I have a 1993 F35 with a Martec 3-blade folding prop and a 27 HP
Yanmar 3GMF engine. In flat water at cruising RPMS (2800-2900) I’m
getting just over 5 kts of speed. In a head wind with some seas I’m
cruising in the mid to high 4 kts range. I would expect much more
from a boat of this size.
I’d be interested to know what other F35 owners are seeing for a
cruising speed under power to know if what I’m experiencing is
typical or not.
I suspect the prop pitch is not set correctly. The engine comes up
to RPMs quickly and without much effort. So I don’t think it is over-
loaded. Does anyone have experience modifying the prop pitch on a
Martec prop? Is this a DIY job or does it require a specialized
mechanic?
I have a 1996 F35 and just put on a KIWI feathering
3 blade prop. I am getting 6.5 kts at 2800. I loose a few tenths of speed
into a 15 kt head wind. The boat has sat for over two months so the bottom has
a bit of growth and in spring when everything was clean I had another ½ knot of
speed at 2800. My prior two blade folding prop would loose 1 to 1 ½ kts into
the same wind.
I have a 1993 F35 with a Martec 3-blade folding prop
and a 27 HP
Yanmar 3GMF engine. In flat water at cruising RPMS (2800-2900) I’m
getting just over 5 kts of speed. In a head wind with some seas I’m
cruising in the mid to high 4 kts range. I would expect much more
from a boat of this size.
I’d be interested to know what other F35 owners are seeing for a
cruising speed under power to know if what I’m experiencing is
typical or not.
I suspect the prop pitch is not set correctly. The engine comes up
to RPMs quickly and without much effort. So I don’t think it is over-
loaded. Does anyone have experience modifying the prop pitch on a
Martec prop? Is this a DIY job or does it require a specialized
mechanic?
When I put the boat in last spring my top
end increased about .5 kts. Where I noticed the difference was at lower
rpm’s where I picked up a knot of speed and when motoring into a head sea
or high winds the through the water speed would not drop off. Also with
the feathering prop I now have great stopping and backing power. I’m
a big fan of the KIWI prop, they have a web site. Its pitch is adjustable
and I can get a max rpm of 3400 so I am pleased with this setting. I have
done the ICW with my old 2 blade folding prop and needed 3000 rpm to hold a 6
kt speed. I would expect I can now do 2700 rpm and get 6 to 6.5, with a
clean bottom.
The Kiwi looks like an excellent product at a very good price for a
feathering prop. Just remember that it’s only rated up to around 50
hp, so people with larger freedoms may be out of luck at this time.
When I put the boat in last spring my top end increased about .5
kts. Where
I noticed the difference was at lower rpm’s where I picked up a
knot of
speed and when motoring into a head sea or high winds the through
the water
speed would not drop off. Also with the feathering prop I now
have great
stopping and backing power. I’m a big fan of the KIWI prop, they
have a web
site. Its pitch is adjustable and I can get a max rpm of 3400 so I
am
pleased with this setting. I have done the ICW with my old 2 blade
folding
prop and needed 3000 rpm to hold a 6 kt speed. I would expect I
can now do
2700 rpm and get 6 to 6.5, with a clean bottom.