Revised question for Dhadley Thermo-switch

[John Bett]

Dear Dhadley, Thanks for the information about the Thermo Switch on my '72 125 Evinrude which I would have never have found elsewhere! I have bypassed it, but I still have the same problem which I didn't fully explain before. What is happening is that when the ignition is on, and engine not cranking, and when I activate the electric choke switch, it fully pulls the choke butterflies closed which is great, but when cranking, and, with the engine running, when I activate the electric choke switch, the butterflies only close about 70% which is the same as when the Thermo-Switch was hooked up. This is a problem since I am not getting full choke at startup. Since it has a full pull on the butterflies when the motor is not running, I assume that the choke soloniod is ajusted correctly in the clamp. Is this problem something that you have seen before?<br />Thanks, John

 

[Dhadley]

Re: Revised question for Dhadley Thermo-switch

Did you try moving the solenoid further down?

 

[John Bett]

Re: Revised question for Dhadley Thermo-switch

Thank you for your reply. Yes, I did move it down, all the way, but it is as I said before. When the engine is not cranking or running, it has a very strong "full pull" and absolutey closes the choke butterflies which is what it needs to cold-start, but when it cranks, (or is running) it only pulls about 70%. Makes me want to try to wire the choke system completly independantly of the motor harness. funny thing?<br />Thanks, J.

 

[John Bett]

Re: Revised question for Dhadley Thermo-switch

I was thinking.... Im not much of an electritian, but what if I check the voltage to the choke solonoid when it is working right (with the ignition switch in on, not cranking) and compare it to when the engine is cranking or runniung, and if it differs, then try to determine where the drop is?

 

[walleyehed]

Re: Revised question for Dhadley Thermo-switch

The drop is the starter spinning...you may have a (Shortly) bad starter, or a possible loose ground.

 

[Walker]

Re: Revised question for Dhadley Thermo-switch

Makes me want to try to wire the choke system completly independantly of the motor harness.

Disconnect the wire to the choke solenoid and run a jumper wire from the positive battery post to the choke solenoid, then crank the engine. That will isolate the engine wiring.

 

[Dhadley]

Re: Revised question for Dhadley Thermo-switch

There was an old bulletin about that problem. If I remember correctly they wanted you to wire in a diode. I'll have to think about this a while to remember where. I do remember it was real simple. Hummmm.....remove the red wire under the main positive cable on the solenoid and wire it in between the small red wire and the solenoid post???<br /><br />Anybody have that old bulletin?<br /><br />Basically it stopped the starter from pulling all the juice away from the red wire.

 

[John Bett]

Re: Revised question for Dhadley Thermo-switch

Dear Dhadley,<br />I was able to fix my choke problem by ajustment of the choke solonoid. I had to modify the bracket to allow for a longer pull of the rod to compensate for the voltage loss durring startup. But this discussion and your knowlege has really informed me about things I would have never otherwise learned.<br />I tried to search for the bulletins you spoke of, but they dont seem to be available. I'd love to have all applicable, but when you have a 33 year old engine, its tough.<br />Thanks for your help!!!

 

[seahorse5]

Re: Revised question for Dhadley Thermo-switch

Dhadley,<br /><br />I believe that that the diode starter by-pass bulletin was for the '67 and '68 100hp motors and the '69 and '70 115's. I remember modifying a lot of those engines many years ago so the power packs would get enough voltage during cranking.

 

[Dhadley]

Re: Revised question for Dhadley Thermo-switch

Ah! That may have been it. I told you we were over-taxing an already old memory bank.