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1984 Mercury 150HP Black Max.

Has anyone ever repaired a fuel pump using one of the Quicksilver repair kits?
What's involved?
Just trying to determine if it's a job I can handle myself.
...

Ok... so after some digging around and closer examination, I have discovered that my furnace has an auxiliary limit control (150 deg. Open). I didn't notice it before because I have little...

Thanks KC, I'll give that a look as well.
What would the current-sensing relay look like (size,shape,etc.)?

Mark - I came to the same conclusion after I thought about it some more.

Anyway... I tested the limit side of the fan/limit control with a voltmeter to make sure it wasn't closing when the fan...

Good idea KC... why didn't I think of that. :)

Won't get to it until tomorrow... but I'll let you know what happens.

This was occurring before the thermostat change.

The point is... the burners turn off exactly when the 'fan on' switches on, regardless of the limit set points. They turn off cleanly and abruptly,...

Well, I replaced the fan/limit control, but the problem persists.

I'm not sure what else to do.
My only other guess as to the problem would be a short in the wiring (or incorrect wiring) between...

Yeah it's weird... the limit control "appears" to be functioning properly.

I just watched it go through a few more cycles. The burners fire up, the limit control spins until it clicks the 'fan on'...

I just noticed something.

When the limit control triggers the fan to run, the burners are turning off. Thus, the air cools down quite quickly, and the short cycle ensues. I assume that the burners...

Thanks again hvac1000.

Can you clarify...
The rate plate you mentioned. Is that on the gas valve or the furnace?

I had a chance to observe the cycling of the fan limit control, and I noticed the following:

Limit set points:
1.Fan off ~90 deg.
2.Fan on ~130 deg.
3.Limit off ~175 deg.

Starting temp. in...

Thanks for your responses.

KC13 - where should I take the temperature readings to determine the rise? Also, what would cause excessive gas input?

I have an older Sears "Fifteen" horizontal gas furnace (#867767840) located in the crawl space. Recently it has been short cycling, meaning it starts a normal cycle, runs for approximately 1 minute,...