Tecumseh 10hp Throttle issues.

[ThatGuyYouKnow]

Im back! Ok this issue is driving me crazy. I have two generators with Tecumseh HM100 motors. Recently put new carbs. Both run but one runs fast but not running away just too fast. The thing Ive noticed is while both are running the throttle never touches the screw on the carb for idle speed. Even with the screw all the way in it wont touch. Now how do I adjust the idle speed?? The manual only shows a picture but not how to adjust it. I know that on any other small engine you use the idle screw but these two the screw does nothing.

 

[Hammermechanicman]

You say these are on generators. Do these generators have an eco idle mode? If not the idle screw at the throttle butterfly is not doing anything as the engine should be running arou d 3600 all the time. The speed is controlled by the govenor.

 

[Rivets]

I second what Hammer said, you probably have a fixed throttle unit, runs at only one speed. If you check the ACV and Hertz you should see approximately either 110 or 120 ACV and 50 or 60 Hertz, depending on what you ID plate says. Can’t remember if I’ve ever seen a Tecumseh engine with an Ecno-throttle.

 

[ThatGuyYouKnow]

No eco idle mode. I believe these are fixed speed engines. One of them runs fine but the other runs a decnt bit faster. I dont have a tact meter to check rpms. I dont know which way to adjust the nut on the governor link. I kinda figured thats how it was suppose to be but just wanted to make sure. The manual mentions nothing about ones with this setup.

 

[Rivets]

On a generator RPMs are not as important as output ACV and Hertz. Not having these correct can easily result in burning up equipment.

 

[ThatGuyYouKnow]

That I understand but I have no current way to check for hertz. I do know compared to the same engine on the other generator that runs fine this one is running too fast. I know that if its running to fast it will burn up the generator.

 

[Rivets]

Remember I said RPMs are not as important as voltage and hertz. It may be that the one unit is running at a higher speed to achieve the proper voltage and hertz. I’ve seen units which may have too run at 3800 RPMs to get proper voltage . If you have an Advanced Auto or Auto Zone parts store in your area, they lend out tools for free, so you might try them to see if they have a meter you can borrow.

 

[StarTech]

If you have a tach then it easy to figure out as long you if you got two pole or four pole alternator. Most gasoline powered units will be two pole. Most Diesel powered units are four pole.

Two pole RPM to Hz calculation is RPM / 60 = Hz Example 3600 rpm = 60 Hz
Four pole RPM to Hz calculation is RPM / 30 = Hz Example 1800 rpm = 60 Hz

You want off load RPM to be 3750 rpm for gasoline powered 2 pole alternator. This allows for a 150 rpm governor droop under load.

Just note that if you are in an area that require 50 Hz the RPM changes so convert 50 Hz * 60 = 3000 Rpm or 50Hz * 30 = 1500 rpm.

 

[ThatGuyYouKnow]

Ok I understand you know Rivets that may be case. Today I measured the length the bolt for the speed protrudes and they are the same length. One does seem to have a stronger spring but that may just be me.