Hello all! My dad has owned his RV7 for 8 years now (had 300 ish hrs on it when we bought it) and we?ve had a hot weather issue from the start. The PO, the guy who built it, said that once in a while it needs the fuel pump when on the ground to help prevent vapor lock.
So it?s an IO360 with dual P mags.
During NC summers and on the ground, it runs great while warming up. But once warm, like after a flight, we have problems. Yesterday was a good example. A buddy of mine and I flew it to a grass field glider airport where I fly the tow plane. 10 minute flight in the morning, then it sat in the sun all day while I towed. At around 4 pm (over 100 degrees on the field), I jumped in with a friend to give him a ride. I did a cold start procedure and it fired right up. We took off and flew around for less than 10 minutes at 1500 ft and at about 20? and 2400 RPM. Came in and landed. Now I needed to do a quick turn around since one friend was getting out and the other was getting in. Hot starts with such a quick turn around are nearly impossible with this thing. So I decided to keep the engine running. I had it runnng at about 900 RPM and leaned out. Friend A jumped out and friend B climbed in. He was just about in when the engine started to die. It went from running smoothly then it sounded like I had pulled the mixture to off. That quick. I turned the fuel pump on, shoved the mixture in and added throttle. I just barely kept it alive. From there it was running like **** and there was nothing that I could do to make it happy. I told my buddy that we had to hurry up and go. I had to keep it at about 1300-1400 rpm just to keep it running. As soon as I added power for take off, it smooths right out and runs perfectly.
So we fly 30 minutes to get BBQ. Land and shut it down 45 minutes later I did a hot start, short taxi, and took off. It ran fine on the ground. Flew 30 minutes home, low pass, and landed. Taxing in, the engine was idling ok, but surging. Again, this has to do with the hot weather on the ground issue.
It just had an annual and the mechanic (familiar with RV?s) insulated the fuel lines to try to help his problem. But it made no difference. Everything I?ve read says that you might need the fuel pump to help with vapor lock until the cool fuel is pulled through the lines then you don?t need it. Our issue seems to be different. It?ll be idling just fine then all of a sudden it?s trying to quick and it won?t stop until you either take off or shut it down and let it cool. If it actually quits, it won?t restart until it cools.
Again, this is only an on the ground issue. Like vapor lock. But how could a 10 minute flight with just a few minutes of idling cause this? Something else is going on and we can?t figure out what. The problem seems to be getting worse.
I?m sorry this was so long, I wanted to give as much detail as possible.
Any help with be appreciated.
Steve
So it?s an IO360 with dual P mags.
During NC summers and on the ground, it runs great while warming up. But once warm, like after a flight, we have problems. Yesterday was a good example. A buddy of mine and I flew it to a grass field glider airport where I fly the tow plane. 10 minute flight in the morning, then it sat in the sun all day while I towed. At around 4 pm (over 100 degrees on the field), I jumped in with a friend to give him a ride. I did a cold start procedure and it fired right up. We took off and flew around for less than 10 minutes at 1500 ft and at about 20? and 2400 RPM. Came in and landed. Now I needed to do a quick turn around since one friend was getting out and the other was getting in. Hot starts with such a quick turn around are nearly impossible with this thing. So I decided to keep the engine running. I had it runnng at about 900 RPM and leaned out. Friend A jumped out and friend B climbed in. He was just about in when the engine started to die. It went from running smoothly then it sounded like I had pulled the mixture to off. That quick. I turned the fuel pump on, shoved the mixture in and added throttle. I just barely kept it alive. From there it was running like **** and there was nothing that I could do to make it happy. I told my buddy that we had to hurry up and go. I had to keep it at about 1300-1400 rpm just to keep it running. As soon as I added power for take off, it smooths right out and runs perfectly.
So we fly 30 minutes to get BBQ. Land and shut it down 45 minutes later I did a hot start, short taxi, and took off. It ran fine on the ground. Flew 30 minutes home, low pass, and landed. Taxing in, the engine was idling ok, but surging. Again, this has to do with the hot weather on the ground issue.
It just had an annual and the mechanic (familiar with RV?s) insulated the fuel lines to try to help his problem. But it made no difference. Everything I?ve read says that you might need the fuel pump to help with vapor lock until the cool fuel is pulled through the lines then you don?t need it. Our issue seems to be different. It?ll be idling just fine then all of a sudden it?s trying to quick and it won?t stop until you either take off or shut it down and let it cool. If it actually quits, it won?t restart until it cools.
Again, this is only an on the ground issue. Like vapor lock. But how could a 10 minute flight with just a few minutes of idling cause this? Something else is going on and we can?t figure out what. The problem seems to be getting worse.
I?m sorry this was so long, I wanted to give as much detail as possible.
Any help with be appreciated.
Steve