Impeller replacement on 2016 200HP SHO

[ZO6]

Replaced the impeller on my SHO for the first time at 135 hrs. All went well. By the way, the impeller still looks great and was pumping fine.

THe 6 outside nuts and bolts were very tight and appear to have some type of white adhesive where they met the skeg on the bolt itself. I assume this was to hold the nuts and bolts in place. The Allen head bolt and the bolt under the trim tab did not have this material on them. I cannot get a torgue wrench or socket on the nuts. The nuts were a Nylock type.
1.What is this white adhesive?
2.Are these Nylock nuts supposed to be "one time" use?
3.How tight should the nuts and bolts be. I rechecked them after using yesterday and running for about 1/2 hr. Nuts were still tight. Bolts turned about 1/8 of a turn.
What is the correct way to tighten the nuts and bolts?
I added lock washers but I have reservations about this because the treads barely go past the end of the nut now.

[friogatto]

Buy a service manual

https://www.simyamaha.com/VF200_4STR...17_s/14704.htm

[McQuaig]

i looked in my service manual....the bolts use Loctite #572 (white sealant). The trim tab bolt uses Loctite #271 (Red thread lock). The manual does give torque values, but I don't know how you'd get a normal torque wrench on them. My other motors I simply snugged the bolts up really tight with a socket,....but someone might have a better idea...Also, I don't see any reason to add lock washers...

[McQuaig]

Buy a service manual

https://www.simyamaha.com/VF200_4STR...17_s/14704.htm

Yes...if you plan to do any troubleshooting or repairs yourself, the YAMAHA Service Manual is invaluable...Note: I've used "aftermarket" manuals before and they are NOT always accurate.

[ZO6]

Yes...if you plan to do any troubleshooting or repairs yourself, the YAMAHA Service Manual is invaluable...Note: I've used "aftermarket" manuals before and they are NOT always accurate.

Thanks for your informative remarks regarding the adhesive and loctite. You're right the first 2 bolts Could be torqued properly but I don't know how you can torque "properly" the other 4. I also have used sockets and a ratchet and tightened really tight before.. And it was good enough. On this SHO. a box end wrench is all I can get in there and I don't seem to have enough leverage to sufficiently tighten. The Nylon on the nyloc nuts is compressed and doesn't appear as if it would continue doing its job. Which is why I asked if they were single use and why I added the lock washers.
I appreciate your help/information and advice. It's good.

Actually, I do have the Yamaha service manual for my 200 SHO purchased from Sim Yamaha. I'm in Florida on vacation and the manual is in Arkansas. This is not the first impeller I've changed in 55 yrs of working on outboards ( mostly Mercurys and Johnson/Evinrudes ) but it is the first one in this engine and things are a little different on the SHO 200. That's why I asked the questions. My local Yamaha dealer will be open tomorrow morning. I'll stop by and get some loctite 572 and 271. And 4 nylock nuts if they have them. Thanks for your help.

[Ranger519VS]

[ZO6]

Good idea. Didn't t think about these. I ll give them a try.

[Tx Champ]

Good idea. Didn't t think about these. I ll give them a try.

Just be sure and get metric for your Yammie ... Don't think those he posted will work.

[M&M Fishing]

I know they won't they slip and you will need new nuts
get the line wrench crowsfoot work excellent

[Hawglip]

Reuse the same nuts. It is not necessary to torque those. Just get them tight. Your dealer will not replace them. Nylocks nuts should not have a lock washer. The one under the trim tab can seize due to the bolt being made of a different metal than the threaded hole. Thus I never use a thread locker on that. After all that time working on boat motors you can just do what you have always done.