This is Turtle.
Well I read all the reply this even1) He seemed to see very few MS-310 -- 4.0 H.P. come back for any repairs at all but seen a larger number of MS-361 or C -- 4.3 H.P. or MS-390 -- 4.3 H.P. or bigger and then up to the MS-660 at 7 H.P. or bigger before he starts to see no trouble.
2) He said if he was cutting trees for a living he would go ahead get the MS-390 because of the .3 H.P. more but if you was cutting about a tree a month stick with the MS-310 for you don't need the speedy cut to make a living and he just does not see many of them come back for repairs at all.3) He said he seems to think that when you break the 4.0 H.P. level on the engines it may put a strain on the engines or something like that. He then said if you break the 4 H.P. level you have to go to the MS-660 -- 7 H.P. level to not see them come back for repairs. He said this 4 to 7 H.P. engines seem to have all the trouble with very little below 4 h.p. and 7 h.p. and up. He also added the Huskey had the same problem that he seen the same thing as trouble verses the 4 h.p. to 7 h.p. engines. Outside this range he sees very little repair troubles.
4) He did not recommend any Bar lengths over the 18" on the MS-310 or the MS-390 because of loads to the engine and cutting ability. The 18'' bar was all the teeth per wood surface you would want as to not lug the engine down. The 20"+ bars started to load up the engines and cause the engine to lug down when loaded up cutting. The Bar length does play a part in the longivity of the engine and having trouble or engine malfuctions.5) He said the 18" Bar would not jam in the 36" tree [ end cutting but 20" would ] and I could cut both sides and what was left in the middle would snap off. It did just what he said. To get the longer bar i would need the MS-660 and could cut up to with a 36" bar and still have the horse power to not jam.
6) The worst thing to do to a saw is to just use it every once in a while and put it up for long periods of time and if i could , use it as much as possible. The oil from the gas will keep the bearing and parts oiled up and setting it up let the oil drain off of the cracks and holes where you need the oil to be worked down into. Running it keeps the oil worked down into the place where you really need it.After sizing up everything that was said here and there. I ended up with a MS-310 with a 18" Bar and come home and started butchering that tree. It took about two hours and 5 tanks of gas and oil and it Got-R-Done. I think i got the right size of saw for cutting something like this but time will tell for duriability. I wished I could look out 2 or 3 years from now and see about this saw, but i will have to wait and see.
I would like to say thank you to all the hands that spoke here and helped out on this project. Thank You Thank You Thank You.
TURTLE