# Altering engine speed



## C20 (Jan 4, 2009)

Hi folks....LTL FTP (Long Time Lurker First Time Poster)

I have a generator with a Suburu EX30 engine and it has only one engine speed setting.....full blast. What I have been doing is using a zip tie to hold the throttle back to a slower speed by tying back the carb linkage attached to the engine itself. I think the linkage has something to do with weights in the engine that help it not bog down. I do this because I hate the idea of a cold engine starting at full throttle. Also, there isn't always a need for full power sometimes because often I am only running a few lights. My question is tying back the throttle harm the engine is any way?

Thanks
Dave


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## bgbass (Jan 11, 2008)

You should let it run the way it was meant the manufacture set the motor to run at a certain rpm so it will run at its best. By cutting back on the rpm you could do more harm than good.


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## C20 (Jan 4, 2009)

I guess I was thinking that most small engines are made to fit many different applications and those applications many require different throttle speeds. I know that some generators have throttle control but I don't know if the "speed weights" in those engine are left off. Does that reasoning make sense?

Thanks again


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## Maytag (Dec 10, 2007)

*let me shed a little light.............*

Hey - I'm not a generator guy or nothin', but if I remember right the generator is governed (speed weights) so that it runs at a PRE-DEFIND speed. Thus the definition of governed. In order for the generator to give you proper power it must run at an EXACT speed. This engine speed equates to cycles per second (frequency) at the generator outlets. Most generators in the Western Hemisphere are set to "generate" voltages with a 60 hertz (60 cycles per second) sine wave.
If you tweek your governor to make the engine run slower you get less hertz and thus your appliance (light bulb) turns on and off (sine wave) less times per second and thus gives off less light. Fine - hunky dorey - okey dokey for a light bulb, but plug in an appliance that needs 60 hertz and only gets 50---your just asking for a repair bill.

my 2 cents -minus inflation, carry the recession, dot the "I", prime the pump...
>disclaimer - I'm not an engine or generator expert, but I know I'm not far from correct. Hope this helps.:wave:


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## dj722000 (Oct 29, 2008)

The weights cant be left off. Wouldnt run correctly. Havent you noticed when using a generator and its running with nothing plugged in it goes down to a idel speed that is preset. This is done by a idle control circuit. (Little switch that says idle control) When you pull power from it, i.e., lights, drills, saws anything the engine revs up to a preset speed. Turn the idle control off and it runs at max rpm for the generator. Then your just wasting gas and wear and tear. This is on some better generators. Dont know about the cheap ones. However, I would use a light weight oil in it for cold weather starts. No matter If engine is running or not, there is still a thin film of oil on all moving parts. It will never dry start unless you take it apart and clean it all out and put it back together. Not recommended. When its cold, the oil is thick and heavy, slow to splash up on moving parts, this is why you need to come down to a lighter weight oil in cold weather. Your manual should tell you what you need to know. Besides, the manufacturer made it this way for a reason. I wouldnt mess with it except changing to a light weight oil.


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## C20 (Jan 4, 2009)

You make a good point about maintaining the proper hertz level. As I mentioned in my original post, my generator doesn't have any external throttle speed control. It's either full bore or nothing. It's pretty much a bare bones unit. My biggest concern is starting the engine cold and at full throttle. It's contrary to everything I have ever learned about engines. I have switched it to Mobil 1 5W30 oil but it still bugs me and that's originally why I decided to tie back the throttle. To let the engine warm up before letting it rip. Are my concerns unfounded?


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## paulr44 (Oct 14, 2008)

C20 said:


> You make a good point about maintaining the proper hertz level. As I mentioned in my original post, my generator doesn't have any external throttle speed control. It's either full bore or nothing. It's pretty much a bare bones unit. My biggest concern is starting the engine cold and at full throttle. It's contrary to everything I have ever learned about engines. I have switched it to Mobil 1 5W30 oil but it still bugs me and that's originally why I decided to tie back the throttle. To let the engine warm up before letting it rip. Are my concerns unfounded?


While we're all taught most engine wear occurs during cranking, and that "flooring" it right away isn't good for it (true), there's defacto and dejure. Defacto being what is in the books, and what we're taught. Dejure being what's practiced daily. All typical generators, even those will idle controls will surge to full throttle immediately, and those with idle control will then idle down until elec. power is drawn which causes it to rev. back up.
On the other hand, that engine is probably rated for about 500 to 700 hrs. of use, and that's far more than most homeowners would use a generator for before parts are NLA. I see it all the time - high end products in homeowner hands, even with mediocre maintenance they outlive parts availability.
So, don't fret - if it works okay and you only use it occasionally, let it ride. If you use it a lot, and you'll sleep better rig up a manual link to hold it at a lower RPM whilst it warms up *until* you're ready to use it.


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## C20 (Jan 4, 2009)

Ok, bottom line, not a good idea to run generator slow when powering things but for warming up the engine it should not damage anything on the generator itself. Sound right?

I appreciate your input


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## dj722000 (Oct 29, 2008)

Correct.


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## paulr44 (Oct 14, 2008)

dj722000 said:


> Correct.


Chess


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## dj722000 (Oct 29, 2008)

Ohhh I like chess. Specially 3d. LOL


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## paulr44 (Oct 14, 2008)

Rook to king's knight 8: check, mate. LOL I played table 4 back-up, state champs varsity. Many, many years ago. Last century, I think.


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## dj722000 (Oct 29, 2008)

Thats pretty cool. Most kids dont like it, to much BRAIN work. I just play with friends and such. Never got into it that much, to many other things to do. Back in ot2 was last time I played. Oh, thats 2002 in my years. LOL.


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