A few days ago, I posted a thread requesting a carburetor part number for my3 hp Lightwin. Members at this forum kindly responded with the information I needed and I ordered a new high-speed nozzle. While waiting for the nozzle. I checked compression, and it was low: 47 in one cylinder, and 50 in the other. I had a new head gasket as part of the kit I ordered to refurb the motor, so I pulled the head. Since I had a few days before the new part arrived, I sprayed penetrating oil in the cylinders and spun the motor every day or so in the hope that any sticking components might be freed. When the new nozzle arrived, I installed it, and the head. I surfaced the head with sandpaper laid on a plane of glass, and block sanded the mating surface as well. I reinstalled the head with the new gasket and torqued the bolts to around five or 6 foot-pounds. That seemed low, but I found this value (and bolt torque order) on another thread in this forum.
Compression was now 40 psi. I didn't know what else I could do to fix it, so I decided to try the motor anyway. It actually runs pretty good, however, as I ran it in a bucket of water with the silencer removed, I noticed what looked like water coming back through the carburetor after it had been running for a while.
It makes sense to me that I have a leaking head gasket. However, I tried to be pretty careful when I surfaced the head and mating surface. Are there any other conditions that could cause these problems?
I have a new head gasket on the way. Any suggestions for what I could have done wrong the first time?
Thank you!
Compression was now 40 psi. I didn't know what else I could do to fix it, so I decided to try the motor anyway. It actually runs pretty good, however, as I ran it in a bucket of water with the silencer removed, I noticed what looked like water coming back through the carburetor after it had been running for a while.
It makes sense to me that I have a leaking head gasket. However, I tried to be pretty careful when I surfaced the head and mating surface. Are there any other conditions that could cause these problems?
I have a new head gasket on the way. Any suggestions for what I could have done wrong the first time?
Thank you!