yong heng noise

[danny5692]

My 18 month old yong heng seems to make more noise than before.

I have had the cilinder of and checked for any wearing or loose parts. One thing i've noticed was the top of the small piston had come loose.

I thightend it and assembled it, and it seemed to make less noise.

But after 5 minutes the loud sound came back. The small piston is still tight now.



Anyone anymore suggestions? It still keeps good pressure. 

 

[SteveKralsAround]

How about a video , so we can hear it too .

 

[biohazardman]

The second stage piston needs to have some high temperature locktight applied so it will not back off again.

The second stage piston came loose, on one of mine also, after only a couple of hours of run time. Very poor QC and no locktight applied at the factory. But it beat itself against the top of the head and destroyed itself in a very short time. So, I had to replace it. Cost me $12 for the part. That took care of most of the extra noise I had been hearing.

After forgetting to put oil in it when I was done replacing the piston I ran it with no oil, in the crankcase, and filled my Impact with it. 

I then filled it with oil and it ran fine for over a year. But after that it began to get noisy. So, I replaced the rod but that only got rid of half of the noise. The other half, which was a considerable amount of noise and sounded really bad, was just loose cover screws.

The suction cup feet are famous for coming loose. I really don't think they tighten them much at the factory. They make quite a racket when the thing is running as well.

You have to take the rear cover plate off to get at the two nuts for the rear feet.

Good luck in your journey with the Yong Heng noise.

 

[danny5692]

Thanks for the information. You were right about the second piston, that was the problem. I have tightened it well and problem solved.

 

[biohazardman]

Good deal it's not always that easy.