priba_euro
New member
Hi fellow boaters
First let me thank you all for this great forum. I've been "lurking" arround this place for more than a year and have found some realy good solutions to my problems.
As all DIYers I'm getting my 2005. BF90A to a best possible condition and been trough repairing all common issues on those engines.
Right now it's power trim/tilt time ... (that might end as separate thread).
Now I'm thinking of one, possibly, extreme job ... trimming off AV plate.
I'm running 16ft (5m) RIB with deep V hull and have raised my OB all the way up. Bracket is 2" above stern.
Since BF90 hight (shaft length) is more than 20" my AV plate is just 1/2" above keel at parallel.
At cruising trim angle (80% out) it's front tip is 1" above keel, back end tip is 3" above keel. That corresponds to 10" setback 1" up.(?)
This position is still deep enough not to blow the prop at this trim angle but if I go max out I get +400 rpm (no speed gain).
At max out trim angle I still get front quarter of AV plate scrapping the surface of water.
I realy don't want to go any higher with OB because at that trim and hight I can blow the prop in turns. If I have it on 80% trim all is good.
So, I would like to avoid that spray from AV plate with max trim out.
Another thing that came to mind is at that condition front portion of AV plate is "digging" a hole that propeller meets further down the line. Right?
I've been searching on the web but couldn't find anyone did that.
Looking at newer OBs all have front part of AV plate much narrower (Suzuki beeing the most extreme in that sence).
Any thoughts or experience is very wellcome.
Thanx in advance
Marko
I'll try to upload some pics (noticed that is problem here ).
First let me thank you all for this great forum. I've been "lurking" arround this place for more than a year and have found some realy good solutions to my problems.
As all DIYers I'm getting my 2005. BF90A to a best possible condition and been trough repairing all common issues on those engines.
Right now it's power trim/tilt time ... (that might end as separate thread).
Now I'm thinking of one, possibly, extreme job ... trimming off AV plate.
I'm running 16ft (5m) RIB with deep V hull and have raised my OB all the way up. Bracket is 2" above stern.
Since BF90 hight (shaft length) is more than 20" my AV plate is just 1/2" above keel at parallel.
At cruising trim angle (80% out) it's front tip is 1" above keel, back end tip is 3" above keel. That corresponds to 10" setback 1" up.(?)
This position is still deep enough not to blow the prop at this trim angle but if I go max out I get +400 rpm (no speed gain).
At max out trim angle I still get front quarter of AV plate scrapping the surface of water.
I realy don't want to go any higher with OB because at that trim and hight I can blow the prop in turns. If I have it on 80% trim all is good.
So, I would like to avoid that spray from AV plate with max trim out.
Another thing that came to mind is at that condition front portion of AV plate is "digging" a hole that propeller meets further down the line. Right?
I've been searching on the web but couldn't find anyone did that.
Looking at newer OBs all have front part of AV plate much narrower (Suzuki beeing the most extreme in that sence).
Any thoughts or experience is very wellcome.
Thanx in advance
Marko
I'll try to upload some pics (noticed that is problem here ).