462 acting weird.

[TX_Welder]

My 462 went wonky on me yesterday. Doing some storm cleanup from Nicholas, downed one tree, cut up two more. Towards the end of the last tree it would idle high after a cut and bog when you pull the trigger or die altogether. Sometimes it would hiccup in the cut then back to wide open. Shut it off and dad finished everything off with his 441.

It did this a while back and had me wondering if I'd found the limits of what the mtronic could handle with my muffler and air box mods.
The muffler mod was a bark box knock off I fabbed up. Outlet in the cover was 3/4" x 1" with screen welded over it. Stock outlet was still open also. The air box mod is a WCS foam filter with the top cover cut out to expose the filter. Base gasket is removed as well.

When I had the issue a wile back I put the stock cover back on the muffler (which is also modded but not as extreme) and after a cut or two it lined out and was fine until yesterday.

When I first had this issue I vacuum tested it and it passed with flying colors. I haven't done a reset on it yet but I don't think it's going to help it. I'm at a loss. Carb solenoid maybe ?

 

[Woodslasher]

Stupid question, what's the fuel level like? I've had a few times where I thought my saw was going screwy, but it was just running out of fuel.

 

[TX_Welder]

1/2 tank. That's what I thought at first. That's exactly what was happening, like it was leaning out running out of fuel.

 

[andyshine77]

I may be jumping the gun, but that really really sounds like an air leak, and you said the base gasket was removed. Maybe have your dealer hook it up and see if any codes pop up. After that vac/pressure test, maybe the base is leaking you never know.

 

[sawmikaze]

The coil on my first 462 I bought got stuck in sone kind of rich mode and nothing I could do changed it. I think it had 28 hours on it if I remember correctly. It was a warranty thing so no big deal.

Try the solenoid.

 

[TX_Welder]

The coil on my first 462 I bought got stuck in sone kind of rich mode and nothing I could do changed it. I think it had 28 hours on it if I remember correctly. It was a warranty thing so no big deal.

Try the solenoid.

It is fat on the low end for sure.

 

[TX_Welder]

I may be jumping the gun, but that really really sounds like an air leak, and you said the base gasket was removed. Maybe have your dealer hook it up and see if any codes pop up. After that vac/pressure test, maybe the base is leaking you never know.

Air leak has been on my mind because I removed the gasket. But, I checked it once already and it was good. Going to check again to be sure.

 

[Mastermind]

Air leak has been on my mind because I removed the gasket. But, I checked it once already and it was good. Going to check again to be sure.

Did you check squish?

 

[TX_Welder]

Did you check squish?

Not lately. When I pulled the gasket it was .019-.020. Clearance before delete was .034, gasket measured .015

I'm thinking about making mandrel and cutting the base on my lathe so I can keep that squish and run a gasket. I prefer gaskets.

Although, I use silicone in other engine assemblies and never have leaks. I used dirko for sealant on this one.

 

[Mastermind]

Not lately. When I pulled the gasket it was .019-.020. Clearance before delete was .034, gasket measured .015

I'm thinking about making mandrel and cutting the base on my lathe so I can keep that squish and run a gasket. I prefer gaskets.

Although, I use silicone in other engine assemblies and never have leaks. I used dirko for sealant on this one.

I'd be willing to bet you have much less clearance than you think. How thick was the solder you checked it with?

 

[sawmikaze]

Not lately. When I pulled the gasket it was .019-.020. Clearance before delete was .034, gasket measured .015

I'm thinking about making mandrel and cutting the base on my lathe so I can keep that squish and run a gasket. I prefer gaskets.

Although, I use silicone in other engine assemblies and never have leaks. I used dirko for sealant on this one.

Maybe this matters and maybe it doesn't...

I think I made a similar mistake when I measured the squish on my 462, I thought I had .031 thousies...but it was actually .025...

I know not all jugs are the same but I don't think you have enough room to delete the gasket...

 

[Stump Shot]

Maybe this matters and maybe it doesn't...

I think I made a similar mistake when I measured the squish on my 462, I thought I had .031 thousies...but it was actually .025...

I know not all jugs are the same but I don't think you have enough room to delete the gasket...

+1 on the assessment.

 

[andyshine77]

Measuring squish you definitely want to use the smallest rosin core you can get by with, and I always have the starter attached and pull it over fast, just rolling it over is not good enough IMHO, take the reading at the very edged of the solder.

 

[TX_Welder]

I've got to hunt down some smaller solder, all I've got left is .062"
Believe I used to have some .035 but I burned it all up wiring lights on my ranger.

How much vacuum is usually pulled to test a saw ? Got 15in on it now, been holding about ten minutes. All I have is a mighty vac but I may be able to scrounge something up to put some pressure in it. I'll have to look and see what I can find.

I know everybody has a different squish number they are comfortable with but what is the bare minimum anyone has ever seen run reliably ?

 

[Stump Shot]

I've got to hunt down some smaller solder, all I've got left is .062"
Believe I used to have some .035 but I burned it all up wiring lights on my ranger.

How much vacuum is usually pulled to test a saw ? Got 15in on it now, been holding about ten minutes. All I have is a mighty vac but I may be able to scrounge something up to put some pressure in it. I'll have to look and see what I can find.

I know everybody has a different squish number they are comfortable with but what is the bare minimum anyone has ever seen run reliably ?

7 inches of mercury or .5 bar is standard held for a minute. 7 PSI or .5 bar for pressure.

 

[andyshine77]

I've got to hunt down some smaller solder, all I've got left is .062"
Believe I used to have some .035 but I burned it all up wiring lights on my ranger.

How much vacuum is usually pulled to test a saw ? Got 15in on it now, been holding about ten minutes. All I have is a mighty vac but I may be able to scrounge something up to put some pressure in it. I'll have to look and see what I can find.

I know everybody has a different squish number they are comfortable with but what is the bare minimum anyone has ever seen run reliably ?

Depends on the saw and displacement, for a saw that size you really wouldn't want less than .020" though I have see saws that size run fine with .017" though I don't recommend that. .062" will have a hard time compressing, these guys just may have found your problem.

 

[TX_Welder]

7 inches of mercury or .5 bar is standard held for a minute. 7 PSI or .5 bar for pressure.

We're good then. Been holding 15 inches for almost an hour. Couldn't get enough pieces together to put positive pressure to it. Who makes a tool that will do both pressure and vacuum other than the west coast muscle saws guy ?

Found some solder and checked squish again and @Mastermind was right, didn't have as much as I thought. Squish is .0145 according to my mitutoyo's.

 

[jacob j.]

If I'm using larger solder for a squish test, I take a box knife blade and cut it in half.

Who makes a tool that will do both pressure and vacuum other than the west coast muscle saws guy ?

I use a Mityvac 8500. I got a used kit off Ebay for $55 delivered.

 

[TX_Welder]

Okay so it seems at .0145-.015, depending on how I hold my mouth when measuring, my squish may be a ch on the tight side. Probably gets a little tighter at wot and as things warm up also.

Will that cause something like a dieseling effect making it idle high? Why would it bog when you stab the throttle? Shuts off fine with the switch.

I'm here to learn, educate me.

 

[huskihl]

If you’ve been running it and there’s no ring around the outside of the band or crown of the piston, it’s probably alright as long as you don’t let carbon build up