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BF225 '06, lower unit bolt is loose

PhatFireMan

PhatFireMan

Member
Need advice,


I just bought a used boat, has a 2006 Honda BF 225hp outboard on it, 250 hours, runs great, haven't used it since the sea trial last week. I was detailing the boat today and noticed that one of the three bolts, on the port side of the outboard, that mount the lower unit to the mid-section, is slightly backed-off, about two threads worth.


The only reason I caught this is because as I swept my hand over it, the washer made a little rattle noise. The bolt is not "loose", I cannot turn it with my fingers, but it is not fully seated. I cannot see any gear oil seeping out from the lower unit seam at this time.


Before I put a socket on it and cinch it up, I wanted to be sure that there is not some sort of torque pattern on the lower unit that I am messing with, or sealant inside the bolt hole of some kind, etc.


Anybody know if I can just go ahead and turn it? If so, anybody know the torque setting by chance?


Any ideas on why this occurred and what might be going on as a result?


I have not had the chance to release a drop of lower unit oil yet to check it for milky-ness. Will do that tomorrow.


Thanks,
Kris
 
Bolts should be flush. Torque is 25 ft lbs. When you drop the lower unit, don't forget that one of the bolts that holds the lower unit in place is the bolt that holds the trim tab. So when you remove it, note the angle of the trim tab so that you can put it back where it was.

As a new owner, I highly recommend that you invest in a Helm shop manual for that motor. They are pricey at $116.oo, but well worth the money. Do not use one of the after-market manuals. They have a lot of errors.
 
A loose lower unit attach bolt will not allow water to get into the gearbox, if that's what you're worried about. I'd remove the bolt, check threads for corrosion or cross threading, look at the threads in the lower unit with a light and inspection mirror. A little anti seize on the bolt, then install & torque, as CHawk said. If the bolt bottoms out before it seats, you either have a wrong length bolt or a mis-machined threaded hole.
 
I had the boat in this morning at Jeff's Marine in Oxnard for some seller-paid-for minor repairs that were part of the deal, while it was there Jeff was able to remove the lower unit bolt for me. He worked it back and forth a bit, then all the way out.


The bolt was slightly galled, not cross-threaded. He ran the threads with a dye and put it back in with a dab of marine grease. Then he did the same with all the other lower unit bolts. Specialty Marine, who did the last impeller service, failed to use any anti-seize, or even grease, on the threads of any of the lower unit bolts. Lame.


Jeff is a real nice guy and does solid, honest work. I will definitely go back to him. I will definitely NOT be going to Specialty Marine any time soon.


Problem solved. Thanks everyone for the input!
 
The 225 impellers are easy to replace. If yours is a long shaft model, You should also check-replace the mid-shaft driveshaft bushing and clean any deposits in that area before they distort the bushing and kill your driveshaft. (see other posts on this subject). The manual will pay for itself after one use if you can do this without taking it to a dealer.
 
One other thing you should know about that engine. Every time you pull a 100-hour maintenance, pull the plugs and inspect them, then whether to but them back in, or new ones, coat the threads with marine anti-seize grease. If you leave them in for the recommended 400 hours, they are likely to seize to the head, then you have a real mess on your hands.
 
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