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Author Topic: CH25 timing advance  (Read 6267 times)

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Offline flatlanderfornow

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CH25 timing advance
« on: February 07, 2012, 10:32:44 pm »
How much can I advance the timing before I run into trouble?  Stock ungoverned engine,
pump gas, going into a puller. I'm thinking 5deg or so, but more if I could.  No sam box.
We pull 100', so the engine doesn't have to stand it for long.
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Todd Potter
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Offline FlatheadPuller

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Re: CH25 timing advance
« Reply #1 on: February 07, 2012, 10:41:33 pm »
We run 35* btdc in our 45. But its far from stock. Also on pump gas. Roller motor.
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Dennis Bazzett
Grandville Michigan

Offline flatlanderfornow

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Re: CH25 timing advance
« Reply #2 on: February 08, 2012, 08:43:13 pm »
I'm thinking 28-30 to start, may go a little more if it holds together.
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Todd Potter
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Offline TinRabbit

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Re: CH25 timing advance
« Reply #3 on: February 12, 2012, 08:57:02 am »
With a pure stock engine from the factory, I have popped in a 4 degree offset key & found an increase in tq & a broader power band, then had to drill the jet out because the things wanted more fuel. The triad flywheels (if I remember correctly) have a keyway in them that is about 12 or 15 degree advanced from what the commands are.
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Kyle

Offline flatlanderfornow

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Re: CH25 timing advance
« Reply #4 on: February 12, 2012, 12:01:08 pm »
How much did you go on the jets?  Main jet or both?  I've noticed the Kohlers seem
to be fussier on jetting than a Briggs. 
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Todd Potter
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Offline TinRabbit

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Re: CH25 timing advance
« Reply #5 on: February 12, 2012, 04:38:35 pm »
1 engine liked having jet drilled out just .009 more, next needed more & 1 I remember wanted it out another .035 more, that's a big swing in jet sizes.
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Litterbox Engine
Kyle

Offline flatlanderfornow

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Re: CH25 timing advance
« Reply #6 on: February 14, 2012, 08:35:38 am »
Sounds like I need to have a selection.
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Todd Potter
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Offline Caudy155

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Re: CH25 timing advance
« Reply #7 on: February 14, 2012, 09:37:15 pm »
You bump up the flywheel timing id pop the cam ahead a tooth also... made a world of difference on my intek... don't see why it would make a difference on engine brand... af course if your pullin you prolly want more power higher in the rpms
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Offline fordman21

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Re: CH25 timing advance
« Reply #8 on: February 21, 2012, 12:04:09 pm »
It will make a very big difference between engine brands, because the tooth count on the cam gear will be different. Going a full tooth on a command is way too much.
I would run about 35 degrees for the ignition even with a stock ungoverned engine.
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Ryan Kerr  519-332-9532
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Offline flatlanderfornow

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Re: CH25 timing advance
« Reply #9 on: February 21, 2012, 08:39:00 pm »
Regular or Premium?  Some of the premium around here has no ethanol.
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Todd Potter
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