562xp base gasket delete

[morbius18]

I picked up a 562xp with a piston pin bearing failure that destroyed the jug.

I'm replacing both crank bearings, both seals, new oem P&C. I'm planning on giving it a mild port job and copy some numbers from a big builder.

I plan on removing the base gasket and adjusting squish with a thinner gasket. I have no lathe, so no turning a popup or cutting the squish band.

Is there any spots to look for where I need to clearance the case? Specifically where the transfer covers hit, or the botttom of the jug skirt.

I've got the cases split, cleaned, and bearings removed. I have no problem grinding on it to give some room.

 

[SierraMtns]

Very cool. Post pictures as you go.

The 3 spots I hear that need to be clearance is the side transfer port cap screws, lower muffler holes and another spot inside the jug.

I think the spot inside the jug could be done with a piece of granite table top and stand paper taped to it. Or a piece of glass. You just want to take like 0.30 off so the jug sits down flat. Ill see if I can find the video that Walt posted about it.

 

[morbius18]

Very cool. Post pictures as you go.

The 3 spots I hear that need to be clearance is the side transfer port cap screws, lower muffler holes and another spot inside the jug.

I think the spot inside the jug could be done with a piece of granite table top and stand paper taped to it. Or a piece of glass. You just want to take like 0.30 off so the jug sits down flat. Ill see if I can find the video that Walt posted about it.

Thanks. I've been googling the crap out of it and find conflicting things like some run with no gasket just fine and some have to clearance. I'll use the dead cylinder to check the case halves and transfer covers.
You're talking about sanding the bottom of the jug insert that goes into the crankcase, correct?

 

[Andyshine77]

Thanks. I've been googling the crap out of it and find conflicting things like some run with no gasket just fine and some have to clearance. I'll use the dead cylinder to check the case halves and transfer covers.
You're talking about sanding the bottom of the jug insert that goes into the crankcase, correct?

Correct. If you're still going to use a thin gasket you may not need to clearanc anything. But these saws have tight clearances for sure.

 

[SierraMtns]

Thanks. I've been googling the crap out of it and find conflicting things like some run with no gasket just fine and some have to clearance. I'll use the dead cylinder to check the case halves and transfer covers.
You're talking about sanding the bottom of the jug insert that goes into the crankcase, correct?

Correct. If you're still going to use a thin gasket you may not need to clearanc anything. But these saws have tight clearances for sure.

Yes and yes....lol

 

[weimedog]

There are a few places you have to watch for clearance issues. First, the flange that projects into the cases only has a few thousands clearance WITH a base gasket. I have to trim them for clearance when I do my builds dropping the cylinder and adding a bit of compression with a popup. Second under the transfer caps as everyone will at high volume articulate. Another thing often over looked is what happens to the muffler mounting holes when you drop the cylinder....and I have to chuckle with some of the "built" ones have base gaskets fail under the muffler / transfer port area. They blame the 562 design and in fact whats happening if the cylinder is now lower and when you crank the muffler mounting bolt you actually jack that front of the cylinder up. SO have to watch that as well. Nothing a little die grinder can't fix. And not all will have an issue but many will. The tolerances are pretty tight on those saws. For most the best approach is to build them stock. They are a great running saw, if you want to mod them, focus on things like the muffler to get heat out and the covers. Some add heat shielding type materials to the "dam" between the cylinder and air box, I don't as the cover and muffler mods drop the heat on mine to the point I have never had an issue.

 

[SierraMtns]

Thanks. I've been googling the crap out of it and find conflicting things like some run with no gasket just fine and some have to clearance. I'll use the dead cylinder to check the case halves and transfer covers.
You're talking about sanding the bottom of the jug insert that goes into the crankcase, correct?

Have you decided yet to run a gasket or not? he he.

I know there is strong feelings on both sides. I was on the fence. Just wasn't sure how everything would seal up with different cooling rates with the different types of metals. SO...I jumped in with both feet. Built my 372 x-torq with no base gasket. Been running her hard for over the past year. Fallen a lot of trees with her. Still running good.

 

[SierraMtns]

There are a few places you have to watch for clearance issues. First, the flange that projects into the cases only has a few thousands clearance WITH a base gasket. I have to trim them for clearance when I do my builds dropping the cylinder and adding a bit of compression with a popup. Second under the transfer caps as everyone will at high volume articulate. Another thing often over looked is what happens to the muffler mounting holes when you drop the cylinder....and I have to chuckle with some of the "built" ones have base gaskets fail under the muffler / transfer port area. They blame the 562 design and in fact whats happening if the cylinder is now lower and when you crank the muffler mounting bolt you actually jack that front of the cylinder up. SO have to watch that as well. Nothing a little die grinder can't fix. And not all will have an issue but many will. The tolerances are pretty tight on those saws. For most the best approach is to build them stock. They are a great running saw, if you want to mod them, focus on things like the muffler to get heat out and the covers. Some add heat shielding type materials to the "dam" between the cylinder and air box, I don't as the cover and muffler mods drop the heat on mine to the point I have never had an issue.

No way its Mr Walt himself.

 

[morbius18]

There are a few places you have to watch for clearance issues. First, the flange that projects into the cases only has a few thousands clearance WITH a base gasket. I have to trim them for clearance when I do my builds dropping the cylinder and adding a bit of compression with a popup. Second under the transfer caps as everyone will at high volume articulate. Another thing often over looked is what happens to the muffler mounting holes when you drop the cylinder....and I have to chuckle with some of the "built" ones have base gaskets fail under the muffler / transfer port area. They blame the 562 design and in fact whats happening if the cylinder is now lower and when you crank the muffler mounting bolt you actually jack that front of the cylinder up. SO have to watch that as well. Nothing a little die grinder can't fix. And not all will have an issue but many will. The tolerances are pretty tight on those saws. For most the best approach is to build them stock. They are a great running saw, if you want to mod them, focus on things like the muffler to get heat out and the covers. Some add heat shielding type materials to the "dam" between the cylinder and air box, I don't as the cover and muffler mods drop the heat on mine to the point I have never had an issue.

Perfect, this was exactly what I was looking for. Thank you for taking the time to write that out.

 

[morbius18]

Have you decided yet to run a gasket or not? he he.

I know there is strong feelings on both sides. I was on the fence. Just wasn't sure how everything would seal up with different cooling rates with the different types of metals. SO...I jumped in with both feet. Built my 372 x-torq with no base gasket. Been running her hard for over the past year. Fallen a lot of trees with her. Still running good.

I will have to measure to see if I need one or a thinner. Still waiting on the new P&C.

My 346xp that I just finished only had about .012-.013 squish. I used an soda can gasket and ended up with .016". I'm not afraid to try.

 

[old guy]

Does anyone advance the ignition timing on these 562s ?

 

[cus_deluxe]

My (limited) understanding of the timingon these is that a little goes a long way.

 

[old guy]

I recently bought one, that had about .020 taken off the key, while I love the handling of the saw, the performance seems lacking, it seems to have a very rapid popping at high rpm.
I'm going to back that flywheel up and see if that changes.

 

[morbius18]

I drilled a few test holes in the bad cylinder to see the depth of the transfers where they could be smoothed. The raise over the muffler bolt hole is too thin to smooth out.

 

[morbius18]

I marked the case where it was hitting and ground on it a bit.

 

[morbius18]

Very cool. Post pictures as you go.

The 3 spots I hear that need to be clearance is the side transfer port cap screws, lower muffler holes and another spot inside the jug.

I think the spot inside the jug could be done with a piece of granite table top and stand paper taped to it. Or a piece of glass. You just want to take like 0.30 off so the jug sits down flat. Ill see if I can find the video that Walt posted about it.

I was curious with the bad jug and sanded a bit. Why specifically a piece of glass or granite. I know they are really flat, and for a cylinder base, I can understand. But the cylinder flange just has to not bottom out. As long as the lowest point is above the bottom of the crankcase flat part, it should be good. I did it on my cast Iron professional table saw. I haven't touched the new cylinder yet, but I did get it today.

 

[morbius18]

My less precise sanding method got the bad jug to sit flat. I might possibly have used a circular sander on the flamge bottom on this bad jug. I used this to test the clearance in the previous post, and didn't want to be sanding a bad one for an hour or so.

 

[SierraMtns]

I was curious with the bad jug and sanded a bit. Why specifically a piece of glass or granite. I know they are really flat, and for a cylinder base, I can understand. But the cylinder flange just has to not bottom out. As long as the lowest point is above the bottom of the crankcase flat part, it should be good. I did it on my cast Iron professional table saw. I haven't touched the new cylinder yet, but I did get it today.

Just a simple way to stand down the cylinder flange. There is many ways to skin a cat.

 

[SierraMtns]

Whats your plans on the intake?

 

[morbius18]

Whats your plans on the intake?

I don't really have any plans so far. I'm waiting for bearings to come in to my husky dealer. Then I'll degree it and draw the port shapes on the piston with a pencil.

The intake port looks to be a good size and shape to start with. Roughly holding the piston in thr cylinder and penciling the port does show I can go a tiny bit wider if I wanted. But it looks really nie to start off with.