Did I measure this squish correctly?

[paul hill]

I'm looking for someone to check my methods and math before I proceed.

Husky 357 with new aftermarket P & C.

Dab of grease with .031 electrical solder at 12,3,6, and 9 on piston.
New .020 base gasket.
Installed cylinder with gasket and moved piston to top of cylinder.
Removed cylinder and solder still measured .031 with tiny grease spots on the top of the cylinder.

Removed cylinder and re installed without the .020 base gasket this time.
Repeated above process.
Removed cylinder and the solder measured .018 and .019

Does this mean my squish was .038/.039 with the gasket and .018/.019 without the gasket??

It makes sense to me base on reading about it but I've never tried this before and want to have someone double check for me.

If this is right, is that an acceptable squish for this saw?

Lastly, how big of a bead of sealant do I use? I'm thinking maybe the diameter of a couple of toothpicks but not sure.

 

[CapitaineHaddoc]

Yes, it is acceptable. For a 60cc saw, it is ideal IMHO. You can run it without base gasket, but you have to use gasket paste. I use permatex ultra grey, but other brands are good too, Yamabond, Hondabond...

 

[Heilman181]

YES and YES!

You did it correctly and that is very good squish for a saw of that size. From what I have read .018-.020" is ideal for a 60cc saw.

Questions:

1.) How close to the piston edge did you have the solder pieces?

2.) What sealant are you going to use?

 

[old-cat]

The KEY to getting good measurement is the amount of force it takes to smash the lead and how close to the edge you get the lead. 6 o'clock and 3 o'clock are the only needed places.
I MUCH prefer Plastigauge, myself.

9 and 3 o'clock. Correction.

 

[Wagnerwerks]

You want to use a fuel rated sealant.... No offense, but ultra gray is not one of them. It is however my favorite flange sealant. Permatex has motoseal in their lineup for direct gas application. I use it, but it is a little runny.

 

[paul hill]

Thanks you all for the help and replies. Glad I measured right.

Heilman:
I put the solder right on the edge of the piston. I also checked it by using a long piece of solder stuck through the spark plug hole and up against the cylinder wall. I got the same readings on several pieces of solder doing it this way too.

The sealant I was planning on using is yamabond just because when I head into town, the Yamaha dealer is a lot closer.

Anybody have some suggestions on bead size?

 

[HuskStihl]

The only important nuber you measured is the squish without the base gasket. Adding the thickness of the uncompressed gasket to the gasketless squish measurement will not give you an accurate measurement of the squish with the gasket in place as it will compress quite a bit. It doesn't matter, as going gasketless is perfect in this situation. My vote is yamabond 4. I have yet to hear a negative comment about it, and it is formulated for this exact purpose. I put a thin layer on both surfaces, spreading it with my finger, trying to stay out of the inside of the case and cylinder. Then I try to put the cylinder straight down without too much movement and tighten in place.

 

[Heilman181]

Thanks you all for the help and replies. Glad I measured right.

Heilman:
I put the solder right on the edge of the piston. I also checked it by using a long piece of solder stuck through the spark plug hole and up against the cylinder wall. I got the same readings on several pieces of solder doing it this way too.

The sealant I was planning on using is yamabond just because when I head into town, the Yamaha dealer is a lot closer.

Anybody have some suggestions on bead size?

Sounds like you are good to go!

Keep us posted on the progress and your thoughts on the "adjustments" that you make.

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[redfin]

I agree with Wagnerwerks. Ultragrey is great for oil applications but not for gas. Also when you do place your cylinder down (with the bolts in) give it a little wiggle before you tighten.

This will "work" the sealant into any voids in the mating surfaces.

 

[RedFir Down]

Another thing you will notice is the impulse passage way on the intake side of the cylinder where it mates with the case... be sure not to block that with excess sealant.

6 o'clock and 3 o'clock are the only needed places.

I think you ment to say 9 o' clock and 3 o' clock right?

 

[old-cat]

Another thing you will notice is the impulse passage way on the intake side of the cylinder where it mates with the case... be sure not to block that with excess sealant.


I think you ment to say 9 o' clock and 3 o' clock right?

OOOPS!!

 

[RedFir Down]

No biggie... I just didnt want someone to read that later on and get confused.

 

[johnlhatfield1]

this is a good post-one i HAD been waiTing on. you put the 2 small pieces of solder on the piston at 3 and 9 using grease to keep it in place. measure the thicness of the solder after tightening the heAD BOLTS w/o a gasket. THIS tells you the squish. you want at leAST .018 I think. Im working on a stihl 460. Am I correct?

 

[Heilman181]

After checking my squish, I found a picture (posted by Mastermind, I think) where the solder was U-shaped with the open end towards the edge of the piston.

I like this idea better. It just seems safer than worrying about a small piece of solder falling down into the bottom end.

Sent from my SPH-D710 using Tapatalk

 

[Heilman181]

this is a good post-one i HAD been waiTing on. you put the 2 small pieces of solder on the piston at 3 and 9 using grease to keep it in place. measure the thicness of the solder after tightening the heAD BOLTS w/o a gasket. THIS tells you the squish. you want at leAST .018 I think. Im working on a stihl 460. Am I correct?

The 460 is considered a larger displacement saw, so you probably do NOT want the squish that tight. Most saws up to 60 cc are okay at .018-.020".

You should probably be in the .024" neighborhood.


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[paul hill]

Well, I got it done. The first attempt ended up not working because the intake boot got hung up on the body of the saw which ended in me getting Hondabond all over the place.

So, I took it apart again, cleaned up all the Hondabond and started over. Got it right the second time. Now I'm putting the rest of the saw back together.

Tomorrow I'm going to try a vaccum/pressure test and start on a first attempt at a muffler mod. I'll probably throw the muffler on before opening it up just to see if i can get the saw started.

I'll let you know how it turns out.

 

[Jeff Lary]

you are doing everything right. I was going to suggest that you let it set up overnight but I see you are doing that. Good luck Jeff

 

[Heilman181]

Well, I got it done. The first attempt ended up not working because the intake boot got hung up on the body of the saw which ended in me getting Hondabond all over the place.

So, I took it apart again, cleaned up all the Hondabond and started over. Got it right the second time. Now I'm putting the rest of the saw back together.

Tomorrow I'm going to try a vaccum/pressure test and start on a first attempt at a muffler mod. I'll probably throw the muffler on before opening it up just to see if i can get the saw started.

I'll let you know how it turns out.

What Hondabond did you end up using?

Hondabond 4, 5, HT, etc....?

 

[dozerdan]

I use real gaskets not gasket in a tube. If I have to disassemble a saw that has sealer on the base I charge an extra 25.00. That pays me for my time to clean that crap off that shouldn't be there to start with and machine the base.

Later
Dan

 

[Heilman181]

I use real gaskets not gasket in a tube. If I have to disassemble a saw that has sealer on the base I charge an extra 25.00. That pays me for my time to clean that crap off that shouldn't be there to start with and machine the base.

Later
Dan

So do you machine the base an extra .020" and use a gasket instead of just removing the gasket?

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