Hi all, I haven't posted here before but I have done a lot of reading. My 395xp quit oiling during a milling session. Upon inspection I discovered a stripped plastic gear for the oil pump that is driven by the clutch drum. This may have originated due to use of veggie oil and improper storage, I replaced the whole oil pump assembly, and also got a new clutch assembly, with bearing. At first I thought it was fixed, lots of oil on the bar, proceeded to tune the carb. A day or so later I re-visited the carb tuning with a handy engine RPM app on the smart phone. No issues. At one point, I did notice the chain turning at idle and idle adjust and low jet would not solve that. Another start later and that issue went away? The oil probably stopped then to. I did blow out the oil holes to the bar and tank when I had the pump out. The only washer is between the crank seal and the plastic gear. The wear pattern on the failed parts looks like the center of the threaded part of the plastic gear meshes with the piston pinion of the oil pump, looks like they line up correctly. Decided to work over a couple new ripping chains, and I discovered that the chain would not turn freely, the crank shaft was turning with the clutch drum due to an interference fit of the new plastic pump drive gear. I don't think I ordered the wrong part, I bought a set of 4, likely not OEM. Some research here and around the web. I sanded the bore of another plastic gear so that it was a slip fit on the crank shaft. Ran the saw on a couple slabbing cuts, and noticed no oil again. Opened it up and had another stripped gear. 1. stripped gear - original had worked, unsure why it failed maybe oil blockage. 2. stripped gear - new one was a tight fit on the crank shaft. 3 stripped gear - Modified a new one to slip easily on crank shaft. I have two more new gears and don't want to repeat this insanity. I haven't checked for play in the crank shaft itself yet, will do so today. The seal looks good and I haven't noticed any play when working with the oil pump and clutch. I haven't had the other side apart. Any advice is appreciated. I plan to check closer that all the parts are right. a couple quick questions? 1. Is the clutch drum supposed to have end play, how much is normal? It can move side to side a little bit, The clutch comes up tight to the bearing but I can still move the drum in and out, Similar to how the sprocket can move side to side on the drum splines. This creates some bell ringing. If this is not correct, I can see how the plastic gear might be able to move out and strip. - I can see how if the bearing was too long, that this might be the case, I will compare later today with original clutch parts and bearing. - maybe I need a another washer in there? - the normal rotational direction should work to suck the plastic gear in toward the case. - I put some grease in there on the gears. 2. I read somewhere that someone else sanded out the bore of the plastic gear like I proceeded to do. Is this normal, did I get a bad batch of gears? - doing this did allow the chain to move freely without turning over the crank. - are there any other modifications to the gear or parts that will help it along. 3. Is there a proper break in procedure for a new oil pump or pump gear. Hopefully a simple issue, a little long winded but maybe that will help narrow it down.