prop strike; think it's fixable?

In our 1995 GT40 with a 422 Acme at a flat idle it still has a wake and near marina's I have been yelled at several times.  I just try and swing wider so I am on the far side from the tied up boats and when they yell  I am farther away and ignore them.  I think some of those guys just sit on their docks waiting for someone to yell at after several beers.  I do stay at idle, not like some that you hear rev up to 1,000 or more RPM to get out of the no wake zone faster.

Jonny Quest wrote: Nice.  I run a 654 on my Bubble-But Ski.  At 4,400 feet of elevation, the pitch is just about perfect.  JQ

Not sure if this is an issue with my boat or the prop, but I’m incapable of a no wake speed. Barely in gear it puts out enough wake that I’ve been yelled at on numerous occasions. Of course I can always blip in and out of gear.

I’ve got the idle set to as low as it’ll go without stalling.

Have that problem?

Happy to report I found a new 654 prop on Facebook marketplace. Installed it today. Ran the shaft on the dial gauge and found it only varied by *maybe* 0.002, and probably more importantly, the boat runs like a top with no vibration using the new prop. Think I got lucky on this one!

You want to be as close to the threads on the prop as possible but need to check on the smooth surface and avoid the key way.  I have seen some clamp mount dial indicator bases that have a stiff but flexible attachement.  One of those might make the job easy for you.   I do not recall exactly where I ended up measuring mine but I had a significant bend so mine was obvious.

MrMcD wrote: I used a magnetic mount for simplicity, I had one already, it mounted easy to my prop gaurd and was in a good position to place the dial indicator on my prop shaft.  I recall it was hard to find a place where the taper or the prop key slot was not in the way.  I am sure any mount system could work, some clamp on that would be fine also and if your trailer did not have a prop guard right under the shaft that would be more of a challenge but I think most Nautiques use a prop guard. This shows a couple of cheap dial indicators,  I thought mine was a cheap one at a couple hundred dollars 25 years ago, now you can have one for $50.   Mornajina Electronic Digital Dial Indicator with Magnetic Base Stand, Conversion Gage Gauge Inch/Metric 0-1 Inch/25.4 mm, Digital Probe Dial Test Indicators High Resolution: 0.01mm/0.0005'' https://www.amazon.com/All-Industrial-Tool-Supply-TR72020/dp/B002YPHT76/ref=sr_1_16?crid=1FUE7TOS7NB38&keywords=magnetic+mount+dial+indicator&qid=1659297130&sprefix=magnetic+mount+dial%2Caps%2C282&sr=8-16

Jonny Quest wrote: Some have had good success repairing the CNC props...others not so much.  A $200 repair is half way to a new prop. Tim Benjamin ( TRBenj ) is a long-time CCF contributor and I believe he is an ACME prop dealer.  I've purchased a wheel or 2 from Tim.  Also, Delta Propellers has always been a good prop source.   JQ

Thanks - I think I’m going to lean towards a new one

I used a magnetic mount for simplicity, I had one already, it mounted easy to my prop gaurd and was in a good position to place the dial indicator on my prop shaft.  I recall it was hard to find a place where the taper or the prop key slot was not in the way.  I am sure any mount system could work, some clamp on that would be fine also and if your trailer did not have a prop guard right under the shaft that would be more of a challenge but I think most Nautiques use a prop guard.

MrMcD wrote: With your prop off the shaft you can use a magnetic mount dial indicator and check run out on your shaft pretty quick and know if it is damaged or not.  No reason to lap in your prop and water test.

Great points. I’ve got a drop on a super cheap new prop on CL, really hoping that works out. I’ll look into a dial indicator as well thanks.

Ouch, that hurts.   I had a nice prop damaged, took it in for repair, they charged $260 to repair it.  It ran really smooth but I lost 3 MPH and RPM was higher at all speeds.  I bought a new ACME to fix the MPH loss and it did but now I was out $260 + $400 for the new ACME 422.   Oh well, at least I have a smooth running spare now.   I would not repair it based on my experience.   Prop repairs used to be $100 to $150, but I guess everything goes up now days.

It's fixable, but i would recommend the shaft and strut be checked as well.