Ms 462 repair on a budget

[Bob Hedgecutter]

I apologize, didn't mean to insult you.

No need for apology- not insulted in the least.
Just pointing out I was aware of the threaded "Helicoil" repair and my personal choice /advice to avoid the spring method of repair option. Lots of people that deal in low end consumer equipment that was never designed for repair will use and swear by the spring repairs because they deal in low grade stuff that never makes it back to them, or is never used more than a handful of hours a season.
You are talking about repairs to a high value modern piece of professional grade equipment- it deserves to be repaired correctly or have parts replaced with same.

 

[numnutz6383]

No need for apology- not insulted in the least.
Just pointing out I was aware of the threaded "Helicoil" repair and my personal choice /advice to avoid the spring method of repair option. Lots of people that deal in low end consumer equipment that was never designed for repair will use and swear by the spring repairs because they deal in low grade stuff that never makes it back to them, or is never used more than a handful of hours a season.
You are talking about repairs to a high value modern piece of professional grade equipment- it deserves to be repaired correctly or have parts replaced with same.

What's your choice of thread sealant when using the Sav-a-Thread? Red loctite or something more high temp?

 

[Bob Hedgecutter]

What's your choice of thread sealant when using the Sav-a-Thread? Red loctite or something more high temp?

I dont use threaded repairs that need sealant- I have a phone a friend option that has the gear for the bottom expanding timeserts.

 

[numnutz6383]

I dont use threaded repairs that need sealant- I have a phone a friend option that has the gear for the bottom expanding timeserts.

Just making sure I'm not misunderstanding, time-sert bottom expanding inserts do not require sealant, but sav-a-thread swaged from the top inserts do require sealants. Am I off?

 

[Bob Hedgecutter]

Just making sure I'm not misunderstanding, time-sert bottom expanding inserts do not require sealant, but sav-a-thread swaged from the top inserts do require sealants. Am I off?

To be honest- without checking the speck- I could not tell you what is recommended.
The ones I have access to are fitted from the top with an oversized collar and then an expanding plug is threaded through to expand the bottom section of the insert into stepped threads to hole the insert both at the top and the bottom of the repair- so do not need liquid sealant- its all mechanical and cannot work loose.
Any other options- check their specs and see what the manufacturers recommend.

 

[ZeroJunk]

Helicoil is a brand name. The thread repair kit is not a coil.

 

[chipper1]

Are Lil Red Barn pistons a waste of money?

After the way they treated me yrs ago, I do everything I can to turn people away from them.

It’s got nothing to do with quantity of oil. If anything, it looks exactly like it was run on Ultra at 50:1, given how dry the can is

Ultra FTW , I hate that stuff , about as much as front tensioners lol.

 

[huskihl]

So, you are thinking that excess oil will not blacken a piston. Curious logic.

Excess good oil won’t. It’s the lack of detergent and flashing off at too low of temperature that does that. Or blow by. Or a restricted muffler outlet

 

[L34]

Try a key or keen sert

 

[Chevboy0167]

I'm gonna try this stuff on an insert if I ever need to. Fuse that baby to the cylinder! LOL

https://www.vibra-tite.com/threadlo...t-lock-extreme-high-temperature-threadlocker/

 

[numnutz6383]

Excess good oil won’t. It’s the lack of detergent and flashing off at too low of temperature that does that. Or blow by. Or a restricted muffler outlet

Can you explain to me "blow by"?
What would cause flashing off at too low of a temperature? Too much compression? Wrong plug heat range?

 

[angelo c]

Can you explain to me "blow by"?
What would cause flashing off at too low of a temperature? Too much compression? Wrong plug heat range?

Compression getting past rings( worn or compromised). Spark timing or weak spark might cause pre-post ignition? Sometimes worn piston skirts can affect ring seal as well.
Lots of curbs to bump into before you get to the "mixture" off ramp.
What did the exhaust port look like compared to the cyl ?

 

[Mad Professor]

Much of the problem with helicoil repairs is the installer. Or the hole is too far gone. I've used them on 4-cyl bike motors, where you had to do the repair in situ, that is to take the head off you had to remove the motor. Didn't have any problems.

If you don't take the head off, put grease on the tap to catch the cuttings.

That said a better insert is a better repair.

The helicoil plug repair kits work fine. I haven't had one come back.

 

[ZeroJunk]

Whatever kit you choose if the saw has good compression I would not take it apart. I don't see anything wrong with the piston other than stain, maybe a couple of tiny scrapes from carbon, but that may only be in the stain..
It doesn't have a lot of hours on it. The early models failed because with skirt wear they would hang the deflector or whatever you call it and wreck the saw.

 

[numnutz6383]

Whatever kit you choose if the saw has good compression I would not take it apart. I don't see anything wrong with the piston other than stain, maybe a couple of tiny scrapes from carbon, but that may only be in the stain..
It doesn't have a lot of hours on it. The early models failed because with skirt wear they would hang the deflector or whatever you call it and wreck the saw.

Ok then, I'll give it a good cleaning, retap it with the helicoil insert and test compression first. What kind of compression should I expect? What is the cutoff pressure to just throw the towel in?

 

[angelo c]

Ok then, I'll give it a good cleaning, retap it with the helicoil insert and test compression first. What kind of compression should I expect? What is the cutoff pressure to just throw the towel in?

Depends on what dial you're using for compression testing...Lotta variables involved. But something above 125 will run. 135 will run well...and 145 should be just fine

 

[ZeroJunk]

Yeah, I don't find compression testers to be accurate at all on small displacement .
You'll know when you pull it with the decomp out.

 

[sean donato]

Get a good gauge, I have several compression testers and none of them read any bit different on a small displacement engine vs a larger engine.

 

[sean donato]

If your not welding those threads up, you'll want an insert that's swedged into place. Loctite breaks down with heat. Even the "high temp" stuff softens over time. Timeserts work great, lock n stich full torque are the best, but cost about 4x what the time serts do. You get what you pay for with thread inserts.

 

[ZeroJunk]

Get a good gauge, I have several compression testers and none of them read any bit different on a small displacement engine vs a larger engine.

LOL. The one we got from Stihl doesn't read anything, as in zero. Bad valve I'm sure.

Anyway, If you need a gauge you need to work on more saws.