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 wrote:
blumonster -  Normally on a set up such as this.  You would increase the tension of the gov. spring to increase the RPM.  All of the old Toro 2 cycle blowers had set ups like this  The gov spring was either attached to a metal tab that you would bend to increase the spring tension.  Or it was connected to a small bracket that you would loosen and slid to increase the spring tension.  The set up on the Honda HS35 is the same way.  You move the spring to another hole in the bracket which is further away from the gov. arm which increases the spring tension, which will increase the RPM.  Having said that, if the gov spring is very old there is a good chance that it has lost some of it's spring tension.  So moving it to another hole may or may not do what it should do.  In that case a person can buy a new spring or shorten the loop on one end of the old spring.  Shortening the spring a little will increase the tension to offset what has been lost over the years.
As I posted before.  Loosening the gov. arm on the gov. shaft should really not ever have to be done unless the bolt has some how come loose.  Doing that procedure simple resets the gov. to it's original setting.  It won't help or change anything
if you have a bad gov spring.  The gov works against the gov spring.  To weak a gov spring lower RPM  to strong a gov. spring and you will over rev the engine.

On my Tecumseh two cycle engines, I've tied a piece of string to the governor lever arm and run it outside the plastic housing up the handle and rigged it to work like a throttle.  I let the machines idle down when not under load then put tension on the string to pull the arm to over-ride the governor.  I get some pretty good engine speed and power doing this.   The engine is rated at 5 h.p. at 3600 rpm, which I find a bit of a stretch.  However, crank it up to 6000 or 6500 and it makes some serious power.  Enough to impress me with how much and far it pump snow.   I use the old SS machines like a I use a chain saw.  No load, no rpm.  Heavy load, high rpm.  It's actually quite controllable.

borat wrote:
Wow, 6500 RPM?? The engines hold up OK at that speed? Granted, you're only doing that occasionally. The extra RPM would give you a great boost in impeller/paddle tip speed, which must be a big help. At least with a 2-stroke you shouldn't have to worry about valve float and things like that.

The owner's manual on my ex HS35 states 3.5HP at 1800RPM.  The HS35 I had was the very first model prior to the updated CDI HS35, which was used on serial number greater than 104XXX.  If my owner's manual is correct with1800 RPM then 2200 RPM is not too far out and within the range.  Perhaps this explains why the engine would sound really bad at higher RPM as it is not designed to rev that high.  I could see my piston flying out at 6500RPM, which would have been a nice show.

borat wrote:
I may try that.  I have a Toro CR20E and a CCR2000 that I've rehabbed.  I usually just tighten up the gov spring and leave it.  But I like the idea of being able to slow them back down.
A neighbor and I where helping out a friend with their snow last year.  And my friend said boy your blower sure throws snow better than mine.  He had a CCR2000 and at the time I just had a CCR1000.
I just kind of smiled, and told him I could fix his if he wanted. 

jrtrebor wrote:

Thank you jrtrebor.

MN_Runner wrote:

MN_Runner, the shop manual I have is published in 1980 and printed in 1986.The updates are covered in the supplement to the manual.

4000RPM is mentioned in the main part of the shop manual.It is interesting to have two different governed RPM values.

My machine too is the older version with frame serial number smaller than 1048...If we believe the owners' manual then everything is OK. (?)

MN_Runner, I just looked at the owners' manual I had downloaded before.There it says 3.5hp@3600RPM.But it is for C.D.I.

Where did you download yours from?

The previous owner (college professor) gave me his original manual in an impeccable shape.  I passed it to the new owner.  It was just confusing , your service manual says 4000rpm and at that RPM my HS35 engine sounded like it was going to throw up the piston.

@MN_Runner,

No more single stage snowblowers?  Maybe a Toro 621?