Specs to reprop a Carver 3207

[Superg]

I have a 1985 Carver 3207 Aft Cabin. I hit something floating beneath the surface in deep water, and despite prop tuning, I still have some vibration from the starboard prop. Prop shop says it should be replaced.

I am looking at getting new Michigan Propeller DQX 4 blades to replace the original Dynaquads. Michigan Propeller needs to know the following information to help with selection.

1. Gear Ratio
2. Max Rated RPM for engines
3. Wide Open Throttle RPM
4. Wide Open Throttle hull speed

Can any fellow owners please help me with these specs? I know that the gear ratio at least is stamped on the transmission, but I am away from the boat at the moment. That said, any help at least on the other specs would be greatly appreciated.

Also, if anyone has experience repropping their older boats with DQX propellers, I would be grateful to hear from you. There are so many options (cupping for example) that it is bewildering.

Kind Regards,
John
Detroit, MI

[jsinton]

Don't know the specifications you seek. What you need is the engine/transmission service manual for your particular engine combination. I only wished to add that I found a great prop calculator that I used to size my new prop that you could play around with: https://www.vicprop.com/displacement_size.php?

[bud37]

Did the shop not balance the prop? If so could it be something else vibrating, just the first thought.

Anyway be careful using factory specs if you can find some, they are done on new boats with no weight in them and fresh engines etc. You already know exactly what your props are and the boats performance with them. I think if you explain your situation to them, you should get the required help.

[Viper]

If the prop shop repaired the prop properly, even to a class 2 repair, it shouldn't be the cause of the vibration. Do they have a Prop Scan unit to scan their repair results? If they do, the printout/graph will show if the repair put the prop back into spec. If they're not confident in their repair or have no way of confirming the spec results after the repair, you may want to take them to a different shop.

Something else could be causing the vibration. Could be anything from; bent shaft, bent strut, bad strut bearing, bad strut alignment, bad engine alignment, warped coupler or tranny flange, or a poor running engine.

[Superg]

thanks. I'll get the results from the prop shop. Had this done through the marina services shop, and they contract out for it, so I'll find out. Had the engines checked and tuned up, had shafts checked. Prop tuning reduced vibration by 70%, but shop said that they were too bad to get perfect and that I would need to think about replacing them. That's when I decided to talk to Michigan Propeller about their new DQX prop.

Unfortunately, I don't have have any third party available to check the validity of the diagnosis at this time and to verify that nothing else might be wrong. Just nobody else around in Port Huron, MI. It's a backwater town. Only other choice is to wait until winter when I bring the boat back down to Lake St. Clair and have another mechanic there check things out.