AM 660 question ??

[Stihlsmoking]

Well I was asked to look at a saw by a tenant. As soon as I seen it noticed it had no serial # showed him on fleabay how cheap they were. So told him I'd look at it but had no hopes for it. Found piston scorched didn't trouble shoot as to cause?
Question has anyone put a different AM top end on one of these cheap engines?
Or has this been covered here ?
They don't use saw often but when they do it has a 48" bar and they cut a 4'x4' stack of 2x4's on a pallet. I recommended a ported saw from one of the builders here ? And running 40:1 or 32:1 for this kind of cutting.
Thought about the MM 660 kit from HL but do you think the Chinese bottom end would hold up ? Also has anyone replaced seals on a AM crank ?
Thanks. Here is the carnage

 

[jacob j.]

Have you been able to do a pressure/vacuum test on the short block yet? I had one of those new that failed pressure and vacuum out of the box and culprit was a poorly installed flywheel side seal. I guess they're not paying the Malaysian schoolchildren that put these together what they used to.

 

[Definitive Dave]

Oem replacement cases have no serial number either.
Treat it like an oem case and do the same tests and treatments

 

[Mark71gtx]

I say pressure and vac test it. Fix the leak if there is one. Replace the top end. Test it again. Tune it. Put it back to work. The local tree service has a 660 with an aftermarket crank that is still going strong after over a year of abuse.

 

[trooney]

What he said!! ^^^^^

 

[Stihlsmoking]

Have you been able to do a pressure/vacuum test on the short block yet? I had one of those new that failed pressure and vacuum out of the box and culprit was a poorly installed flywheel side seal. I guess they're not paying the Malaysian schoolchildren that put these together what they used to.

I didn't do press/vac test as I wasn't sure if this would hold up for what they are using it for ? Or if oiler would keep up ?
I'll try press/vac test and see where they what to go from there?
Thanks

 

[Mark71gtx]

Shoot, if they don't want it send it here...

 

[MustangMike]

There is a whole thread about them on the AS site. Biggest complaint seems to be the bar adjuster, and sometimes missing parts.

How do you know this saw was not just straight gassed? No saw will hold up to that!

I don't think they are built as tough as OEM, but the running ones seem to be holding up OK.

 

[Stihlsmoking]

Well I'm doing press/vac test found decomposed button leaking.
Plugged that! Saw still leaking checked both seals not leaking ?
Checked screw on intake boot tighten about 20 turns still leaking?
Gotta be impulse, intake boot, around jug, unless case is leaking?
Taking a break.

 

[Mark71gtx]

I bet the intake boot is torn - especially if you tightened it 20 turns... I assume you meant 2 turns. I have had mystery leaks like that before. The best way to find the problem is to put pressure on it and keep spraying soapy water on it until you find the bubbles. Sometimes they leak at the cylinder base.

 

[Stihlsmoking]

I bet the intake boot is torn - especially if you tightened it 20 turns... I assume you meant 2 turns. I have had mystery leaks like that before. The best way to find the problem is to put pressure on it and keep spraying soapy water on it until you find the bubbles. Sometimes they leak at the cylinder base.

No I meant 20 like 10 full turns kept spraying no bubbles gonna look more later I think it may be boot also. I think that was a used oem boot ?

 

[Mark71gtx]

With that many turns I would just about guarantee the bottom of that boot is torn. I have seen that a few times.

 

[jmssaws]

It shouldn't score it if the clamp was loose
Most I take apart the clamp is loose on.

Dull chain and a crappy tune will kill way more than a airleak.

 

[Mattyo]

dunk it in water if you can't find the leak....

372xp, but same idea

 

[Stihlsmoking]

dunk it in water if you can't find the leak....

About to dunk it in the Ohio river. lol but too many good parts on it. Lol

 

[Mattyo]

I get frustrated too....gotta have an ego about it...ya can't let it beat ya

 

[dall]

I get frustrated too....gotta have an ego about it...ya can't let it beat ya

you can beat it


with a hammer

 

[MustangMike]

My trick to finding hard to find air leaks (don't use too much pressure), but if you hook a bicycle pump to it (instead of the vac/pressure tool) you can really increase the volume, and often that will help you find the leak. You can often either hear it, or feel it. It is hard to find big leaks with the vac/pressure tool, volume is just too low.

 

[jmssaws]

I use a paint gun regulator and a bucket of water for the hard to find ones

90% of the time it's the flywheel side seal that's been installed wrong.