Hi
Iam somewhat new to the garden tractor side of this board. I have had a 1971--??? 70 JD ..7HP tecumseheh lawn tractor that I inherited from my dad in the shed for 4-5 years. I decided today to see what it needs and started out with a compression test. It shows 70 lbs. Is this enough to get it to run?? What would it have been when new?
Appreciate any advise you can give.
Thanks
Jake

In my opinion, Jake, 70 lbs. would be fine. Actual compression figures for these small engines are rarely supplied in the tech manuals. It's been 3 years since I had a VH70, ( vertical shaft, cast iron block engine for a 70) apart, and don't remember if it had a mechanical compression release on the cam. When they have a compression release, it will give low readings at under 500 RPM, or so, cranking speed.
Now this is just a guess, but I wouldn't expect more than 90lbs. on any stock 7HP engine of that vintage, in new condition. If you have good spark, a clean, properly adjusted carb., and good fuel, she'll run. If it smokes a lot and uses much oil, give it a new piston and rings and lap the valves if you want to do much mowing with it.

tommyhawk

QUOTE (tommyhawk @ Feb 20 2006, 10:41 AM)

In my opinion, Jake, 70 lbs. would be fine. Actual compression figures for these small engines are rarely supplied in the tech manuals. It's been 3 years since I had a VH70, ( vertical shaft, cast iron block engine for a 70) apart, and don't remember if it had a mechanical compression release on the cam. When they have a compression release, it will give low readings at under 500 RPM, or so, cranking speed. Now this is just a guess, but I wouldn't expect more than 90lbs. on any stock 7HP engine of that vintage, in new condition. If you have good spark, a clean, properly adjusted carb., and good fuel, she'll run. If it smokes a lot and uses much oil, give it a new piston and rings and lap the valves if you want to do much mowing with it. tommyhawk

Ho Tommyhawk
Thanks for the good information I appreciate it.
I will try to have this old girl cutting grass by spring. -10 celcius here today
Jake

he is rite there is a "decompression" valve in it. i know cuz wen i bought my 70 the engine was blown up. then i took it to get it fixed and he said the "decompression valve " was gone. so now needless to say it is real hard to pull over. ooooo yea the valve is no longer avaliblee. sss yea i would say 70 is danm good for a stock 7 horse but i realy couldnt tell you.