Not sure where to mount Faria Temp Sender on my '91 90-HP Johnson

[rkhanso]

I bought a Faria Temperature Gauge and wanted to install it on my '91 90-HP Johnson 2-stroke. The instructions say to remove a head bolt and make sure the surface if tight/flat against the cylinder head.

It appears there's some other cover (water jacket?) on the outside of the cylinder head. There aren't any really good flat areas on that cover. There are some ribs and low spots. There appears to be a ridge under every gray painted bolt that is higher than the cover surrounding it, so the sender won't likely mount flat against a metal surface and actually have a 1/16" or so gap under the sender.

I could drill another hole in the mounting bracket of the sender closer to the actual sender part and mount it on the top of the starboard cylinder, pointing at 3:00-4:00 direction. But the bracket is not much wider than the raised area on the cover under the bolt. I suppose I could use an extra washer maybe?

I suppose I could also put some of the white CPU/Heat paste inbetween the sender and head.

Has anyone been able to find a good place to mount this surface-type temperature sender?

Here are some pictures of the mounting area
Port:


Starboard:


Side View:


Sender:

 

[F_R]

Don't use the water cover, they will give a false reading. Strive for as high up as you can get, preferably on the exhaust side. Use a washer if you have to.

 

[rkhanso]

Don't use the water cover, they will give a false reading. Strive for as high up as you can get, preferably on the exhaust side. Use a washer if you have to.

Thanks for the reply. I really don't see anywhere higher or another location to mount it. There's not much surface area near the head bolts.
Is it acceptable to mount it on the side of the cylinder instead of the head?

The instructions say to use a head bolt for mounting, but the picture really seems to show the water cover.

In Figure 1, it looks to me like it's showing the water cover.

 

[F_R]

Wherever you put it, it will display the temp at that location. That's why I try to put them at the hottest location. But in all reality and practicality, if you put it somewhere else and get a feel for what's "normal" for that location, you will still be able to detect what is not "normal". Heck, put it at a convenient spot and give it a try. You can always re-locate it.