Posted by matthew schoenste on 09/11/10 - 6:40 PM
#1
i recently purchased a used 2001 25hp 4 stroke yamaha w/tilt and trim for my 13 ft'er. it runs perfectly, well almost. this is my first yamaha and im not all that familiar them and any motor features it may have that im not used to. so anyway my problem is when i trim my motor up and begin to accelerate my trim basicaly loses its hold and drops back down again and im not able to trim it while moving neither, although i can hear the motor trying to trim. i do have a little gray area though. and that's when im first accelerating like up to 5mph maybe? it doesn't drop out and i can trim the motor, but once i hit that threshold it drops. and it seems like the threshold is the same every time thats why i think it just may be how the motor is desinged and if thats the case, i have a 2001 yamaha for sale. if i could get the motor to trim on demand at any speed like i expect it should then that boat would run perfect. any info or help on this would be much appreciated.
Posted by Ice Cop on 09/11/10 - 10:31 PM
#2
MY GUESS WOULD BE A LOW OIL CONDITION THOUGH I HAVE NEVER OWNED A YAMAHA. EVINRUDE USES A HYDRAULIC SYSTEM TO TRIM THE ENGINE AND A LOW OIL LEVEL WOULD CERTAINLY CAUSE THOSE SYMPTOMS
Posted by DownTonset on 09/12/10 - 12:33 AM
#3
Ice Cop's solution (making sure the fluid level is correct) is the most obvious, and definitely the first one you should try. If the problem persists, however, it's likely that your hydraulic system is compromised somewhere. Make sure your manual release valve is not loose or leaking, first of all. If not, based on the symptoms you describe, the next suspects on my list would be a faulty "up" check valve or a bad o-ring, in that order.
I put a lot of hours on the two Yamaha outboards I have owned in the past (S115 and 40 h.p. 2-stroke) and the only problems I ever had with either one of them were related to the tilt units. Seems like something of an Achilles' heel for Yammie.