Eu1000 rebuild update from OP: I have been running this unit since the rebuild. I have put over 100 hours on it since (per hr meter). I usually do the oil changes every 50 hours, but I was having to add oil about every 12-15 hrs. So it is still using oil. I suspected the cylinder was worn. I thought of selling this one cheap and getting another used one, but a used one might also have issues.So I looked into another rebuild, replacing the cylinder. I found that this rebuild cost and the cost of the previous build totaled less than $400, and used EU1000’s in my area go for $500 and up. So I decided to do it. I also purchased a bore measuring tool so I could check the old bore. I had a bore measuring tool years ago but I sold it. So I finished the build, I did find the bore on the old cylinder was 0.002” over size at the piston pin axis at mid stroke. The piston skirt measurement was okay. I ran it gently through the first 10 hours, Honda's recommended first oil change interval, and ran it another 50 hours (my oil change interval) and had no oil usage whatsoever! I have come to some conclusions from this experience: I have seen EU2000 specs. in the past that list the cylinder being cast iron (sleeve), but the 1000 does not list cylinder construction, and it did not appear to have a sleeve in it when when I had it torn down. I suspect the cylinder is aluminum with a “hard coating” as I am finding in my research. IMO, I don’t feel the EU1k cylinder would last as long as a EU2000. I do read about some EU2k’s with 5000 hrs! My EU1000 had over 1300 hrs (per hr meter) and that may be about it’s limit. If I were to rebuild one again, with high time, I would just replace the cylinder right off. It’s cheaper than buying a used EU1k, and now I basically have a new engine!
Eu1000 rebuild update from OP:
I have been running this unit since the rebuild. I have put over 100 hours on it since (per hr meter). I usually do the oil changes every 50 hours, but I was having to add oil about every 12-15 hrs. So it is still using oil. I suspected the cylinder was worn. I thought of selling this one cheap and getting another used one, but a used one might also have issues.So I looked into another rebuild, replacing the cylinder. I found that this rebuild cost and the cost of the previous build totaled less than $400, and used EU1000’s in my area go for $500 and up. So I decided to do it. I also purchased a bore measuring tool so I could check the old bore. I had a bore measuring tool years ago but I sold it.
So I finished the build, I did find the bore on the old cylinder was 0.002” over size at the piston pin axis at mid stroke. The piston skirt measurement was okay. I ran it gently through the first 10 hours, Honda's recommended first oil change interval, and ran it another 50 hours (my oil change interval) and had no oil usage whatsoever!
I have come to some conclusions from this experience: I have seen EU2000 specs. in the past that list the cylinder being cast iron (sleeve), but the 1000 does not list cylinder construction, and it did not appear to have a sleeve in it when when I had it torn down. I suspect the cylinder is aluminum with a “hard coating” as I am finding in my research. IMO, I don’t feel the EU1k cylinder would last as long as a EU2000. I do read about some EU2k’s with 5000 hrs! My EU1000 had over 1300 hrs (per hr meter) and that may be about it’s limit. If I were to rebuild one again, with high time, I would just replace the cylinder right off. It’s cheaper than buying a used EU1k, and now I basically have a new engine!