OK....I'm going to make this as simple as I can, my pc time is limited, and
I don't have the time to teach basic mechanics and engine tuning over the
Internet.
If you look at MACCA 68's post you will see he had the same issue -
main needle 6 - 7 turns open. I dont agree with the way he 'solved' the problem
by closing off the muffler outlet - this is unnecessary. Assuming there is nothing
unusual with his fuel plumbing and tank position I believe he still hasn't got the
idle needle lean enough. THIS IS THE KEY to setting up these carbs.
If a carb has to be set at 6-7 turns out
it isn't getting enough fuel.
If an engine is not getting enough fuel (too lean)....leaning the carb out
further will not remedy the situation !!! You are heading the wrong way.
If the engine is
not getting enough fuel (too lean) you must
richen
the engine.
In the case of this engine, they suffer from a large exhaust muffler with no baffle
which results in slightly lower pressure to the tank. My engine suffered from the
exhaust nipple needing to be drilled to clear out the "flash" because it was
restricted
causing a further loss of pressure to the tank. The nipple feeding the carb inlet
wasn't perfect either, and the fuel inlet to the spray bar was missalighned, and
had about a 40% restriction. I had to drill that out too. Have you read this thread ?
Having corrected all these problem areas
allows enough fuel to the needle,
so that a proper adjustment can be made.
And I do, BTW, have one of these engines, and I have tuned it to perfection.
My engine, FWIW, was set too lean on the low end and was bogging in transition.
I just checked my engine, I ran it a couple weeks ago...it has a bent wire on the
main needle making it very easy to count the turns....
....
two turns, plus two clicks. My engine is obviously correct.
Please, rather than trying to tell everyone that they don't know what they are
talking about....won't you read up a bit on carb's ? Trust me, we are so
very
happy that you didn't have an engine with all the problems we, in this thread have had.
By simply tuning
your engine correctly, you were able to get it running
correctly....that is wonderful.
Thank you for your contribution.
Flyboy Dave.