1995 T9.9 ELHT outboard water coolant blockage

[walleye1]

Exhaust cover

[99yam40]

I would be looking at #2 remedy if you do not want to pull the head and ex cover

[MacGregor26D]

Ok thanks. Could you point me to a diagram that shows where the plugs are I should drill and pull out? Not sure I follow you exactly. Thanks

[99yam40]

if Yamaha does not sell them then they will not be in the parts breakdown.
from what Rod wrote they can be seen and removed by pulling the cam cover.

heck I cannot even find the cam cover in the parts breakdown

[walleye1]

Number 35 is the valve cover 99.

[walleye1]

https://cdn.boats.net/MTA/d/3/MjIyNjY4-3c3b5024.png

[MacGregor26D]

Ok that definitely helps to find the cover. Are the plugs that have to be drilled and tapped to be removed obvious after I remove part 35 the valve cover? Sorry if I seem dense but I’ve never experienced this problem before.

[99yam40]

Number 35 is the valve cover 99.

I originally called for valve cover, but Rod said cam cover, so I changed my post also to cam.
the parts breakdown call #35 Cylinder head cover.
I am not sure if that is the same as cam cover

[walleye1]

Cam is on the rear towrd the valve cover

[pstephens46]

Have we discussed taking the motor to a mechanic yet? I quickly scanned this thread. Drilling and tapping plugs that are not available may be a somewhat advanced repair.

[99yam40]

Cam is on the rear towrd the valve cover

I am still confused .
is #35 the cam cover, valve cover, and the cylinder head cover?

I have no idea about what the plugs are made of or their shape.
so making new ones could be challenging I guess until you pull them

[panasonic]

Yam..#35 is all of the above terms you used.

OP if you pull the valve, cam, head cover, whatever you want to call it, #35, take a picture of the inside and post it here the blanking plugs can be pointed out to you. If you drill them out then you will have to get a machine shop to make you new ones to put back in.

OR remove the head to get at the passages. I think that is what Rodnut is saying. He also says the exhaust cover has to come off.

I would remove the exhaust cover first and see how much crap is built up in there first then proceed from there.

I am not saying Rod is wrong but it could be a chunk of rubber jammed in one of those little passages if that engine has eaten an impeller in the past. I have had the pleasure of dealing with that on a F9.9 once. But it was mostly a fresh water engine and pretty clean inside.

[MacGregor26D]

Thanks for all the help! You guys are great and I appreciate your input. The suggested repair may be beyond my current skill set and I’m talking with a friend that’s more mechanically advanced to help with the remedy. I’ll let you know the outcome.

[rodbolt17]

if you can walk and chew gum this repair is simple.
\you remove the cover.
on the port side you will see two nickel sized plugs.
use a 7/32 drill bit and pop a hole in about the center.
tap it 1/4x20.
use a 1/4x20 bolt.
screw a nut all the way up it.
place a fender washer on it.
thread it in the plug.
hold the bolt head.
turn the nut down and the plug comes out.
easy peazy.
nope it aint taught in school and 99% of Yamaha techs aint got a clue how to do it.
only those of us with 30+ yrs of tinkering and incredibly lazy can do this.

[MacGregor26D]

Thanks rodbolt. After blowing a LOT of air and water through her she started to flow nicely in a barrel. Perhaps a long shaft needs more water or the extra purge helped. Have to pull the valve cover anyway to check the valve clearances as she is running a little rough beyond idle. Thanks to all for your help. I’ll be asking more questions I’m sure