valve guides

[bcomes]

I have a 36 SV 45 flathead. My big picture problem is no gas getting from the bowl to the intake. It'll only run on starter fluid. I am pressure testing the intake. Both valves closed and a slight amount of air comes out from the top of the lower valve cover on the rear intake. Does this mean the intake valve guide is leaking air? Is a small amount of leakage to be expected?

Brad

[T. Cotten]

Brad!

If turning the motor through slowly does not find a spot where the bubbles stop, then I would first check for certainty if the valve adjustment allows it to fully close.
(I can't remember ever testing valve covers on any marque, but I do remember that Chiefs never have both intakes fully closed at the same time, so I set the regulator and ignored it.)

Still, you should be able to get your palm wet if you hand choke it.
And then get at least the same reaction as starter fluid (but more safely.)

Let us know what you observe,

....Cotten

[bcomes]

Sorry for the delay in feedback but I only have a few hours a week that I can work on my bike. That will change in April when i retire.

I'm pretty certain I found crank positions where both intake valves were closed. The only place I could get bubbles from the pressure test was out of the joints in the valve covers. I reasoned that this was not ideal but probably ok because the critical "pull" of air through the carb is when the intake valve is OPEN and the piston is on its way down. In this case, very little air would enter up through the valve guides as the carb is the path of least resistance.

So, I put it all back together and she ran better than ever. The fuel filter area at the bottom of the carb had some small particles in it so I'm concluding that something got into the carb and plugged fuel flow through it. I've coated the right hand tank with Crosley's tank sealer (cool stuff; it's like large quantities of thinned down JBWeld - I'd recommended it for contanimated tanks) so I don't expect any more crud in the fuel filter area.

I'm rolling again. Thanks!

Brad

P.S. It's been so long since I worked with carbs that I forgot about hand choking it. Thanks for the pointer on that. Starter fluid is now a last resort.