engine coupler ?, can it be a momentary problem

[elkhunter338]

Today had an issue when I accelerated the boat, came up to about 2,000 rms then reved slightly, I immediatly backed off on the throttle.
I tried again and it did the same thing, headed for home at an idle. Figured engine coupler spun in the rubber housing and did not want to loose all power to the prop.

Got back to dock and decided to try it again, no problem at all ran fine.
1. has any one had a similar problem with an engine coupler spinning then seeming to be ok?
2. a charter boat had crossed fairly close to us and the only other possibility was we where still in the prop wash and the air bubbles let the prop cavitate. Never had this happen and i have run the boat 600+ hrs.

I am leary of head back out in the ocean not knowing for sure what the issue was or if I have an issue.
Please don't post theories only real world experience is needed.

Merc. 140hp I/O

Thanks,

[FreeBeeTony]

Any posibilty you had some weeds wrapped around the prop?

[elkhunter338]

FreeBeeTony,
Could have been a possibility, ocean was kind of rough so I really did not investigate too much at the time.
I just read another posting where a guy installed a hydro foil and had cavitation problems.
I did just put a trolling plate on the motor, so maybe it trapped some bubbles around the prop? Ran the boat yesterday 25-30 miles with no trouble.

[fishrdan]

I would think the prop hub was slipping more than the coupler hub. You can mark the hub and prop with some white paint, to see if it's slipping.

Seeing as this only happened once, you might have just had some cavitation. I get it every once in a blue moon, heavy seas or turning too tight with too much power. I never paid too much worry about it. Oh yeah, I have a Troll-a-Matic plate on my boat and never have associated it with cavitation, loss of steering input at slow speeds yes, but not cavitation.

[paultjohnson]

IMHO there is no chance your coupler could slip and then work again. Its not like a belt on a pulley or a manual clutch on a car that gets wet, slips, then dries off and works again. Its splined, and once the coupler strips out, its stripped, , and there is nothing left to engage the drive shaft anymore.. I believe on some of props, you may get a little bite after the prop hub spins, but not the coupler.

[thumpar]

Any posibilty you had some weeds wrapped around the prop?

I bet that is what it is. Happens to me as the season gets later and the lakes warm up around here. I have to putt to deeper water after launch and clean the weeds off every time this late in the year. If I don't I get the same thing happening to me, goes fine until about 2k-2500 then it is like it just looses traction.

[elkhunter338]

1. can't be the prop, composite prop with no rubber hub. If the prop splines spins they are gone
2. not engine coupler splines, but I could not recall if the coupler has a rubber hub.
I know the older merc couplers had a rubber hub, but not 100% about the newer ones.

I am going to go with cavitation at this time and run the boat if the weather gets better.

Thanks for help guys I will post again if something for sure turns up.

[ianwoods]

I'm having a simlar issue elkhunter, do all composite props have no rubber hub ? I was led to believe they do have one.

I was also advised a plastic bag around the prop would cause this feeling momentarily, maybe that is what you had. Mine comes and goes too but it leaves a bit of uncertainty on the bigger outings.... :-(