312 fastech throttle trim problems
03-12-2007 | 01:23 PM
#11
Registered
Joined: Oct 2006
Posts: 163
Likes: 0
From: San Jose, CA
My 'once in a while' trim problem fired up with a vengeance this weekend, the first nice weekend of the year, too.
Now neither the dash trim switch or the throttle trim switch will raise the port-side outdrive. Trailer switch works, though, so at least I wasn't dead for the weekend, but it is frustrating.
Where is the drive limit sensor located? Is it something I can repair\replace, or is it best left to the dealer?
Now neither the dash trim switch or the throttle trim switch will raise the port-side outdrive. Trailer switch works, though, so at least I wasn't dead for the weekend, but it is frustrating.
Where is the drive limit sensor located? Is it something I can repair\replace, or is it best left to the dealer?
03-26-2007 | 12:20 PM
#13
Registered
Joined: Oct 2005
Posts: 356
Likes: 0
From: Lake of the Ozarks MO
My 'once in a while' trim problem fired up with a vengeance this weekend, the first nice weekend of the year, too.
Now neither the dash trim switch or the throttle trim switch will raise the port-side outdrive. Trailer switch works, though, so at least I wasn't dead for the weekend, but it is frustrating.
Where is the drive limit sensor located? Is it something I can repair\replace, or is it best left to the dealer?
Now neither the dash trim switch or the throttle trim switch will raise the port-side outdrive. Trailer switch works, though, so at least I wasn't dead for the weekend, but it is frustrating.
Where is the drive limit sensor located? Is it something I can repair\replace, or is it best left to the dealer?
03-27-2007 | 08:39 PM
#14
Registered
Joined: Jul 2001
Posts: 1,074
Likes: 2
From: Holland, Mich
the trim limit switch is teh black puck on teh left side of each drive. it has a range that allows continuity and a range that does not. this alows you to trim only to the max tim before excessive angles on the u joint.
you can adjust this stop point by loosening the two screws on the limit puck and rotating slightly until you reach the proper max angle.
I adjsuted both of mine to be the best trim for top speed run on a smooth day ( this was less than the max trim specification)
let me just hold both trim buttons without watching he indicator gages. they stopped right where I want them to.
there is a specification by mercruiser for the max dimension from the two bolts on the trim cylinders. make sure you do not exceed this.
the issue can be a bad limit switch, or mis adjusted, or swithc issues as discussed above.
however..... this issue can be an indicator of another issue.
on both of my bravo drives . I found that the pivot bolts behind the pucks had rotated. ( resulting in a mis adjsutment of the limit puck)
sometimes you can just retighten them ( 50 or 90 ft0lbs) check the mercruiser service manual
but. on two of mine the bolt actually stripped out. The solution is a stainless helicoil kit. I have replaced two threads, and loadned out the tap adn isntaller kit to three other OSOers now ( actually someone never sent it back to me.....)
so checc the bolts behind the pucks.
then have someone hold the trim button and slowly rotate the puck to see if it will complete the circuit, then yo ucan fine tune to get the final trim ram extension.
Ramb
you can adjust this stop point by loosening the two screws on the limit puck and rotating slightly until you reach the proper max angle.
I adjsuted both of mine to be the best trim for top speed run on a smooth day ( this was less than the max trim specification)
let me just hold both trim buttons without watching he indicator gages. they stopped right where I want them to.
there is a specification by mercruiser for the max dimension from the two bolts on the trim cylinders. make sure you do not exceed this.
the issue can be a bad limit switch, or mis adjusted, or swithc issues as discussed above.
however..... this issue can be an indicator of another issue.
on both of my bravo drives . I found that the pivot bolts behind the pucks had rotated. ( resulting in a mis adjsutment of the limit puck)
sometimes you can just retighten them ( 50 or 90 ft0lbs) check the mercruiser service manual
but. on two of mine the bolt actually stripped out. The solution is a stainless helicoil kit. I have replaced two threads, and loadned out the tap adn isntaller kit to three other OSOers now ( actually someone never sent it back to me.....)
so checc the bolts behind the pucks.
then have someone hold the trim button and slowly rotate the puck to see if it will complete the circuit, then yo ucan fine tune to get the final trim ram extension.
Ramb
03-28-2007 | 10:43 AM
#15
Registered
Joined: Oct 2006
Posts: 163
Likes: 0
From: San Jose, CA
Took the limit switch\sensor apart on on the port drive and it had some corrosion on the contacts. Cleaned it up, re-assembled with some dielectric grease, and now works perfectly. Also gave me the chance to teak the adjustment so that both drives now top out at exactly the same level.
30 minutes of work and cost me nuthin' but labor. Thanks for all the advice.
30 minutes of work and cost me nuthin' but labor. Thanks for all the advice.
