[AT] Compression values and range

[Ed Stewart]

Here is a little tip worth trying if you suspect carbon built up on 
valve seats. My dad showed me this about fifty years on a F-20 that you 
could hear compression leaking out the exhaust when pulling the crank 
slowly through compression. I have done this many times since. Start the 
engine allow it to thoroughly warm up, increase the throttle and squrit 
water into the carb at a rate that does not kill the engine, you will 
have a bunch of steam coming out the exhaust. The water and resulting 
steam cleans any carbon buildup from everywhere in the combustion 
chamber and many times I have seen lower compression rate climb 
considerably. After he showed me the ol F-20 didn't hiss by the valves 
anymore and ran a lot better. I have done this with cars, tractors, 
lawnmowers and several hitnmiss engines. Ed

Dean Vinson wrote:
> Mike Sloane wrote:
>
>   
>> Based on everything I have read about this tractor's problems, I would 
>> have to say that it either has very low compression or weak spark under 
>> compression. I had a Ford N that was very hard starting, and it turned 
>> out that the rings were broken on two of the pistons. It would run, once 
>> I got it started, but a compression check showed two cylinders with about
>> 30 pounds compression. Burned valves can also cause poor compression.
>>     
>
> Mike, I do have significantly lower compression in two cylinders than in the
> other two.  #1 and 2 are at 115 and 118 psi respectively, but #3 and #4 are
> at 90 and 105.  90 seems mighty low compared to 118 but it's nothing like
> the 30 in your example.
>
> What do those numbers tell me?  Is 90 bad?  Or is the fact that it's
> different from the other ones bad?  I assume the lower numbers mean worn
> rings but probably not broken ones, and the tractor ought to run fine for
> what little work I'm going to ask of it.
>
> Dean Vinson
> Dayton, Ohio
> www.vinsonfarm.net
>
>
>
> _______________________________________________
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> Remembering Our Friend Cecil Monson 11-4-2005
> http://www.antique-tractor.com/mailman/listinfo/at
>
>   

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Ed Stewart(using DSL connection)
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15851