Bob,

Use foam from from the YS engine box. You can use 5min epoxy to fix it to the cowl. Make ducting that goes right to the front of the engine directing it to the head. Specifically as much of the pump and pushrod tubes as possible. The idea is to make the air from the front only go through the engine and not allow it to bypass around. Any spot bigger than 1/4" it too much gap. This will help tremendously with cooling. The 160 doesn't run so hard, and it has less metal mass to heat soak when running. The thinner the metal the better the heat transfer. Also you were running your 160 in cooler temps last fall and this spring.


If you pump is not 100% exposed....It needs to be. I got home and its been over 115degs the last week. I flew a couple days ago and then added some foam to my model it works pretty well. I did this last year also.

Next thing is your pipe. Not sure what pipe you are using but if its an ES pipe I would bet money a baffle is blown up and is plugging it up. I ran the ES pipes and could get almost a year out of them in Colorado when I first started with them. They are good and light and the sound is excellent. However in AZ I was down to about 15 flights on a new one and could plug it up or blow it up. If they didn't blow up in 15 flights they would start to leak. I was the only guy having this problem so I just took it that I was idiot. I switched to hatori, and Asano and didn't have any trouble after that. Now I just run the Hatori stuff. Saves me head aches in trying to decide if the pipe a problem or the engine. I struggled with engine problems for 6 months in the AZ heat and finally found out it was the pipes.

Depending on the fuel you have used in the past too it could be that an older pipe could have some carbon build up and it would cause more restriction and make the engine run hotter. This can happen over time and you would not notice it...Just that an engine goes bad...and you replace it then that one doesn't work for beans and you start to question why are you having troubles when its not the engines fault. Its a combo of colling and a restricted pipe.

Troy Newman
Team YS