the eared splined washer that goes on prior to the nut and locks things up, shears off if you hit something big so yes, you are immobile, but no you didn't rip out your gear box.
---------------
Noticed that they said that they have "ported" props for 2 stroke engines but with their lineup of 4 strokes all the props they had pictured had none and the article said they weren't needed for the torque curves of 4 strokes. So I guess that answers the questions that come up about I/O rigs running ported props.
--------------
Noticed the mention of the extended barrel to help to prevent exhaust gasses from interfering with the props in reverse.
I didn't know that. Looking at the flares and rings of yesterday, it looked like forward motion performance was the reason.
---------------
They went on to talk about rake and effects of too much, cupping, and effect of number of blades.
-------------------
They mentioned something that comes up from time to time on here. I call it "clutch dog rattle", they called it something else and then went on to explain that with 4 strokes at idle in F you can get this clunking noise which is the clutch dog not making permanent contact with the F gear and in going back and forth it bangs and clangs. They said it hurts nothing (gears are heat treated and unbelievably hard...BTDT) and the bumping the rpms up as few as 100 can make it stop.
I have had this occur with my Merc 2 stroke 3 cyl when I put a very high pitched, heavy SS prop on the engine and as they mentioned, I just increase the rpms until it quits. However, when I put a couple of my other props on with less pitch and weight, I don't have the problem.
All in all, being a Merc guy, I enjoyed the time spent on the site.
Thought this was interesting and you might like it. Certainly answers a lot of questions and I felt good that my experiences that I share on here are in line with their test proven facts. Oh and they are made and tested in the USA.
Oh, and with respect to the name's sake, similar info is on the Merc. site. However I found this to be more definitive of things other than their new hub.
Mark