Twin drives are level but the indicators are way off...
#1
Registered
Thread Starter
Join Date: Nov 2005
Location: Pittsburgh, PA & Marco Island, FL
Posts: 539
Likes: 0
Received 0 Likes
on
0 Posts
Twin drives are level but the indicators are way off...
OK Guys,
While the boat's on the trailer this week I thought I'd mark the trim tabs and drives at the 'level' or 'neutral' position.
The trim tabs come right in at '5'.
The drives, on the other hand, are another matter. The starboard drive is neutral at '4' but the port drive is neutral at '3'. I got out of the boat and checked them three times.
Is this within spec? I have a hard time believing that there isn't an adjustment that needs to be done. If so, is it something I can do myself? Does it have something to do with the trim rams?
I don't want to have to remember to trim the port drive up a whole # when I've got enough on my mind driving the boat!
Also, my boat has always listed to port while on plane. Do you think this might be why?
While the boat's on the trailer this week I thought I'd mark the trim tabs and drives at the 'level' or 'neutral' position.
The trim tabs come right in at '5'.
The drives, on the other hand, are another matter. The starboard drive is neutral at '4' but the port drive is neutral at '3'. I got out of the boat and checked them three times.
Is this within spec? I have a hard time believing that there isn't an adjustment that needs to be done. If so, is it something I can do myself? Does it have something to do with the trim rams?
I don't want to have to remember to trim the port drive up a whole # when I've got enough on my mind driving the boat!
Also, my boat has always listed to port while on plane. Do you think this might be why?
#3
Charter Member #34
Charter Member
Join Date: Oct 2000
Location: Beautiful North Carolina
Posts: 7,151
Likes: 0
Received 1 Like
on
1 Post
Re: Twin drives are level but the indicators are way off...
Originally Posted by cbeastwood
Also, my boat has always listed to port while on plane. Do you think this might be why?
Yes, that is definately why. I had the same problem a couple of years ago.
Both indicators and both drives should line up perfectly.
The easiest adjustment is to loosen the indicator and slide it on the cylinder of the drive until you have the reading on the guage that you want at that drive position.
Hopefully you will not have to mess with the cable adjustment up at the helm. That is a pain.
Good luck.
#4
Registered
Join Date: Feb 2006
Location: Tomball (Houston), TX
Posts: 482
Likes: 0
Received 0 Likes
on
0 Posts
Re: Twin drives are level but the indicators are way off...
I have similar issues too. I don't know if it's an optical illusion but when my drives are all the way down, it appears the port drive goes down just a little bit farther (looking at the drives not the gauge). I think tonight I'll get a measuring tape and a level out to confirm but if one drive does go down farther than the other, is there an adjustment for this? Is this what the little round hockey-puck looking senders are for on the side of the drives? I have a Mercury Manual that is for all Bravos, I guess I'll have to give it a good read.
Another issue I have is with the throttles. With the throttles pulled back at idle, my rpms are the same between motors. The rpms are also the same between motors at full throttle but at half throttle or close to half throttle, the starboard motor will read about 3700 rpms, and the port will be around 3500 rpms so I've been pushing the port throttle a little further forward than the starboard stick to get even rpms at cruise. My thoughts are this is probably just a throttle cable adjustment. My other thought is maybe the drives really aren't level and this is causing the variance. I guess the first thing to do is make sure the drives are level before I start looking for throttle cable adjustments.
Thoughts, comments?
Thanks in advance!
Chris
Another issue I have is with the throttles. With the throttles pulled back at idle, my rpms are the same between motors. The rpms are also the same between motors at full throttle but at half throttle or close to half throttle, the starboard motor will read about 3700 rpms, and the port will be around 3500 rpms so I've been pushing the port throttle a little further forward than the starboard stick to get even rpms at cruise. My thoughts are this is probably just a throttle cable adjustment. My other thought is maybe the drives really aren't level and this is causing the variance. I guess the first thing to do is make sure the drives are level before I start looking for throttle cable adjustments.
Thoughts, comments?
Thanks in advance!
Chris
#5
Registered
Re: Twin drives are level but the indicators are way off...
I can fix all of your problems for each of you.........................
Smash the throttles all the way forward and then trim your drives all the way out................LET IT RIP.
Smash the throttles all the way forward and then trim your drives all the way out................LET IT RIP.
#6
Charter Member #34
Charter Member
Join Date: Oct 2000
Location: Beautiful North Carolina
Posts: 7,151
Likes: 0
Received 1 Like
on
1 Post
Re: Twin drives are level but the indicators are way off...
Originally Posted by Busta
Another issue I have is with the throttles. With the throttles pulled back at idle, my rpms are the same between motors. The rpms are also the same between motors at full throttle but at half throttle or close to half throttle, the starboard motor will read about 3700 rpms, and the port will be around 3500 rpms so I've been pushing the port throttle a little further forward than the starboard stick to get even rpms at cruise. My thoughts are this is probably just a throttle cable adjustment. My other thought is maybe the drives really aren't level and this is causing the variance. I guess the first thing to do is make sure the drives are level before I start looking for throttle cable adjustments.
Thoughts, comments?
Thanks in advance!
Chris
Thoughts, comments?
Thanks in advance!
Chris
But the more you trim your drives out the higher RPM you will see.
So you really do need to make sure the drives are synchronized with each other.
I'm leaning more toward cable adjustment in your case, since 200 RPM at mid throttle is a lot.
For what it is worth, I driven more twin setups where the throttles did not line up perfectly at the same RPM then ones that do.
Good luck
#8
Registered
Join Date: Feb 2006
Location: Tomball (Houston), TX
Posts: 482
Likes: 0
Received 0 Likes
on
0 Posts
Re: Twin drives are level but the indicators are way off...
Thanks Doc! I thought I was on the right track with my thinking but having an experienced pro like yourself confirm makes me feel even better. Have a great weekend!
#10
Charter Member #34
Charter Member
Join Date: Oct 2000
Location: Beautiful North Carolina
Posts: 7,151
Likes: 0
Received 1 Like
on
1 Post
Re: Twin drives are level but the indicators are way off...
Originally Posted by Busta
Thanks Doc! I thought I was on the right track with my thinking but having an experienced pro like yourself confirm makes me feel even better. Have a great weekend!
Busta,
I always very glad to help when I can. I have been on this site since 1999 and everything I have learned came from the good folks here.
BajaRunner brings up a good point on props also.
And speaking of props, wish me luck. SteelOutlawed is going to come up tomorrow and help me teat a new custom set of 29's and I hope to break the 80 MPH mark!
Dock