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Re: Problems at 4500 RPM

To: 76tr6@optonline.net (Seth Glassman)
Subject: Re: Problems at 4500 RPM
From: tr6taylor@webtv.net (Sally or Dick Taylor)
Date: Fri, 20 Jun 2003 17:38:02 -0700 (PDT)
Seth---I'll throw out a couple of "not likelys" at the front of my
reply, since it sounds like your problem is sort of unique. 
Any chance that your tach not registering the correct rpm? You can
verify this when cruising in second gear, as the rpms should read very
close to what the speedo reads.  i.e. 4,000 = 40 mph.

Check to see that your (I'm assuming a 2") SU air valve raises up around
1-1/2 inches with the throttle opened. You can check this by taking off
the damper cap and placing a round stick, or ball point pen with a scale
marking on the side. Use a pen wrapped in masking tape with increments
every 1/8". First mark at idle speed will be even with the top of the
carb, where the cap was just removed. The 12th mark should be seen when
the engine pulls the air valve up. (Not as difficult to do as I'm making
this sound)

The needle used in you SC installation should be tapered from .121 down
to .070 to get the proper amount of fuel. If it's not, write back for
more choices here.

Be sure that your ignition is advancing from its idle setting to at
least 26 deg. when revving the engine to 3,000 rpm. 

Here's another long shot...Be sure that "0" on the timing pulley is
really TDC on the crank. (Or within a couple degrees)

Long shot #3...The cam isn't opening the valves far enough. Measure
valve movement from closed, to open. Compare to what the "lift" should
be.  .300 inches?
Or the valve timing is way off...

At this point I couldn't tell you if it's lack of fuel, or not enough
ign. timing at the 4500 limit you're up against. It would be more
rewarding to find the problem yourself. Short of self abuse, run that
buggy over to Mitch's. He doesn't have anything to do now that his car
is back on the road! (Snicker)

Dick

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