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sdm1976
06-15-2007, 01:46 PM
I am new to the business and have never owned any commercial equipemnt until now. This question may have been kicked around a hundred times and could be a worn out topic,but do you have to run a trimmer at full throttle to increase the life of the engine? I have heard to run it full tilt or it will foul the plug. thanks for any info

Grits
06-15-2007, 01:54 PM
They are made to run at full throttle, but running at such a high speed is silly most of the time. I tend to run mine at about half throttle in most situations. Sometimes I run at full throttle if there is a decent sized area of grass that was unable to be reached with a mower.

johndeerefan
06-15-2007, 03:46 PM
They are made to run at full throttle, but running at such a high speed is silly most of the time. I tend to run mine at about half throttle in most situations. Sometimes I run at full throttle if there is a decent sized area of grass that was unable to be reached with a mower.

yep same with me

coonman
06-15-2007, 04:15 PM
They are made to run at full throttle, but running at such a high speed is silly most of the time. I tend to run mine at about half throttle in most situations. Sometimes I run at full throttle if there is a decent sized area of grass that was unable to be reached with a mower.

Same here. My Redmax is going on its 4th season. Don't worry about it.

sweatyclippingcoveredguy
06-15-2007, 04:51 PM
Anywhere there is a possiblility to throw stones or damage something I keep it low. Otherwise, full speed ahead.

lawnmaniac883
06-15-2007, 07:32 PM
Only use enough throttle to get the job done. Saves gas and trimmer line. I run it at wot when I need to but usually half throttle does it.

lawnspecialties
06-15-2007, 08:13 PM
I also run mine at around half-throttle. Trimmer line is so far advanced in design, it cuts easily without needing tremendous speed.

One thing, though. Running two-stroke equipment half-throttle tends to cause carbon build-up in the exhaust port over time. During the off season, pull the muffler and gently scrape out the carbon in the exhaust port. This will keep your muffler from getting "stuck" to the block and keep that exhaust port clean. Believe me from experience, when that exhaust port starts to clog up from carbon, you'll be wondering what in the world is killing all my power? :hammerhead:

Richard Martin
06-15-2007, 08:18 PM
I only use enough RPM to get the job done. If it fouls a plug I don't care. I'd rather not accidentially slip and burn the grass to the ground. That and I buy spark plugs on eBay. 25 CJ-8 plugs for $20 shipped. I'm still working through the bag of plugs I bought 3 years ago. I think there's somewhere around 20 plugs still in the bag.

sheshovel
06-15-2007, 08:22 PM
Balls to the walls.

Ocalalawns
06-15-2007, 09:17 PM
The echo rep told me that it needs to be run full throttle since this is what cools the engine. I run full throttle most of the time and my trimmer is 8 years old without any problems.

Digdug
06-15-2007, 09:34 PM
The echo rep told me that it needs to be run full throttle since this is what cools the engine. I run full throttle most of the time and my trimmer is 8 years old without any problems.

Yes maybe your flywheel is blowing air over the cylinder fins to help cool the engine. But your oil / gas mixture is doing more to cool your engine and prolong your engine life. Your engine definetly will last longer with less RPM's . #1 because it is turning over less , and #2 it is getting twice the oil needed to lubricate the engine when you are running at 4000rpms versus 8000rpms. doug

lawnspecialties
06-15-2007, 10:09 PM
Balls to the walls.

Ironic response there.;)

Bama Mower
06-16-2007, 01:18 AM
Ill have to go with what sheshovel said and say balls to the wall.

jsf343
06-16-2007, 02:02 AM
Only use enough throttle to get the job done. Saves gas and trimmer line. I run it at wot when I need to but usually half throttle does it.

I agree with this and many of the other posts. Only run as much as needed most of the time especially around dangerous areas, cars, people, windows, etc.

Richard Martin
06-16-2007, 05:15 AM
#2 it is getting twice the oil needed to lubricate the engine when you are running at 4000rpms versus 8000rpms. doug

Would you care to explain the theory behind that?

The oil is in the gas. The engine is going to use X amount of fuel for every revolution regardless of how many times it rotates in a given time frame (read that as RPM).

The engine only uses roughly twice as much gas at 8,000 RPM as it does at 4,000 RPM simply because it's turning twice as fast. Since it's using twice as much gas it's also getting twice as much oil, not half.

Digdug
06-16-2007, 05:17 PM
Richard, the oil mix is set for wide open throttle . Lets say 40:1 ratio. So any variation of less throttle means the engine is getting more oil than needed. You are correct in saying the engine is getting less oil and gas , that is correct . But the ratio is still 40:1 and needs only be 80:1 at a less RPM because there is less heat and friction. An example to prove this theory is to let your weed wacker sit idling for 15mins. and you will see it is running rich on oil and will smoke or possibly foul a plug.
This is where oil injection takes over in outboard engines, dirt bikes, snowmobiles, etc. At wide open throttle the oil injector is giving the engine 40:1 and at a idle as little as 100:1 .
So this is why i was telling the gentleman his rep. gave him bad advice saying the wacker engine runs cooler or will last longer running it wide open. doug

Richard Martin
06-16-2007, 08:41 PM
So you're saying that since I am already running a 80:1 mix (Amsoil) that I could run it at 160:1 since most of the time I spend at half throttle?

Granted these engines do make more heat at higher RPM but the oil requirements are still the same. Your oil injection injects more oil at higher RPM simply because the engine is turning faster, not because it needs more oil per RPM at higher speeds.

Imow4u2
06-17-2007, 09:51 AM
Yeah half gas most of the time, I still open it up to "clean it out" at least 2-3 times a day

Prestige-Lawncare
06-17-2007, 10:01 AM
Balls to the walls.

Ironic response there.;)

I was kinda thinking the same thing :laugh:

SEALAWNMANAGEMENT
06-17-2007, 01:07 PM
I run mine at about half speed. Unless you are trimming something tall it just a waste of fuel. I have a stihl that I just changed the plug in this year. Its 5 years old. Mechanic said it was the cleanest plug for that age he had ever seen. It has been used a lot.

Digdug
06-17-2007, 04:18 PM
So you're saying that since I am already running a 80:1 mix (Amsoil) that I could run it at 160:1 since most of the time I spend at half throttle?

Granted these engines do make more heat at higher RPM but the oil requirements are still the same. Your oil injection injects more oil at higher RPM simply because the engine is turning faster, not because it needs more oil per RPM at higher speeds.

Yes, you could run your mix at 160:1 probably at a idle. N0 the oil requirements are not the same at a idle versus wide open. Wide open the oil injection pump is probably pumping in a 40:1?? ratio. At a less RPM it is pumping in less oil. The oil requirements are not the same as you are stating.

Oldtimer
06-17-2007, 05:33 PM
The downside of running part throttle is building carbon deposits in the combustion chamber. The deposits can break off and score the cylinder and piston just like it was operated with inadequate air filtration.

The flywheel forces air around the engine to aid in cooling and the higher the rpms the more cooling air. The carbs run very lean so don't run any extra oil because only so much fuel/oil mix will go thru the jets.


Oldtimer

Damian
06-17-2007, 07:39 PM
I look at it like this: these things have a variable speed trigger for a reason. Around trees, fences, etc., I go much less than full speed. I definately go less than full speed when tapping it for line.

Oldtimer
06-17-2007, 07:53 PM
I look at it like this: these things have a variable speed trigger for a reason. Around trees, fences, etc., I go much less than full speed. I definately go less than full speed when tapping it for line.

Remember, the clutch won't fully engage until about 2/3 of max engine speed.


Oldtimer

You can lead them to water but you can't make them drink!

causalitist
06-18-2007, 02:06 AM
that would just be straight up annoying to run wide open.

i run just a hair above idle, and my clutch hooks up just fine.

carbon deposits from low rpm? , i might just lean out the low speed screw then.

i dont care anyway, these things run for 4-5 years, if i get one less because im not redlining the tiny engine for hours on end so be it ... but i doubt thats the case.

i think i'll start opening it up all the way for 60 seconds at the end of each day, wouldnt doubt that would take care of any carbon.

causalitist
06-18-2007, 02:10 AM
I run mine at about half speed. Unless you are trimming something tall it just a waste of fuel. I have a stihl that I just changed the plug in this year. Its 5 years old. Mechanic said it was the cleanest plug for that age he had ever seen. It has been used a lot.

im curious what oil you use then.

fergman
06-18-2007, 10:10 PM
i know a guy that has at least 8 t-230 shindaiwas and they are run 6 days a week daylight to dark at 1/4 to 1/2 throttle and are still running. they are all at least 6-9 years old. But none of his workers ever run full throttle so they finally wont hardly run at all then they take them 2 have the carbon in the exhaust ports cleaned out :confused:

JoeKidd
06-18-2007, 11:20 PM
I work at a private cemetery and trim for two to three straight hours in the morning five days a week. I'm on my seventh year with my Echo SRM-260 and run it about 1/2 throttle most of the time and I've had zero problems with it.

Mark in MD
06-19-2007, 09:40 AM
Only use enough throttle to get the job done. Saves gas and trimmer line. I run it at wot when I need to but usually half throttle does it.Yep. Me too.