06-04-2018, 12:10 PM
brian,
teching out anything requires you follow a straight path .
starting on one side and working to other is best path
so confirm you've checked each section for possible issues.
on fuel issues you need to check fuel flow from tank to carb first.
occasionally theres a tank filter in the outlet valve on tank that gets clogged.
next you need to narrow down what isn't working
since engine one fired off perfectly remove carb and install on engine two.
you already know that carb is good.
while installing be sure pulse hole lines up.
if engine fires you have a carb issue.
if engine doesn't fire it may be something else.
if you know how to do pop off test carb as that's the fastest test to confirm function.
my best guess is you've probably forgotten something.
when you built the carbs did you flat sand/polish all the flat surfaces?
if not do that first.
did you soak carb gaskets in oil to swell them that often causes micro leaks.
if they've sat a while resoaking gaskets often fixes issues.
is your pump diaphram still good?
like ted said check gasket order.are the gaskets stacked in the correct order. this is usually the #1 issue on failed carbs freshly rebuilt.
if the gaskets aren't new a new gasket set often eliminate odd issues.
did you pull the weltch plug and check the low idle to be clear?
if you're nervous about pulling the weltch plug you can check it by removing idle adjustment needle and gently blowing air down threaded area.
if air comes out both the tiny holes you are all set.
if it doesn't you'll need to clear those two passages.
another thing to look for is if the diaphram is punched correctly.
on some brand new ones i've found the fuel inlet hole to be as much as 25% covered by overlap.
this is caused by the hole being off to the side a little. oval the hole so the opening is open completely.
that's enough for now get back to use with results.
D
teching out anything requires you follow a straight path .
starting on one side and working to other is best path
so confirm you've checked each section for possible issues.
on fuel issues you need to check fuel flow from tank to carb first.
occasionally theres a tank filter in the outlet valve on tank that gets clogged.
next you need to narrow down what isn't working
since engine one fired off perfectly remove carb and install on engine two.
you already know that carb is good.
while installing be sure pulse hole lines up.
if engine fires you have a carb issue.
if engine doesn't fire it may be something else.
if you know how to do pop off test carb as that's the fastest test to confirm function.
my best guess is you've probably forgotten something.
when you built the carbs did you flat sand/polish all the flat surfaces?
if not do that first.
did you soak carb gaskets in oil to swell them that often causes micro leaks.
if they've sat a while resoaking gaskets often fixes issues.
is your pump diaphram still good?
like ted said check gasket order.are the gaskets stacked in the correct order. this is usually the #1 issue on failed carbs freshly rebuilt.
if the gaskets aren't new a new gasket set often eliminate odd issues.
did you pull the weltch plug and check the low idle to be clear?
if you're nervous about pulling the weltch plug you can check it by removing idle adjustment needle and gently blowing air down threaded area.
if air comes out both the tiny holes you are all set.
if it doesn't you'll need to clear those two passages.
another thing to look for is if the diaphram is punched correctly.
on some brand new ones i've found the fuel inlet hole to be as much as 25% covered by overlap.
this is caused by the hole being off to the side a little. oval the hole so the opening is open completely.
that's enough for now get back to use with results.
D
Dave L.