[AT] timing a cub

charlie hill chill8 at suddenlink.net
Thu Jan 31 12:30:46 PST 2008


Hi George,  I knew you would agree with what I said.  I think we've had that 
conversation before.  I wasn't trying to discount the wisdom of doing it by 
the book.  I was only trying to point out that these old engines are fairly 
forgiving and that if it sounds right it probably is right.  In the example 
that started this thread a "flat spot" in the throttle response is 
mentioned.  Assuming that the flat spot is caused by the timing being off it 
is really a good thing because it gives your ear something to go by.

Charlie


----- Original Message ----- 
From: "George Willer" <gwill at gwill.net>
To: "'Antique tractor email discussion group'" 
<at at lists.antique-tractor.com>
Sent: Thursday, January 31, 2008 10:19 AM
Subject: Re: [AT] timing a cub


> Charlie,
>
> My earlier reply was quoting the IH manual method.  It does result in very
> slightly retarded timing for safety reasons (hand cranking).  It's hard to
> beat the results of an experienced mechanic timing by ear.  The light is
> really a substitute for experience on Cubs.
>
> Last summer before our Cub Tug we tested my special Cub on a dyno hoping 
> to
> tune it to the max.  The special carb with adjustable main jet (the IH Cub
> carb is non-adjustable) and the timing were both set by ear.  According to
> the dyno neither setting could be improved.  It won the first heat.
>
> Larry Dotson was reading the dyno.
>
> Some day we'll discuss the carburetor...
>
> George Willer
>
>> Subject: Re: [AT] timing a cub
>>
>> Or you could use my method.  Loosen the distributor and give it a little
>> twist and see if the hesitation (flat spot) goes away.
>>
>> Charlie
>> ----- Original Message -----
>> From: "Larry & Barb Dotson" <dotson at loganrec.com>
>> To: "Antique tractor email discussion group" <at at lists.antique-
>> tractor.com>
>> Sent: Thursday, January 31, 2008 8:13 AM
>> Subject: Re: [AT] timing a cub
>>
>>
>> > Lew,
>> > For 16 ddegrees advance, the 2nd timing mark should be approx. 5/8 inch
>> > ahead of tdc.
>> > You want to be sure the points are set at .020" gap before timing. Also
>> > rev
>> > engine to 1500 rpm
>> > to bring all the advance in when timing with a light.
>> >
>> > Larry Dotson
>
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