I bought a couple of these as was suggested previously to check the RPMs on my Craftsman #247.88790.

Digital Engine Tach Tachometer Hour Meter Inductive for Motorcycle Motor FC0 | eBay

According to the manual on page 31-32 it lists the Engine as #LA318SA-156554, with everything I have read (various Tecumseh manuals) online it keeps referring to the Tecumseh microfiche page 30 for RPM settings. As it goes that is hidden somewhere inaccessible on the interweb.

Using the above meter I have the following settings on my unit without the adjustable carburetor.

Full throttle (after warmup) 3450rpm
Low throttle (No Load) Idle 1650-1750 rpm

Running thru the gears without using the auger it runs:
1st -3rd gear @ 3200=3300rpms
4th-6th gears @ 3300-3400rpms

Running thru the gears with the auger but NO snow throwing (we have no snow!) it runs:
3400 no matter what gear I put it in

I did not check the RPMs in reverse at all.
It sounds good...No hesitations, No sputtering, No backfiring, No surging.

I am willing and very happy to leave it alone UNLESS the gurus here tell me I have something way out of whack. I don't want to blow this up....

These engines typically top out at 3600 but I like to keep them as low as I can to increase longevity. I think your numbers look OK.

your "unloaded" rpms look ok to me, plz post back if it snows and you get a chance to see what happens under varying loads.

Your machine, your choice. Here are some vids to see how to go about adjusting it.

https://www.google.com/search?q=dony...ing+high+speed

I have an 3 yr. old Ariens Pro and recently installed the same tach. My RPM have never reached 3600 either. I'm running at about 3300.
Interesting.

I'd like to have the max available and then you can chose to run it anywhere you feel comfortable with.
Just my

3600 RPM is whats listed in the service manual at the following link:\

http://previewer.org/?pdfurl=1qeXpur...trS25PkzMuSreY

Running it a bit slower is probably a bit easier on the engine, but you will lose a bit of throwing distance due to slower impeller speed. All the other figures look ok. Be more interesting to see how well the governor does holding it at or around 3400 when its tossing heavy snow.

Of course, there is another school of thought here. If you baby that engine, then it will never wear out and you won't have an excuse to get a new/different snowblower. When I get tired of an engine, I bend the governor spring so it revs to about 6000 rpm, and then after about 4 minutes, you get to go shopping

I'm using the same Tach on a similar if not same engine, and mine seems to do quite well between 3450-3500.

t40lanman - thanks for the confirmation of 3600, I thought that I heard that somewhere

nwcove - Thanks and will do, I know my luck is running out!

Kiss4aFrog - Thanks for the video link, Have watched a few of his videos and he is very helpful. As I stated I really don't want to blow this up.

pfn - I think I can adjust it higher but not sure I want/need to....

Kiss4aFrog - I agree know the limits then choose.....

skutflut - I have read that manual and still cant find the "suggested" RPMs. They describe how to measure the RPMs when they are at a certain voltage...etc not really what I was hoping for but thank you for providing the link.

GoBlowSnow - Thanks for your confirmation, it appears as though my settings are inline and not something to worry about.

I am going to leave it as is and report back when I get to throw some snow

Thanks to everyone for providing me the links and opinions .... I appreciate it!

Opfoto said... "pfn - I think I can adjust it higher but not sure I want/need to....".

I'd like to have something to check my tach against. I ran my machine yesterday to see what it read with no load. I couldn't get a good read as the tach was all over the place. It wouldn't settle on any number long enough. I don't recall having that problem when I was moving snow. I wonder if the tach as issues.