2007 Yamaha 9.9 2 Stroke Diagnosis

[virginiaviking80]

Hi there,


I'm new to boating and have been experiencing some potential issues with my Yamaha 9.9 2 stroke. I bought it used (new impeller was claimed to have been installed) and have taken it out a dozen or so times. There were no noticeable issues for the first few trips. A few trips ago, my mind was elsewhere and I started the engine to flush it without having the muffs attached. It ran for between 15-30 seconds before I noticed it and shut it down. I was concerned there may have been some impeller damage but ran it some more with muffs, as well as on a following short trip on the water; tell-tale felt warm (maybe warmer than normal but the sea temp had warmed up), even when opening up the throttle so i thought I was good to go. The next trip, I did something even more stupid and unknowingly launched the skiff with the muffs on. I didn't know this for a while and ran the boat around on a fast idle at the ramp, checking the tattle tale and engine for any problems. It felt fine just warm so I opened up the throttle and took off. Well, the muffs slipped off and the v part of the muffs slipped down the lower unit; skiff pretty much stopped immediately. The engine wouldn't shift into forward but reverse worked fine (didn't know why at this point) so i paddled it back to the ramp and loaded it up. Once I inspected the motor out of the water, I noticed my error with leaving the muffs on and saw some small nicks along the base edges of the propeller blades. I did not originally think this damage was significant (see attached photos) but would be interested to get more opinions on this. I have watched the propeller blades spin at an idle out of water and the rotation looks smooth.

Finally, I took the boat out today. Everything was running well at the ramp, as well as when I pulled away at a fast idle. Tattle tale was pretty warm, especially right at start up but did not concern me. I ran pretty close to wide open for about half a mile before meeting the mouth of the creek I was headed to. At this point, I noticed a good amount of clear/whitish steam/smoke coming out of the left side of upper unit; no smoke or gas smell that I could tell. The water was very hot coming out of the tattle tale; I could hold my hand there without burning so it wasn't boiling but it was definitely too hot. I dropped the engine to an idle and the smoke/steam and water temp disappeared quickly. I decided to keep running the boat on idle/fast idle and keep fishing to further assess the issue. I did not experience anymore problems on the water, including when I carefully ran the boat back to the ramp well above fast idle. I think the tattle tale was still warmer than usual but not hot and no more smoke/steam. At no point, have I ever heard a buzzer/alarm go off. When I got home, I flushed and emptied the engine as usual. Tattle tale was still warm with good flow. Lower unit and upper unit were not unusually warm. However, upon feeling on the lower unit, there was some very hot water trickling out above the antiventilation plate(see attached); don't know what these ports are called and I have honestly never checked them before but I assume hot water in this area is not normal.

I want to inspect the motor and deal with the problem myself but I'm a noob and would greatly appreciate any help on ways to troubleshoot and fix whatever it is before it becomes a bigger problem. Due to my aforementioned mistakes, I am thinking that the impeller/water pump needs to be replaced, some work done to the propeller or replaced altogether , and our some dirt/sand needs to be removed. Another possible concern is the poppet valve and thermostats but not too sure about its pertinence to my symptoms. Below is a quick summary of the things I've noticed:

* Very hot water and clear/whitish smoke/steam coming out of the port side of the motor after running the motor half a mile at high rpm; could not replicate the issue when running the boat at high rpms (but not as high) a little later
* Hot water coming out of ports above the antiventilation plate when running the motor on muffs, after returning home
* Tattle tale has been running pretty warm compared to sea temp
* Tattle tale flow has always appeared adequate
* Edge nicks on propeller blades
* Tattle tale sometimes takes as long as 15 seconds to produce when starting the engine up

Any advice or thoughts before I start taking things apart would be great. If you made it all the way through this email, thanks so much for reading!

https://imgur.com/a/ZKIhc

 

[99yam40]

pull an inspect water pump to see if you can see any damage/.
pull and test thermostat, and inspect the water passages around it

 

[virginiaviking80]

I pulled off the lower and sure enough, an impeller blade broke off and was partially blocking flow. However, I struggled for quite awhile trying to reattach the lower unit. I removed the lower with the gear in neutral. While i was trying to reattach the shift linkage, the shift linkage rod from the lower end did not sit passively with the linkage collar. I adjusted the collar to make it work and after reassembling multiple times, the gears would not shift into forward or reverse. I decided to manually set the lower unit shift rod into the minimum position (presumably reverse), as well as the gear into reverse. This time, it seemed to do the trick as the motor would freely shift into forward, neutral and reverse. After I got done setting of the muffs, I came back and tested it again, and now it would no longer shift into reverse. At this point, I disassembled and ensured the shift rod was in its minimal position and the gear was reverse and reassembled. The same thing happened again. I decided to run the motor on muffs anyway and see what happened. On muffs, the motor ran fine in forward and reverse, maybe a little rough into reverse but reverse has always felt a little rough. Tattle tale flow was much stronger and more in the lukewarm range after the water pump change. Now I am wondering if I ever could shift into reverse with the engine not running. Is this something to be concerned with?

 

[99yam40]

if the motor is not running or drive shaft or prop shaft not turning, there is a good possibility that the clutch dogs will not line up properly.
if you try to force it you can bend things