1908 ??? Thor motor and carb

[c.o.]

Ross, I've been wondering the same thing. Surely the right fella will read this thread and provide the answer!!!!

[Ross]

Cory I'm not sure if you noticed the serial number on the carburetor 86405 matches the engine number 8.6405. No dot. So I guess matching numbers on an early Thor include at least the engine and the carb.

[talbot-2]

Cory I'm not sure if you noticed the serial number on the carburetor 86405 matches the engine number 8.6405. No dot. So I guess matching numbers on an early Thor include at least the engine and the carb.

Interesting...I've not ever noticed a serial number on my Minneapolis "Thor" carburetor. I will check mine over the weekend.

The plot thickens.........

[Ross]

Does anybody else with a Thor have an engine serial number and a carb number match?

[c.o.]

Ross... I would have thought somebody would have provided you an answer by now. I'm still on the hunt for the answer and botherin' folks who might know!

[talbot-2]

Does anybody else with a Thor have an engine serial number and a carb number match?

Well, I checked the Thor carb on my 1910 Minneapolis Thor engine over the weekend and found that it has a serial number matching the engine number. Wow! I've had this cycle for forty-five (45) years (since 1967) and never noticed the dot in the engine serial number and now the matching carb number. I wonder if that same serial number is hidden elsewhere on the cycle. I'll have to get a little "up close and personal" to find out. Thanks to Ross for sharing his information with others.

[c.o.]

That is a good tidbit of info to remember. Come on folks..... somebody reading this must know a thing or two about putting a date on a Thor engine!!!!

[Ross]

That's cool Talbot. 35 years...wow...funny how it goes. Now if we can just figure out what year mine is??

[talbot-2]

That's cool Talbot. 35 years...wow...funny how it goes. Now if we can just figure out what year mine is??

The 1909 Minneapolis motorcycle catalog shows all of the 1909 models with Thor engines with the same identical cylinder head that your engine has. The 1910 Minneapolis motorcycle models all have Thor engines with the same cylinder head as pictured in my photo earlier in this thread. In 1908 through 1910 their two speed planetary transmission was separate from the engine. The 1911 Minneapolis used the "Unit Power Plant" that incorporated their two speed transmission in the engine crankcase. The maker of the 1911 engine is unidentified but appears very much like a Thor engine. The cylinder heads are similar to their 1910 cylinder heads.

The 1908 Minneapolis, their first year of production, had an engine made by Theim. The cylinder head on the Theim also appears identical to the one on your Thor.

The 1909 Thor motorcycle catalog also shows photos of their engines which are identical to yours.

So, I believe that your engine is 1909 or earlier. Anyone have a 1908 or earlier Thor catalog?

[Ross]

Thanks Talbot. Very interesting research. I second your request for early documentation on Thors. Do think that the 8 prior to the dot on the serial number could actually be a 1908 reference?

[Tommo]

Guys,
Do you think the letter prefix may relate to the bike the motor was fitted to.
M = Minneapolis
R = Racycle
S = Sears

Just a thought. No Proof

[talbot-2]

Guys,
Do you think the letter prefix may relate to the bike the motor was fitted to.
M = Minneapolis
R = Racycle
S = Sears

Just a thought. No Proof

No, my 1910 Minneapolis has the engine and carb serial number of "S.XXX".

[Ross]

Tommo you are on to something. I have phoned some old friends....some in Europe and Talbot is right. It isn't that easy. The letter would be a perfect answer to when is a Thor a Thor. As Talbot states some makes don't match up to their letter...HOWEVER... maybe the letter is a company entry to what model/company it represents. If you ever follow letters through on the Harley scene it can cause a headache.1911 HD Letter A and so on. Why would THOR be any different especially if they were a multiple company supplier. There has got to be some HOWARD WAGNER THOR type expert out there some where???????

[c.o.]

Not to make the wondering worse but it appears as though this engine starts with an 8 and has a distinct stamped dot behind it as well. Bummer it doesn't have a year.

http://classicmoto-cycles.blogspot.ca/2011/12/thor.html

[Ross]

Interesting Cory. One would assume it's the same engine..however the carb is different and we now know that these engines had matching engine/ carb serial numbers. Too bad there was no documented year attached to that story.