VW Engine Hiccup

[N747VG]

Hello Everyone.

Had an issue arise with my sonerai today.

If i throttle up too quickly the engine will hiccup for a second and then keep running fine. Seems like it may be starved of fuel for just a second. i'm hoping it's just a fuel filter which i'm going to change tomorrow but has anyone had a similar issue.
I had the thought that it might be running to lean. There's no mixture adjustment in the cockpit.

Thank you.

[Dana]

If it runs fine at full throttle it's unlikely to be the fuel filter. Look at the accelerator pump, if you have one... what kind of carburetor is it?

[N747VG]

If it runs fine at full throttle it's unlikely to be the fuel filter. Look at the accelerator pump, if you have one... what kind of carburetor is it?

No accelerator pump. It’s a revmaster revflow carb


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[Dana]

It didn't do it before?

[N747VG]

It didn't do it before?

No. I worked on it today and it seemed to run a lot better.


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[Dale Andee]

Without an accelerator pump that response, at least to me, would not be unexpected.

I was taught to slowly roll the throttle on and off.

It may be different with various OATs or whether the engine is completely warmed up or not.

[flyrgreen]

The Revmaster Revflow "carb" is not a carburetor, it's a Throttle Body Injection. A poor-mans fuel injection. No floats, no float bowl, no jets, etc. A good solid unit, little to go wrong. But it does have the idiosyncrasy you mention. Can't jam that throttle from idle; once flying, you can. Like any small passage for fuel, some cleaner now and then is helpful, especially if the fuel has been sitting for awhile.