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.

Coasteray: “it peaked out at only 3180rpm”

Coasteray: “I don't know if this meter is accurate.”

 

  It probably is.  Toro manuals spec’s give 3200 as their engine RPM.  It seemed odd so I called the factory last year and spoke with two technical reps who confirmed that.  You can check that applies to your machine by going to the Toro site and getting the manuals for your machine.

 

Adjustment:  On the 10hp Tecumseh the governor adjustment is usually a screw in back of the throttle arm.  It’s accessed through the opening for the throttle arm.

Here is a video of the screw to adjust the speed.

http://www.youtube.com/watch?v=GDe-VH4X5EA

Skip to about 2 minutes in if you want to skip the rest.

trouts2 wrote:
It is really great to hear from you, trouts2.  Do you know how to adjust RPM on Honda HS35?  It currently reads around 2600-2700rpm?  Not sure what the RPM should be as the manual states 3.5hp at 3600rpm.  Honda HS621 manual says 4.9hp at 4000 rpm but not sure if that model runs that high? Look forward to your professional wisdom.

Sounds like Toro have set the engine rpm to be at or near it's peak torque values. 

MN Runner:

Follow the carb linkage to watch what controls the engine speed.  You should be able to deduct where the governor resides and how to adjust it.  On my Toro SS with a  B&S R-tek engine, there's a metal tab where the governor spring attaches to that  can be bent toward or away from the spring depending on whether you want to increase or decrease rpm.  Find the governor spring and lightly pull/push it to see how the engine reacts.

Those old Tecumseh two strokes I have excellent governors to play with.  I have them modified to use as throttles.  Accordingly, I can raise engine speed as load demands rather than keeping at a rather anemic  constant 3600 rpm. 

MN_Runner,

Here is the illustration of the area:

MN_Runner,

   I'm not familiar with the HS35.  I was going to post the governer picture but blumonster came up with it.   I don't see anything there for adjustment, no screw to turn.

blumonster,

   Can you post what's on page 14, the governor adjust procedure?

   My guess is the adjustment is a one time setting.  You can probably tweak with the arm by setting it back or forward.  To get more rpm you could bend the rod at the top of the arm to be shorter for more rpm.

   The procedure on 14 is probably something like position the governor arm all the way clockwise and the shaft arm counter clockwise then tighten the figure 1 bolt. 

    The way they drew the bottom spring looks weird, 90 out from what it should be.

  

  

Here:

The diagrams for the Honda governor indicate that it's very much similar to the Tecumseh set up.  It can be a bit touchy to set the governor if you loosen the screw that holds the arm onto the governor shaft.  It takes very little movement to make large changes in rpm. 

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).

The tachometer seems correct as it does show 3600RPM at the full throttle on my HS928.  This old HS35 at 3600 RPM does not sound too good so I will have to watch the RPM after getting a brand new governor spring.

MN_Runner, you mean it sounds bad at 3600 rpm?If it is the factory set RPM it should not.What we got into...

It does not sound good.  Whatever I do with the current governor spring, the RPM reads 2280.  I am just wondering if something is fishy with my tachometer.

blumonster wrote:

The part that bothers me is that when it tried to go over 6" of snow, it was having some power issue.  This thing will be too weak for EOD.  I thinking about selling this 30 yr old blower and just break even.

MN_Runner wrote:
It's not the tachometer, or the spring.  The spring will affect how quickly/slowly the RPM changes, but not the governed RPM.

You have to loosen that nut on the governor arm, then slowly rotate the governor arm shaft with a needle nose plier, then tighten the nut up again.  Forgot which way to turn, but it's very touchy.  A little turn makes big changes in RPM.

You are correct.  It is just a lot of work to take the covers off to get that access on HS35 and is a real PITA.  I wish I had diagrams on how to take the covers off so I had an access to the governor.

aa335, here is the part about that nut:

MN_Runner, will just taking the rear cover be enough to reach the governor arm nut?If so it looks easier:

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.

 

Aa355: “The spring will affect how quickly/slowly the RPM changes, but not the governed RPM.”

 

   According to the service manual it does.

 

MN_Runner:

 

   You can try the spring positions which should make an RPM difference.  That is provided the spring has not flabbed out.  If it’s not making a difference then you could get a new spring but before that I’d do what Borat, aa355 and I have suggested which

Is tweak the governor position on it’s shaft for more REV’s.

 

   On your tach.  If it was reading a steady value before and after you moved the governor arm and heard the motor rev higher then it may have been due to a few things.  When you moved it you did not hold it steady for long enough for the tach to sample.  There response is pretty slow.  If you held the arm for several seconds and the tach still did not show an increase then it could be your sensing wire is not wound enough turns or some other setup thing causing a bogus reading.  It could also be a bum tach. 

   Many have a setting for two and four stroke engines.  When set wrong they will sometimes output correct values and sometimes not.  When set right – good values.   

A small suggestion for what it's worth.  On some of the small and older Tecumseh engines.  The way that made adjustments to the Gov rod to increase RPM was to.  Bend the Gov rod a small amount.
(That would be the small diameter rod with the spring on it.  That runs from the Gov arm to the throttle on the carb).  If you put a slight bow in it, it shortens it.  That was the way it was done.
 It's very easy to make very small adjustments .... RPM up or back down.   It's a whole lot easier than messing with the Gov arm attachment bolt.

The adjustments given above for the Gov. are really to set the full open throttle position.  In relation to the Gov itself. 
Making small adjustments can be difficult.  And because there is no throttle control.  As soon as you start the engine it goes to full throttle.  So if you do mess with that adjustment. Be ready to shut it down in case
you went to far.  Or low RPMs won't be your problem.  You'll have larger ones.  If you know what I mean. :)

I will try your ideas first on Wed then I am planning to drill 1 inch hole so I have an easy access to the governor arm shaft.  Once I resolve this RPM issue, the blower will be very good.

blumonster wrote:

It is much easier from the backdoor (rear cover) approach.  I have a full access to the governor and the spring so it will be easier for me to adjust now. Thanks for the diagram.  I will let you know how this goes once I figure out how to increase the RPM.

I purchased one of those tach/hour meters for my Husqvarna snow blower.   It  cost $42.95 US.    The engine is a Briggs, 305, 1450 torque engine.     At full throttle it reads exactly 3600 rpm, 

I tried per aa335, but the governor shaft does not move at all.  It does blow snow ok so it really is not worth adjusting it since it does not sound all that good at higher RPM anyway.

if the governor shaft will not move then you have a problem with the governor.  in order for the governor to control the engine speed it must be able to open and close the throttle plate on the carburator.

MN_Runner wrote:
Since you were able to change engine speed by moving the governor arm, I suspect that the governor shaft is stuck to the governor arm.  You can try spraying a small amount of penetrating fluid at the joint and break it loose.

aa335: "Since you were able to change engine speed by moving the governor arm, I suspect that the governor shaft is stuck to the governor arm.  You can try spraying a small amount of penetrating fluid at the joint and break it loose."

  No.  He has moved the governor arm which should be bound (bolted) to shaft by the 6 x 20 bolt and nut.  The shaft should be turning when the arm is moved.  He says the shaft can't be turned so the arm is not bound to the shaft as it should be.  The bolt is probably loose or the shaft worn. 

  Carlb is right.  That shaft has to move.

NM_Runner:  "It does blow snow ok so it really is not worth adjusting it since it does not sound all that good at higher RPM anyway."

   If it's over rev'ing it won't sound good but worth adjusting.   The governor keeps the engine from over'reving.  It also keeps the rev's constant for any throttle setting.  At full throttle the engine will sag under load.  The governor will sense that and move to increase the carb throttle to get more gas and keep the rev's constant for the load.  Without a working governor an engine will sag when loaded and be pretty useless.

So how do we adjust it? How should MN_Runner proceed?

I sold my HS35 this afternoon.  The governor works and it does maintain the RPM (just not at 4000 like the service manual says) under the load and blows the snow reasonably well.  I just did not want to sink more money and time into this machine than I am willing to invest on a 30 year old machine as the parts are sometime obsolete and not available.  I would have kept the blower if it were upgradeable to GX160 but  the HS35 platform cannot take GX160 as G150 has a lower height.

Your HP formula has a fault, does the term "Torque curve" or "Power curve" ring any bells? You will have a maximum torque at a given speed, after you reach that speed the torque falls off. Were it not for the curve, you should be able to the the motor together until around 5000 RPM, that should put you in the 15 HP range.

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?

Perhaps I will not get one now.  I have no fancy anymore as my one week HS35 experiment was enough.

I guess I will have to wait for somebody else who can help.

MN Runner:

Pick up a used Craftsman/Murray machine with a two cycle Tecumseh engine in it.   Put a string on the governor arm to spin it up and see what it can do.  You'll  find it effective and entertaining.

blumonster,

You have a secret weapon which is your service manual.  Advices from jetberator, trouts and borat are all good - maybe they can do a facetime with you.  So whatever mistake you make on HS35, you will be a pro when you have to fix your HS621.

MN_Runner wrote:
I do applaud you for venturing outside of your comfort zone on this one though.  I think you would have better transition working on a simple two stroke machine like a Toro Powerlite as opposed to a complex HS35.

aa335 wrote:

Thanks for your comforting words.  HS35 is not very easy to open up and perhaps I learned my lessons too. 

MN_Runner wrote:
Those HS35 are the BMW of SS snowblowers.  It is a complex model.  Just looking at the diagrams for the scraper bar and hardware to hold it in place, that's a lot of parts.  Other snowblowers are a lot simplier.

Last year when I worked on the HS621, I took pictures at various steps and keep all the fasteners organized.  It also helps to work on them in warm weather so you're not hurried to button them up for use to clear snow.

Changing the scrapper bar was no fun either and took too much time.  G150 is a nice engine which will outlast the body so you really have to take care of the body.  Hopefully I can keep my 928 in a good shape.

@aa335,

So to be clear, your HS621 is not for sale, right? http://chicago.craigslist.org/nwc/grd/2706687911.html

MN_Runner wrote:
Nope, mine is not for sale.  Too much time and money spent on it to let it go.

aa335: It does kind of look like your garage in the photo....

I did not think aa335 was selling his beloved HS621 and the pictures look so close.  The garage floor was painted in the ad and not sure if aa335 recently painted his concrete floor.

My garage floor is not painted.  I have plans to do epoxy paint the floor, but haven't find the time.  The pictures do look very similar to the ones I took.

A few weeks ago, there was a local CL ad for a HS621.  The seller used the exact picture of my snowblower!  Very misleading!  Gotta be careful of CL sometimes.  What you see is NOT what you get.

MN_Runner wrote:
I have some plans for putting in a GX200 engine with some performance mods that the karting guys do to it, with throttle control and remove the governor altogether.

I'm sure the chassis can handle it.  It's just a matter of time and money.

I read somewhere on the forum that aa335 painted his HS621.It looked brand new on the pictures, not faded like the ones on craigslist ad.

blumonster wrote:
Yes, the HS621 went through a makeover last year.  Mechanically, it was very sound machine, everything was in great shape.  It did have some scratches and surface rust so I took care of it.  All wear items and fasteners were replaced.  The result was near showroom quality.

This is my stable.  More will come, but I'm fairly picky on the who makes the lineup.