We have the 2010 with 120S saildrive
on our maxi
77. We have 4500 lbs displacement
and 8 foot beam. With the original folding prop we saw about 3.5 kts @ 2500 RPM
. We never really ran higher because it passed our onboard noise
tolerance level. We could probably get 3.7 @ 2800.
Reverse performance was pretty dismal. We were given a duo-prop feathering prop and it has really transformed the boat. At 2500 we get about 5.8 kts. We can just about get to 6 at 2800. We now normally cruise
at 2200 at about 4.5 kts.
I really can't exptrapolate on your boat's performance but I can say that the prop is the single
most important factor.
has been pretty trouble free. We have had several days of 8+ hours of motoring (don't ask)
Here is what I would check.
1/ Impeller - when was it last changed - Ours failed
2/ If the oil
has not been changed I would pull the oil filter
and cut it open to look for chips.
3/ I would inspect very carefully around the saildrive
seal. I am sure ours is seeping and it's on the list for a replacement.
mounts. Check the mounts at idle both in and out of gear
. Worn mounts will allow "excessive' shaking - ours are due with the new SD seal.
mount and belt - Our belt was slipping. I had it tensioned once by someone else and it soon slipped again. I changed the belt and tensioned it myself and so far (about 20 hours) so good.
6/ As for any engine I would check for oil
in the water
in the oil, external oil and water leaks
Oh, and we ran our engine for 4 hours as part of the sea trial and eyballed water and oil consumption