When you say "cable fails at the brass" Where should I look? Sorry, I'm pretty mechanically inclined, but new to drive terminology. Can I check it with the drive and engine in?

thanks

Would it be worth a try to extend the travel of the cable at the bracket arm and see if this helps? Could it hurt anything more than I've already hurt it (probably sliped it 8-10 times now)

If you turn the wheel hard left, trim drives up most of the way and look in the gap for a black cable, forward it passes into a bellows then in to transom. look aft where it enters the bellhousing " the part the drive bolts to" ,it has a brass fitting which threads into the housing. Very often the cable wears out there. The inner shift cable the cable just described is a 3-5 year service item. If that cable is bad you will lose travel. When you replace the cable there is a tool and a specific dimension to set it to. It should not ever need to be adjusted unless something is going away.At that point adjusting it treats the symptom not the problem.
Jim

Possible but not likely that it would continue to it on several trips out.

What prop are you running???? Sounds to me like you are just blowing out/cavitating the prop when you have a heavy load.

So far I've run a 25p Stilleto 3 blade, a 24p Stilleto 4 blade, a 23p Bravo 3 blade, a 17p LH (to try LH), and now a 25p Bravo 3 blade LH.

It does it at 60mph at a little over half throttle or coming on plane with the secondaries barely open (less load than the stock 330HP 454 put on it).

This weekend, once it happened (just a split second at 5000rpm before I caught it and backed off), even after backing off, I could barely stay on plane at 30mph 3600rpm. Once I let it cool down and brought it back on plane (same load in boat) I ran 15 miles at 45mph at the same rpm (3600) with no issues. The intial slipping (30mph at 3600rpm) was barely into the throttle at all.

I can't imagine prop cavitation could be variable like that. Especially at really low load. But I'd be willing to try anything at this point. Just talked with someone about buying a recently rebuilt drive. I guess it doesn't hurt to have a spare drive around, but I'd sure like to figure out the source of the problem before I start pulling the boat apart in the middle of our 10 minute long summer (Michigan)

And yes, it's now done this on quite a few occasions. Everytime, I think I've got it figured out and a week later it happens again. It is getting worse everytime it happens. Got better when I switched to LH prop, but I'm sure it will start to get worse if I keep running it this way.

Thank you, very descriptive. I'll pull it out of the water and take a look.

Never rule out prop problems. I ran 3 blade Mirage +'s with boat stock. Then procharged it and I could not get any of the Mirage +'s to hook. I thought I broke a top gear again, but was okay. I had solid hub props so I knew it wasn't those. Checked coupler and that was fine.

Threw a stock Bravo (4 blade) Prop on it and wallah - no more slippage.

Was really frustrating to have to come back to almost idle for prop to re-grab and then try again. Sometimes turning at speed would make me cavitate where I'd have to come back to off idle.

Really sucked !!!

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Not saying this is your problem, but I didn't believe it either - I tried it after checking coupler instead of before it. Live and learn. Doh.

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Possible drive shower or thru transom water pick-up causing your prop to cavitate ? I've heard of this happening but personally have not run into this one yet.

Is it possible to have some kind of disturbance in the water leading to the prop (air bubbles) ? Sure sounds like blow-out to me too... I had a similar problem but with TRS and cleavers.

With your latest description it really sounds like you are blowing out props to me. How big in diameter is that Stilleto 4 blade? You have a lot of small diameter props from what I gather. Try a Bravo 1, 4 blade and I think your problem will disappear. When you say cool off, do you mean literaly wait for a temp to come down or just wait till the boat settles and then try again? If I start falling off plane and allow the prop to blow out on my boat, I have to bring it back to idle and get it back on plane again. Your drive trim can also play a role if you are trimming out too soon or too high. Some boat/prop combos are more sensitive to ventilating the prop than others. It really doesn't seem like you have a drive problem. It would have come apart as soon as anything slipped. Same goes for the coupler.

Rene

the 4 blade is a 13 3/4. I'm no expert on describing this stuff, but I'd say the 4 blade bit way too hard. Seemed to be driving the bow into the water. Couldn't get the bow trimed up no mater how high I pulled the drive. I don't remember how bad it slipped. It was one of the first props I tried. Maybe I'll give it another try and see if it's better or worse as far as slip is concerned.

I did install a drive shower with the engine upgrade, but the pickups are significantly behind the prop.

Once it starts to slip is does actually need to cool. Just taking it off plane won't do it. Tried that once and had to idle two miles back to the slip. Next time it happened, I let it sit for an hour and it came right up on plane.

Also, if it were prop slip, how would it keep getting worse? Prop slip was my first assumption as well, but after this many props I gave up on that assumption. The drive is very deep (as they all were in '93) so I'm really struggling to figure how all these props could be ventilating. Again, who knows though.

This weekend, when it started to slip, I had my tabs about 3/4 down and the drive all the way down. Once it came on plane, I laid into it very gently, maybe half throttle, and wham, 3000rpm to 5000rpm in a split second

The only prop I haven't tried is a 25p cleaver. I guess I could give that a try. The 25p bravo I have on it right now runs fantastic when it's not slipping. Smooth as silk and an extra 5 mph more than any other prop I've run (effortlessly at 4000rpm)