Flo-torq II and XHS hub users.....

[Texasmark]

Re: Flo-torq II and XHS hub users.....

Well maybe that's what I heard when I put the Hustler (alum) on. After all the hype about heavy SS props and the "clutch rattle" I thoroughly expected no rattle with the light prop, but I got some; significantly not as much however.

So the next time I put the Hustler on I'll torque her up and see what happens.

I guess, since Merc said do it, that the brass prop nut is capable of that kind of torque. :/

Mark

 

[walleyehed]

Re: Flo-torq II and XHS hub users.....

It may have some brass, but it contains other alloys as well...infact, I believe it is close to Bronze.

 

[Texasmark]

Re: Flo-torq II and XHS hub users.....

Probably right on the bronze which is significantly harder than brass.

Mark

 

[scsims]

Re: Flo-torq II and XHS hub users.....

I have mine torqued to 100ft pounds, I'll you know if it helps.

 

[scottsims]

Re: Flo-torq II and XHS hub users.....

At 100ft pounds it helped the clutch rattle a little but it's still there.

 

[walleyehed]

Re: Flo-torq II and XHS hub users.....

I agree...it didn't take "all" of the rattle out, but the manufacturer says it's normal to have some clatter...?
My Enertia, or any with this type of hub, rattle some....I don't like the sound of it, and I'll likely be going back to a std hub system.
Turbo has come out with a replacable hub system for a series of their props as well...I hope they don't go that way with all of their props.

 

[pursuit2460]

Re: Flo-torq II and XHS hub users.....

I have a Rapture with the XHS hub. Is the clatter you hear when you back of the throttle from wot run. When I first bought this system I was running wot and when I back off to almost idle I heared a clattering nosie. I thought it was my engine. Anyways I havent done the wot to idle again in fear of something is going to go wrong. Also I only put the nut on hand tight and then alittle turn with a wrench. Its a 93 225 johnson. Am I suppose to tourque it to 100lbs to lose the clattering.

 

[jimmbo]

Re: Flo-torq II and XHS hub users.....

The Flo-Torq II kit for my motor, Volvo Sx, says to torque the nut to 55lb ft, not 100

 

[Texasmark]

Re: Flo-torq II and XHS hub users.....

ajc 1219. Yes to your backoff question.
--------------------------------
Think about it guys and gals, what's this clutch dog hootus in there for in the first place.

Well your prop is a gear tied to your engine. Water is a semisolid and at high speeds is more like a solid cause it is till you move it out of the way; it doesn't compress. d

So when you are at WOT and dump the throttle, if there wasn't a slip clutch of some sort the prop would attempt to follow the engines rpm and try to shut down (from 5000 rpm to 700 engine rpm's) in as short a time as it could get the water out of it's way.

For the boat and it's occupants this could be like running your car into a brick wall.....had it happen on an engine siezure once and you can't believe how fast your boat will stop when you freeze the prop at WOT.

So early designers put in the slip clutch, spring loaded so that it will engage when required and disengage any time the engine is going slower than the prop.....in Forward gear that is; not used in Reverse....at least not on Mercs.

Most of the time you don't hear it clattering when slowing down (usually too many other things making noise that masks it) but you said you heard it.....interesting cause it's there and rattles every time you slow your boat........so the gears must be designed to tolerate it. Right? d

So apparently what happens, with out new high performance, heavy, high pitched, high raked, multi-bladed props of current design, is the combination of weight and increased turbulence at low speed (idle in particular and particularly on engines with few cylinders) we get pulsating torque differences between the prop shaft, prop, and drive shaft that cause the clutch to get pushed and pulled on and causes the dog to slip and catch and slip and catch, which is the rattle.

If the hub to propshaft interface is loose (requirement for the 100 ft-lbs of torque on the nut) then that would be an additional slop which could cause noise of it's own and also could add to the instability applied to the clutch dog resulting in more intense rattling.

Phew My 2c.

Mark

 

[ParallaxBill]

Re: Flo-torq II and XHS hub users.....

Good to know, now I gotta find my torque wrench and crank down on mine. Just installed it last week tested it Sunday, heard no noise, had not problems but mine is definately not torgued to 100 Ft/Lbs.

Thanks,
Bill

 

[Texasmark]

Re: Flo-torq II and XHS hub users.....

Don't fix it if it ain't broke. If your rig is running OK, leave it alone.

Mark

 

[walleyehed]

Re: Flo-torq II and XHS hub users.....

jimmbo, for the std hub, tighten nut to 55ftlbs...for flo-torqII hub kits, tighten to 100ftlbs on ALL large gearcase set-ups. The Volvo SX fall into the Large class.

 

[pursuit2460]

Re: Flo-torq II and XHS hub users.....

So the noise I here when backing off from wot to almost idle is normall. My nut is probally at 20-30lbs. When I bought my prop 2-2 1/2 years ago I never got the instruction with it or the hub atleast nothing saying 100ft lbs.But I should tighten my nut to 100 ft lbs anyways right. By the way what would happen if I dont. I ve had it like this for 2 1/2 years and no problems. thanks

 

[walleyehed]

Re: Flo-torq II and XHS hub users.....

Both the fwd thrust washer and aft nut/washer assembly must be tightly seated against the delrin sleeve in a flo-torq hub for best results and the least amount of excess Rattle.

 

[Chopper Doc]

Re: Flo-torq II and XHS hub users.....

I wouldn't recommend testing the hub out. Chances are if you are running an aluminum prop you'll break it. I can give you my experience with this. It was purely accidental mind you, at least not purposeful on my part. I was at the dock at a nearby lake unloading a passenger when two skeadoo things came in wanting to use the ramp. I backed out and proceeded to the other side of the dock away from the ramp as a curteous boater might do. I am not a dock hog but I have seen a lot. Anyway, I completed my business and as I was backing out one of the skeadoos was against the opposite side of the dock and decided he would power out back into the lake...I never really knew those things developed so much underwater thrust. His jet blast pushed my boat sideways into a submerged tree limb that wasn't visible to my until it went into my prop. By the time I went from reverse into nuetral the damage was already done. I can only guess that the limb wedged itself between the cavitation plate and the spinning prop. Unfortunately for me the plastic hub did NOT sheer, strip, or break. Two prop tips did break and the third one was bent roughly at a right angle. Needless to say that was the end of my trip. I did go to the local boat shop and Todd ordered me a replacement prop and I had the old prop repaired but it looks like crap and I only carry it as a get-home spare now. I don't know how much torque I have on my prop nut but I used a big wrench to put it on with and I am a big guy and I did tighten the crap out of it. The only problems I have with it is that I think I need to get a SS prop and can the alum one. I have a 2005 Tahoe Q4 Sport (19 1/2 ft) with a Mercruiser 3.0 I/O. It came factory with a 14.25 by 21 pitch alum prop. I replaced it with the same. My boat with my normal loadout at WOT 4600-4700 rpm and on the gps at 40-42 mph depending on the day. It does occasionally seem like it may be cavitating at wot sometimes, or is this called venting? It will make higher pitched sounds from the prop like it is coming out of the water or maybe sucking air. I can slow down a bit and it stops. The boat will pull a skier just fine with three people on board. Many folks on these forums frown on a bigger boat with this engine setup but even though it is not a faster boat on the water it does seem comfortable. Is there a good SS replacement prop for this boat? Or should I just leave it like it is and just expect to replace the prop periodically?

Well, if you do decide to test your prop hub with the alum prop good luck and I hope you dont loose any parts.

Wes

 

[John_S]

Re: Flo-torq II and XHS hub users.....

I haven't had any replacable hub system, save the alum prop from damage. IMHO, they are primarily so mfgs can have some eonomy from making a gazillion different props to fit all the main drives and outboards. BTW, I have had a number of plain rubber hubbed props fail, just from age. I much rather have been able to just replace the hub.

 

[Crownie2]

Re: Flo-torq II and XHS hub users.....

Chopper Doc - my advice: go to the Merc web site and check out all the offerings. Your RPM range seems to be good to high now so you could go with the same pitch in a SS.

Good Luck

Bob

 

[Chopper Doc]

Re: Flo-torq II and XHS hub users.....

Yep! I put on an Apollo SS 14 * 21 and it seems to have worked out great. Max speed with me in the boat was 44 mph @ 4600 rpm. It pulls much harder and seems to stay up on plane at a lower speed. It also handles a lot better as well. I can't explain it but it handles and tracks better in rough water way better than it used to. I can maintain a higher speed through turns and make sharper turns and it seems to hold lower speeds in sharper turns more consistantly too without falling off plane. I ran it in the bay this weekend with 4 people on board and maintained 40 mph @ around 4000 rpm. If the water had been smoother I could have been able to trim the nose up and run a little faster...but for the comfort of my passangers I decided the water was a little too rough for that.

Wes