new thermostat

[South of Heaven]

I forgot to ask you guys about this last week...I replaced the thermostat on my 2003 Yamy F80. The one that we pulled out was rated to 50 C but the one that we installed was a 60 C. I bought it from the local Yamy dealer and it was specific to my year, make and model as per the dealer.

Should I be worried that the thermostat will now start functioning at 10 degrees C hotter (140 F as opposed to 122 F) ?

[Sunbeam]

I don't know if this would make any difference to you (in terms of sourcing parts) but I thought the Yamaha F80/F100 was only made through 2002. Then in 2003 it became the F75/F90 (I'd guess it was something about horsepower measurement rules rather than change in the engine), and then I believe in 2005 the engine was changed to fuel injection (which of course was a real change).

So if you have an F80 it seems as though it may be a 2002 (?). Now maybe the thermostat for a 2003 F75 and a 2002 F80 would be the same anyway, but I just thought that in case your engine is a 2002 F80 you might like to know that for purposes of discussion, parts ordering, etc.

A quick way to tell is to look at the last character of the model number. If it's an "A" then it is a 2002. A 2003 would have a "B" as the last digit. So my 2002 F80 is model TLRA, which means power trim tilt/long shaft/remote control/2002.

Here is a "decoder" for Yamaha which covers the years 1991-2005. Sorry about the poor image quality.



While we're on the topic, you might be interested to know when your boat was made. Maybe it's an early 2003, which would easily explain a 2002 engine. If you look at the boat's HIN (on the transom, starboard side near top), the last four digits will tell you two things: The first two of the set will tell you the month and year the hull was laid. The letter is the month (A=January, B=February, etc.) and the number is the year. Then the last two are the model year of the boat. So for example if your HIN ended in J203 then your boat's hull would have been laid in October of 2002 and would be a 2003 model year. Oftentimes the years match, but it's not uncommon to have a split like in the example for a boat started late in one year but completed in the subsequent year.

[South of Heaven]

My model number/letters are : F80TLRB

Here's a link to the NADA values for Yamy's in 2003. There was a 80 in that year.

http://www.nadaguides.com/Boats/2003/Yamaha/Outboard-Motors

[Sunbeam]

Very interesting! (Well, at least to detail-obsessed nerds )

Most of the websites I've looked at say the F80 went up to 2002 and then became the F75 in 2003. And Chris of Rana Verde has an F-75 and he bought his 2003 C-Dory 22 brand new. Oh well, not that it's a big deal now, just interesting.

[BrentB]

I checked SIM Yamaha and the thermostat is Part # 67F-12411-01-00 and Boats.net shows the part #, item and temperature printed as 60C
see
http://www.boats.net/parts/detail/yamaha/Y-67F-12411-01-00.html

The computer or ECM uses the temperature sensor to control the air-to-fuel mixture. If the engine is cold, the ECM opens the injectors longer to provide more fuel. As the engine heats up, it needs less fuel for the mixture and the ECM decreases the injector on-time.

I guesstimate only minor issue not a major one.
You would need a live feed from ECM to determine the effect.
Maybe Yamaha Diagnostic Software would graph it.
or
I am a lazy man and buy the Yamaha thermostat for the model

LOL and m2cw

[Sunbeam]

So it sounds like the 50ºC one that was already in there was the "wrong" one and the 60ºC replacement is the standard/recommended one.

I just placed an order from SIM a few minutes ago for some F80 goodies. Good place for Yamaha parts and information!

[BrentB]

I used 2003 Yam F80 at SIM, went to this page
2005 & OLDER 4-STROKE | 2003 | F80TJRB,F80TLRB
Thermostat
Part # 67F-12411-01-00

Superseded from Part # 67F-12411-00-00
see
https://www.simyamaha.com/category_s/1455.htm

then found the pic showing the temperature, url in previous post

Both stores are great. I buy from SIM due to Andy's excellent service and didnt shop around at Boats

[Dora~Jean]

Just as another data point, I also have Yamaha F80's (2), Model F80TLRB. The manufacture date imprinted on the motor is 7/2002. So I guess like boats manufactured in July, they are considered the next year.

[BrentB]

PRESSURE CONTROL VALVE KIT FOR FOUR STROKE MODELS F80-F150
located at
http://www.boats.net/parts/detail/yamaha/Y-67F-12411-01-00.html

might need an inspection

The valve is closed at low speeds so that the thermostats keep the cylinder head and block temperature close to 140 degrees for better combustion and resistance to fouling plugs and carbon buildup. At high speeds, when internal combustion temps are high, the valve opens and water flows thru the block at a higher rate and the motor water temp stays cooler.

[Sunbeam]

Dora~Jean: More data points - always good! Especially since the C-Dory/F80 club is fairly small

Maybe the deal is that they only *made* them through 2002, but then as you noted, some of those made in the last half of 2002 are model year 2003. Kind of like how you can't buy long underwear in January because that's when they sell swimsuits

As long as you popped in, I'd like to thank you for all the good F80 information in your album. It's been very helpful (South of Heaven, you might enjoy checking it out since you have an F80).

[South of Heaven]

Thanks guys. Yeah, us F80 owners are definitely in the minority here. Lol