Labyrinth seal design. known issue

[2strokesmoke]

I stumbled accross this issue searching for something else. Yes, I used the search button afterwards.
I have a 2000 9.9 stroke, 15hp after reed change. It runs fine, I have no issues with the motor. Low hours, like new. Good compression, 115 on both.

I dont know anything more than what Ive read about this motor but it seems the labyrinth seal is made of rubber and is a known issue that was changed in 2004.
Should I be considering selling this thing before I can get nothing for it but scraping out parts? I went from a 76' rude to this and was hoping this thing would last me for years to come.

[rodbolt17]

never had a problem with one.

[2strokesmoke]

rodbolt17, are you saying you have had similar motors and have not had an issue?

Upon further investigation, looking at parts lists, I see that between 1997 and 1998 they went from offering all the parts that make up the crankshaft including the labyrinth seal to only offering the fully assembled crankshaft. So after 98 you can no longer purchase the seal (among other parts on the crank) individually.

Another post mentioned Yamaha changed the labyrinth seal from rubber to aluminum in 2004, I cannot find anything to support that though.

Assuming i have the motor with the rubber labyrinth seal that is more likely to fail than others, can anyone suggest anything to prolong its life?

-Run 50 to 1 instead of 100 to 1? I do this now, mainly cause I dont run but every few weeks at most.
-Decarb with a fogging oil more frequently?
-Remove the 15hp reed vavle and stick to the lower RPM of the 9.9?

Also, I accept I may be over analysing this. Seeing as how I cant find much info on it tells me not many have had an issue. Might not be the best design but doesnt fail a whole lot?

Thanks for any responses.

[arny]

My bad,the changes was made in 2000 not 2004. Found on the internet
ftp://os2.fannet.ru/Boating/Yamaha/T...O/OE-00010.pdf

[2strokesmoke]

My bad,the changes was made in 2000 not 2004. Found on the internet
ftp://os2.fannet.ru/Boating/Yamaha/T...O/OE-00010.pdf

arny, i put http at the beginning of your link, I cant seem to go to an enlarged page but see a smaller version. I owe you lunch or a beer or something!!! Thank you!

It says starting in February 2000 production, ill have to look at the other external and easier to see/find features that were changed on my motor to make sure Im all good.

Thanks again!

[99yam40]

Rodbol17 is a Yamaha Master tech and has worked on these things for some years.
I would stop worrying and just run / enjoy

[2strokesmoke]

Rodbol17 is a Yamaha Master tech and has worked on these things for some years.
I would stop worrying and just run / enjoy

I wasnt aware he was a Yamaha Master Tech. good info.

For what its worth, the link provided covers 4 stroke 9.9's. I believe, comparing parts lists, these changes were made to the 2 strokes in 98. Just in case someone has the same questions I did.

Thanks all