Well I got a full diagnosis on the 3400 today and there where signs of what I would find. First Let me preface by stating that I purchased this saw from a very old gentleman that stated it was a good saw that had sat for a long time. The first sign was the muffler. I always clean out the carbon from the exhaust port when I buy an old saw. The screen was caked up with nasty gummy old gas. Second was the crank case was pretty nasty when I removed the cylinder. Third was the low compression. After installing the nos piston and caber rings it ran. Horribly but it ran. I let it go for a minute and decided this just aint right. Then it dawned on me. Its sucking bar oil into the combustion chamber. The old man was using used motor oil on top of it. The new piston is not new anymore. The skirt has a ding in it and the caber rings are now in the trash. Im going to try and salvage the piston and use the oem rings that came with it. The case has been split and cleaned.(it was gross). The seals where new but I don't like trying to reuse them. The bearings are out and I'll have to replace.
So a couple take aways. I don't consider myself a novice at this point as I have a few hundred saws under my belt now but feel like I should have caught this sooner. That severely gummed up spark arrestor will be a sign to split the case in the future. And trust your instincts, dont assume compression is going to go up enough in this type of scenario to fix itself. I've gone down a rabbit hole on this one spending way more money than I should but I just like this model and will not sell it.
Couple questions.
1. What are the Numbers for the crank bearings? My eyes are bad and can't make out the numbers.
2. Was there supposed to be a case gasket? It was just siliconed together.
So a couple take aways. I don't consider myself a novice at this point as I have a few hundred saws under my belt now but feel like I should have caught this sooner. That severely gummed up spark arrestor will be a sign to split the case in the future. And trust your instincts, dont assume compression is going to go up enough in this type of scenario to fix itself. I've gone down a rabbit hole on this one spending way more money than I should but I just like this model and will not sell it.
Couple questions.
1. What are the Numbers for the crank bearings? My eyes are bad and can't make out the numbers.
2. Was there supposed to be a case gasket? It was just siliconed together.