Interesting observation Richard, but...
I wonder if it might make more performance sense to index the plug gap
toward the exhaust port since that is where the extra air/fuel mixture
probably comes from just before the plug fires.
Or does the mixture from the transfer ports still dominate?
If you are off the pipe RPM that should be true.
While there is a slight bias in all 4 transfer port directions towards the
intake side of the chamber, all 4 transfer ports are totally closed off by
the rising piston top before the exhaust port is 1/2 closed.
So, anybody else like the intake side of a piston ported motor like the Kaw
for best performance from indexing?
Anybody got a test report from any source that says what they ought to be
indexed towards?
Chuck
From: "Richard Schmidt" <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: <[email protected]>
Subject: Re: [F500] Indexing
Date: Sun, 15 Jul 2007 21:04:15 -0500
Chuck,
I guess I am not making myself clear. The plug doesn't see the carb, it's
just that this is the direction of the piston wash that I saw.
I just looked at one of the Kawasaki cylinders and I can see why the piston
wash is the way that it is. All four of the transfer ports direct the
fuel/air mixture towards the carb side of the cylinder. This makes sense as
this then would flush out the burned gases towards the exhaust port.
Richard
----- Original Message -----
From: "Chuck Voboril" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, July 15, 2007 2:08 PM
Subject: Re: [F500] Indexing
> Richard,
>
> Thanks, I was curious where you guys think you ought to be indexing your
> plugs.
>
> You say "aim the gap to the carbs".
> Does anybody else agree with that and why?
>
> When does the sparkplug gap see the carbs or intake port?
>
> Chuck
>
>
>
>
>
> >From: "Richard Schmidt" <[EMAIL PROTECTED]>
> >Reply-To: [email protected]
> >To: <[email protected]>
> >Subject: Re: [F500] Indexing
> >Date: Sun, 15 Jul 2007 13:56:31 -0500
> >
> >Chuck,
> >
> >Look at the pattern on your plugs. A better indication is to look at
the
> >top of your piston. The part of the piston that is washed clean is the
> >direction you want to face your plug.
> >You want the open side of the plug facing the direction of the incoming
> >fuel/air mixture. On the Kawasaki, that direction was towards the
carbs.
> >
> >The Rotax must have a better swirl pattern as I am not seeing pattern
on
my
> >plugs and I don't have a tool to inspect the top of the piston.
Usually
> >the
> >piston inspection is conducted after a melt down. I don't plan on any
of
> >those soon.
> >
> >Richard
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