I borrowed (Ok, Ok, I stole it

) an idea from Painlesstom that he had posted some time back regarding a Fresh Air Intake for the old Honda engine. I had noticed when operating at top speed, after a few minutes my speed would drop off by 1~1/2 mph. I assumed rightly or wrongly that the air in the engine compartment got too hot and a source of cool fresh air directly into the carburetor might solve that problem. I picked up a couple of things at the local HW store; a length of 2” PVC pipe, a 2” PVC flexible coupling, and a 2” 90-Degree PVC Flexible Elbow Coupling.
I removed the engine air filter top cover and filter. Using a razor knife, I trimmed the flexible coupling to fit the inside contour of the bottom half of the air filter enclosure. I put a couple of drops of super glue on the top of the coupling then carefully placed the engine cover back on in place until the super glue hardened. When I removed the engine cover, the coupling was lightly glued to the cover and I was able to scribe a circle on the downside of the engine cover through the inside of the flexible coupling. I pulled the coupling loose then following the scribed line, cut a ~2” hole through the engine cover so that a short length of the 2” PVC pipe could go through it.
I then repositioned the previously trimmed flexible coupling back onto the bottom half of the air filter enclosure, reinstalled the engine cover, then pushed a short length of PVC pipe down into the flexible coupling on the carburetor. With a little epoxy I permanently glued the PVC pipe to the engine cover to prevent it from turning thus keeping the trimmed coupling always aligned with the contour of the bottom of the air intake housing. Next I positioned the 90-degree flexible elbow over top of the PVC pipe and tightened all the SS clamps.
It worked great. I no longer had any speed drops while running at full throttle. In a heavy rain, I can turn the top 90-degee elbow away from facing the front. I suspect a larger fresh air intake would help keep the engine cooler while still providing cool fresh air to the engine now that I see what Painlesstom has been doing.
Nonetheless, thank you Painlesstom for another great idea.
