Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

I just started using my new hour meter/tachometer today on my blower, and it peaked out at only 3180rpm, but steadily displayed 3120rpm.  It is this one:

http://www.amazon.com/Tachometer-Kawasaki-Motorcycle-Generator-Snowmobile/dp/B0049IFX56/ref=sr_1_cc_1?s=electronics&ie=UTF8&qid=1321768364&sr=1-1-catcorr 
         

Using that horsepower-to-torque formula (HP = torque x rpm, divided by 5252), I get 8.66 HP at 3120rpm.  At 3600, it would be 9.993 HP.  For the formula I used a torque figure of 14.58, which I got by plugging in the assumed Tecumseh 10.0 HP figure at the assumed rpm of 3600, into the torque-to-horsepower formula (HP x 5252, divided by 3600).  Lots of assumptions, I know, but I had to get the torque figure that way so I could turn around the formula to get my horsepower figure at 3120rpm.

Anyway, I don't know if this meter is accurate.  When my son and I get his Ariens ST824 put back together again (took it apart to paint the inside of the housing; adjust the chains; replace the friction disc, cracked handlebars, and beat-up/bent impeller; serrate the augers using a Platinum 30 cardboard template I made while at Home Depot; greasing the chains, auger shaft, and friction disc shaft), then I will try my tachometer on his machine.  I may just pick up another meter to compare in the end. 

If the reading is the same on his, or close, then maybe it is the meter.  If he gets around 3600rpm at full throttle, then maybe I need to adjust my governor.   If I do have to adjust it, does anyone know how to do that?  It's only a three-year old Tecumseh L-Head 358cc.  Thanks for any help.

blumonster,

Can you post a picture (from the service manual) on how the choke rod is connected to the carburator?  There is a small spring on top the carburator and trying to figure out how that spring is attached or used in conjunction with the choke rod.  Thanks,

MN_Runner wrote:

I hope these pages are the related pages:

RPM increases if I manually move the governor but does not seem to stay at a higher RPM if I just make the spring tighter.  No matter what I do, the RPM ready 2300.  I think this is too low of RPM to effectively blow/move the snow.

trouts2 wrote:
Thanks, trouts2, I will take a look at that manual. 



Shryp wrote:
Shryp, I watched donyboy's video.  It was very good.



borat wrote:
Borat, I think that's probably the case.  I read somewhere recently that 3060rpm is a common, though not a standardized rpm to figure torque.  That can easily vary from one engine model to another.


Thanks, guys.  I think my new meter is probably okay.

MN_Runner, you'll probalby have to go through the adjustment for the arm and shaft.  If doing that and trying another spring position does not work then you could try modifying the arm position on the shaft to make the car butterfly more open.  

MN_Runner wrote:
How old is the machine?  It very well could be the spring needs replacement as it has lost its mojo.  Heck it connects directly to the exhaust.  The heat cycling and age could have sapped the tension right out of the thing.

I just ordered the governor spring from my Honda dealer so I will give it a try on Wed.  I moved some snow from the grass to my driveway and tried the blower.  It does blow snow better than I expected.

MN_Runner wrote:

I am looking forward to hearing how it effects the RPM.If it works I will get one too.

blumonster,

I would get this one from Northern Tools: http://www.northerntool.com/shop/tools/product_524744_524744?cm_mmc=Google-pla-_-Engines-_-Small%20Engine%20Accessories-_-160590&ci_sku=160590&ci_gpa=pla&ci_kw={keyword}

EMS brand is $39 but maybe worth the money.  I have some doubts about my current cheap tachometer (about $15-20 including shipping).  It blew the snow better and farther than I thought it would but I could hear the engine slowing down when it went over about 6 inch of snow.  I am encouraged.

I will let you know when I install the new governor spring if it gets better. 

If you have a generator, hook the untrusted tachometer to that, and see if you get 3600 RPM.

On the flip side, if you have a generator, but no tachometer, if you have a device called a Kill-A-Watt, it will show you the frequency of your wall outlet power, to 1 decimal place. It also shows the voltage of the outlet, and the amps and watts being drawn through it. During the recent snowstorm power outages in New England, I was using my Kill-A-Watt to keep an eye on how the generator was doing under increasing loads. I could see if it was slowing down (less than 60 Hz), and what the voltage was (eg- ~125V with no load, dropped to ~118 as I loaded it up).