1994 Yamaha C85TLRS 2-stroke outboard moves front to back

[John G]

I've got a 2-stroke Yamaha 85HP outboard that seems to have a lot of play front to back.  If you stand in the boat facing the stern and grab the motor, you can push it a few inches back and towards you.  Is this normal?  I have checked the mounting to the transom and the bolts are all tight. Research keeps pointing me to "motor mounts", but looking in the repair manual it seems to point towards mounts that are somewhat connected to steering?  The Yamaha dealer has been absolutely no help other than telling me to bring it in.   Any thoughts?

[wingnut]

Without seeing a photo, sounds like the lower mount which attaches the trunk/housing (mid-section, upper casing, whatever you want to call it) to the actual tilt assembly may have broken free. This can happen if you hit a rock or drag the skeg, etc. and the tilt arm bolts pull out of the upper casing, or break a chunk off the casing. Either way, the casing is usually toast.

Google image search "yamaha upper casing" and you'll see a spot towards the bottom/front where the tilt arm grabs the casing. Check this area for something broken or loose. Not always easy to see, since it's covered by the U-shaped clamp.

I had Yamaha 50 that had a similar problem when I got it (came as a freebie), and I found a used upper casing on eBay for $80. It is not a bad repair, you just have to drop the lower unit, unbolt the old casing, and bolt the new one on.

Whatever the case, I would look at the lower attachment to the housing, not where the motor connects the transom. The motor is fully supported by the tilt/trim assembly at the transom but stabilized by the lower connection to the housing.

[wingnut]

But no, your motor should not move by hand like that!

[John G]

Thanks for the help. I will definitely check that out this weekend. I bought the boat a few weeks ago and the motor runs great other than some vibration at low RPM and this movement issue, which I'm now thinking could be part of the vibration issue.

[wingnut]

Unfortunately that is an easy issue to hide when a boat is sold. Would definitely explain the vibration (at higher speed, the motor is pinned towards the transom and wouldn't be able to wobble as much). If it is indeed broken at the lower connection I would be very cautious about running it.

[boatnamesue]

Remove the upper cowling and push/pull the lower cowling.....does the engine move with the lower cowling or just the cowling move?

[John G]

Well, I did some investigating this weekend and really didn't figure much out.  I looked everywhere for something broken and can't find anything. When you grab the casing the entire engine can move forward and back an inch or two, including the lower unit. I did notice that when the motor goes up into tilt/trailer position, it slides forward a bit when tilting.  Something has to be loose on the mounting..  Are there rubber bushings inside that have possibly worn out?

[wingnut]

Did you happen to take any photos? Where in Maine are you located?

[John G]

No, I forgot to bring my phone with me.  Boat is in Boothbay.

[boatnamesue]

The engine is mounted on the lower pan, of course....and I reckon there are bushings in between the engine/pan.  But I'm puzzled here as to why the mid and lower sections are moving...photos and video would be helpful, when you get back to the boat. 

Until then, I recommend joining www.yamahaoutboardparts.com forum.  There are a number of master Yam mechanics on the forum who could help.  Membership is free.  Once signed up just start a new thread, provide full model/yr/hp, and describe what you've detailed here.  Good luck!

[Mwar410]

There are upper and lower bushings on the steering assembly (shaft) they can cause the engine to pivot forward and back. They’re nylon split bushings

[John G]

There are upper and lower bushings on the steering assembly (shaft) they can cause the engine to pivot forward and back. They’re nylon split bushings

I picked up a repair manual and that's what I'm leaning towards, but I'm having a hard time wrapping my head around it without actually seeing it assembled.  The book is great unless you don't know what you're looking at 

It looks to me that it will be a winter project to get at the bushings.   Thanks for the help everybody!

[John G]

So...   I'm now thinking about picking up a used outboard for this boat (2008 Mercury Optimax 115hp) , then repairing the mounts on this Yamaha and selling it.  The 2 main questions I have are - how do I know what shaft length is needed for this boat, and if enclose the transom and put the motor on a plate does that give me options?   Boat is a 1973 19-6

[Mwar410]

It was originally set up for a 20” shaft. If you’re planning on raising or replacing the transom, I would go with a 25”. I mocked up my 196’s transom and even with a 10”  setback on my jack plate, I’d still have to put a splash well in a full transom.

[John G]

So... I finally got the boat in the garage and the motor off the boat. I have the Seloc repair manual but it doesn't have any information on how to access these bushings. After watching some youtube videos (other models) I see these bushings are accessed by removing the powerhead.  I started taking the motor apart over the weekend to get at these upper bushings and ran into a major snag.  When I removed the long powerhead bolts I noticed some brown goop all over them.  There is also a bunch of it all around the seam where the powerhead separates from the lower portion.  I have the feeling someone had it apart and used Indian Head sealer or something similar on the gasket and now I can't get it apart!   I've got a hoist putting tension on the lift hook and I've been scraping at the gasket trying to see if I can get a weak spot, but after 2hrs I gave up.  I don't want to mess up the aluminum. Any ideas?