Honda BF30A Replacement Props

[Siantis]

Hi,

Currently I'm running a Honda BF30A engine, with a 3 blade, 9 1/4 diameter, 12 pitch prop. The boat is an AVON 4.7m (15/16 foot) flooding hull RHIB.

I'm having trouble getting the boat up on a plane. On rare occasions (flat calm or running with the seas) I can get the boat up. However, the majority of the time I cannot even when the boat is loaded differently.

Honda lists 9 7/8 diameter props with 9, 10, 11, 12 and 13 pitch. Would a reduced pitch help? And would the (slightly) larger diameter do much?

BTW: I do not have a tachometer available at current.


Thanks in advance!

 

[pwiseman]

Re: Honda BF30A Replacement Props

Hi,

Currently I'm running a Honda BF30A engine, with a 3 blade, 9 1/4 diameter, 12 pitch prop. The boat is an AVON 4.7m (15/16 foot) flooding hull RHIB.

I'm having trouble getting the boat up on a plane. On rare occasions (flat calm or running with the seas) I can get the boat up. However, the majority of the time I cannot even when the boat is loaded differently.

Honda lists 9 7/8 diameter props with 9, 10, 11, 12 and 13 pitch. Would a reduced pitch help? And would the (slightly) larger diameter do much?

BTW: I do not have a tachometer available at current.


Thanks in advance!

I had that same motor and a similar boat. I ended up switching between 10 and 12 pitch depending on load. 12 was great with just me, 10 was fine for 2 or 3 people. I also tried a stainless 11 pitch, but the balance was off and cupping made the boat troll too fast. I would stick with oem aluminum prop. Pay more attention to the pitch than the diameter. Actually, a smaller diameter will do you more good than larger diameter if you are underproped. They must have recently added the 11 pitch, as I looked for that a couple years ago. Realistically, if the 12 gives you that much problem planing, the 10 is probably going to be a good fit. Just be carefull to make sure you don't over rev when you drop pitch. I found that lower pitch helps a great deal with planing, but if you are low on HP for the boat, you can redline pretty easy after you plane. I would get a tach, althought the Honda should have rev limiter on it.

 

[rndn]

Re: Honda BF30A Replacement Props

Have a marina put a tach on it and tell you what the rpm's are at WOT. You could cause severe damage by depropping without knowing this very imprtant piece of information. Unless you have plenty of disposable income and want to justify a new motor to your significant other, don't pass on this very important step. A marina may even do it for free if you plan to buy your prop from them or have had other service done by them.

 

[Siantis]

Re: Honda BF30A Replacement Props

Thanks for the help guys.

I guess I'll try to get a tach and see what it's running at with the current prop.

 

[Siantis]

Re: Honda BF30A Replacement Props

Sorry for the double post, but can anyone recommend a good (hopefully cheap) tachometer? Do you just hook the tach up to the spark plug wires on the engine?

The engine is tiller driven, so no instrument panels.

 

[pwiseman]

Re: Honda BF30A Replacement Props

Sorry for the double post, but can anyone recommend a good (hopefully cheap) tachometer? Do you just hook the tach up to the spark plug wires on the engine?

The engine is tiller driven, so no instrument panels.

Honda tach is bit tricky but not bad to hook up. On tiller model, there is a rubber plate under the end of the tiller. YOu have to open that up and pull out the tach leads. The wiring diagram I got with my honda was a bit weak as all the colors were not exactly as marked. You do need to take care to get one that is specifically matched to your honda. They have them listed on hondamarine.com so you should be able to get the part number.

 

[bigtwin]

Re: Honda BF30A Replacement Props

www.tinytach.com/

 

[Siantis]

Re: Honda BF30A Replacement Props

I like the those TinyTachs, but I'm confused as to what model to purchase. I'm not sure of the spark firings per revolution. I tried emailing them, but haven't received a reply...