Priming 2 Cylinders only

[apkp777]

Hey all,

I am installing my engine fuel primer. I initially was thinking of going with a 4 cylinder set-up, but after running the lines, I am thinking I don't like the looks of it and was considering going with just a 2 cylinder prime (#2 & #4).

Anyone have any input?

[videobobk]

Not a bad idea at all. Some production aircraft use three cylinder priming so that it isn't likely to flood all cylinders. Two should work just as well, IMHO. I find I only need priming when it is below 30*F anyway, and at those temps I usually preheat. A couple of stroke on the throttle will start about anything with a good battery in most conditions.

Bob Kelly

[apkp777]

I am thinking that priming 2 cylinders would be just as effective as 3 or 4. Combine that with preheating in the cold months.

Van's Primer Kit comes for a 2 cylinder setup, they must feel 2 cylinders is sufficient.

Just thinking out loud.

[sprucemoose]

I only ran primer lines to 2 and 4, much easier to plumb. Starts just fine in the cold WI wx.

[apkp777]

Thanks Jeff, great meeting last night. Kind of makes you want to think about flying gyros, or eating gyros, not sure which I'd like better.

[vic syracuse]

I only primed one cylinder on my 7, and it has worked fine through 2 winters, albeit Atlanta winters. Some starts were in the upper 20's after being cold soaked all day.

Vic

[jsharkey]

I primed the two forward cylinders. Worked great so far over a cold NE winter.

Jim Sharkey
RV-6

[alpinelakespilot2000]

So, assuming one is going to prime two cylinder's only, can which two you chose be based simply on where the routing is easiest? For example, is priming #1 and #3 (both on the right) just as appropriate as priming #3 and #4 (one on left and one on right)?

[apkp777]

I am planing on priming 1 & 3 for easy routing. It makes no difference which 2.

[Steve]

I'm with Bob K with no priming system at all. And it gets cold and snowy during those winters in northern Utah. A touch of pre-heat and 2 pumps on the throttle then crank it over. Starts on the 2nd blade every time. My RV6 bud's primer line broke just after the pump (forgot the service loop). He pinched off the tube and ran without the primer for a couple of months and never noticed anything different during engine start.
You'll also be flying sooner.