waterway1
New Member
i have a birchwood 22 with a volvo 115hp petrol engine and volvo leg. when i bought it i was told she would do 17 knots but i cannot get more than 7/8 knots. is this right or am i doing something wrong?
birchwood 22
- Thread starter waterway1
- Start date
boatmaster
Well-Known Member
17 knots seems a optimistic to me with the age of the boat but i've known them do more than 9K with that engine, may be worth checking your propellor and taking advice to ensure the size and pitch is correct for higher speeds, she may have a river prop on.
GRPrich
Member
We had a birchwood 22 with the same engine/outdrive set up a some years ago and when we bought it, it wouldnt do anymore than 7 knots at best!
We had the boat lifted out for an antifoul and engine/outdrive service and after relaunch it made 16 knots so a big difference.
I would be looking at the state of the antifoul or condition of your prop, followed by a full service and see how the boat performs afterwards.
Maybe try adjusting the trim tabs if fitted to your boat (ours had manual adjusting tabs) and after alot of fiddling about did make a difference.
Also take into consideration what weight/gear on board as the 115hp isnt a great deal of power to play with, so things that can be removed from the boat to save weight will be beneficial.
Hope this helps! Rich
We had the boat lifted out for an antifoul and engine/outdrive service and after relaunch it made 16 knots so a big difference.
I would be looking at the state of the antifoul or condition of your prop, followed by a full service and see how the boat performs afterwards.
Maybe try adjusting the trim tabs if fitted to your boat (ours had manual adjusting tabs) and after alot of fiddling about did make a difference.
Also take into consideration what weight/gear on board as the 115hp isnt a great deal of power to play with, so things that can be removed from the boat to save weight will be beneficial.
Hope this helps! Rich
Jim@sea
Well-Known Member
When its doing this 7-8 knots how many revs is it doing.
waterway1
New Member
waterway1
hi thanks to all of you for the advice. sorry i didn't reply before but my computer caught flu and then gave it to me. i have now spoken to a boat engineer and am going to take the prop to him to measure the pitch and see if any help can be had there. she is now on dry land and will be antifouled so that may help, she did have a fair coating of barnacles on her when she came out. lastly the engine is doing 3500 revs to get 6/7 knots. once again thanks for the help.
hi thanks to all of you for the advice. sorry i didn't reply before but my computer caught flu and then gave it to me. i have now spoken to a boat engineer and am going to take the prop to him to measure the pitch and see if any help can be had there. she is now on dry land and will be antifouled so that may help, she did have a fair coating of barnacles on her when she came out. lastly the engine is doing 3500 revs to get 6/7 knots. once again thanks for the help.
PaulGooch
Well-Known Member
6/7 knots is about right for your hull speed, so unless you can get her on the plane, that's yer lot.
hlb
RIP
Think I'd be inclined to just accept the 8 knot. If you ever managed to improve on it, it would cost more than the boat.
Give the botttom a scrub and clean the prop, it will be far more cost effective than anything else you can do.
Give the botttom a scrub and clean the prop, it will be far more cost effective than anything else you can do.
oldgit
Well-Known Member
As a comparison my 25ft Princess 25 with 175hp petrol V6 would just about do 17 knots on a good day,get a few peeps on board and 12/13knots was the order of the day.
