Merc 400 1971 - Which Propeller?

[nha]

Thanks to the help on this forum, I have my outboard up and running - having replaced the water pump unit... now a new issue... we took it for a test spin this weekend, and the boat hits a certain speed at half mark on the throttle - when we push it forward the remainder of the way we get more revs/power but no more speed? We have been told that this is due to a wrong or slipping propeller - but we have no idea what propeller should be installed i.e. model number, blade numbers etc

Also if anyone has any other input or ideas please do post them - the support here is great!

Thanks

 

[steelespike]

Re: Merc 400 1971 - Which Propeller?

I don't know if I can help with exact size prop but we need more info
to tell better what you need.Boat size and type typical use and load.
There should be numbers on your prop. hopefully something like -- X --
example 11 X 10. diameter X pitch.
As far as your problem you may have a spun hub.Mark across the under side of the hub with an indelable marker run the boat then check the mark
if its split then you have a spun hub.A prop shop can repair it.
Couple of other questions.is the prop in good shape?Is the motor shaft length right for the boat? 15" or 20" Is the antivent plate,just above the prop,about even with the bottom of the boat?

 

[nha]

Re: Merc 400 1971 - Which Propeller?

Thanks for those pointers - the marker idea is a great hint! I'm going to get those numbers and take a few photos this afternoon - I'll post back. Thanks again.