A little bit of STRAIGHT GAS!!

[isaaccarlson]

it looks like it dragged a bunch of aluminum around that bearing....

HMMMMMM....is there any metal missing from anywhere? Did a chunk of the rod break off in the bearing?

 

[isaaccarlson]

maybe one of the bearing rollers went to pieces and tore up the rod end....

gonna haf ta take it apart the rest of the way to find out....

 

[WoodChuck'r]

ha ha ha. You never heard that saying before!! LOL!

Nope!

That was definitely a new one for me!!

 

[parrisw]

HMMMMMM....is there any metal missing from anywhere? Did a chunk of the rod break off in the bearing?

Didn't see anything.

gonna haf ta take it apart the rest of the way to find out....

The crank doesn't really come apart.

 

[isaaccarlson]

dremel.....and a cutoff wheel....a reinforced one.

Pics!!!!! we gotta know what happened...

 

[parrisw]

Nope!

That was definitely a new one for me!!

ha ha. Now you can go tell all your friends!! LOL

 

[parrisw]

Pics!!!!! we gotta know what happened...

ha ha, not gona happen. even if I get it apart?? Its not going to tell me anything, besides what I already know.

 

[tree monkey]

straight gas or too little oil in the gas will score the piston. no if and or but about it. the bearing broke. simple as that.

if the bearing lacked lube the end of the rod would be discolered. blueish.

this is a comon failure for newer huskys. 371/2

i've been a saw tech for 30 years. i hope i've learned something in that time. lol

 

[parrisw]

straight gas or too little oil in the gas will score the piston. no if and or but about it. the bearing broke. simple as that.

if the bearing lacked lube the end of the rod would be discolered. blueish.

this is a comon failure for newer huskys. 371/2

i've been a saw tech for 30 years. i hope i've learned something in that time. lol

Yes, I've seen that happen too. And yes it was blue end of the rod. What do ya think of the gas though? Doesn't look right to me.

 

[tree monkey]

put some known straight gas in a bottle and compaire.

it's cheap off brand oil.

30w oil turns gas brown.cheap oil with little to no dye will do the same.

 

[Jacob J.]

thats not a lack of oil failure. there is no sine of heat on the rod/

how mutch time is on the crank?

The saw has been outa my hands for over a year now in a commercial application?? So its anybody's guess on how much time.

If its not lack of lube then what??? What say you about the gas??? I think you need to look at it again. I'm not yankin anybody's chain here. That aint proper mixed gas in there, I don't care what anybody says.

I've seen that happen with OEM cranks when operators run straight gas by mistake. I have two OEM 372 cranks in my scrap box that came out of straight-gassed saws that look identical to the crank in the picture. Neither have bluing on the rods and the pistons and cylinders were just fine.

 

[parrisw]

I've seen that happen with OEM cranks when operators run straight gas by mistake. I have two OEM 372 cranks in my scrap box that came out of straight-gassed saws that look identical to the crank in the picture. Neither have bluing on the rods and the pistons and cylinders were just fine.

opcorn:

 

[parrisw]

put some known straight gas in a bottle and compaire.

it's cheap off brand oil.

30w oil turns gas brown.cheap oil with little to no dye will do the same.

I still think there was just a little mixed gas in the tank, then he filled with straight gas.

I don't need to compare that gas to known good gas, I know what good gas looks like. i've been a auto mechanic for 15 years. i hope i've learned something in that time. lol

 

[tree monkey]

also

not all cheap oil is bad.
poor oil tends to coat the crank, case and piston skirt with black crap. old gas will too.
i myself would not blame the oil in this case.

 

[parrisw]

also

not all cheap oil is bad.
poor oil tends to coat the crank, case and piston skirt with black crap. old gas will too.
i myself would not blame the oil in this case.

I don't run cheap oil period!!!!!!!! Just not worth it. There was oil in the saw, and it is very dark looking.

 

[mtngun]

I've seen that happen with OEM cranks when operators run straight gas by mistake. I have two OEM 372 cranks in my scrap box that came out of straight-gassed saws that look identical to the crank in the picture. Neither have bluing on the rods and the pistons and cylinders were just fine.

Interesting. I never would have guessed.

 

[Jacob J.]

Interesting. I never would have guessed.

There's a lot of things that can happen when a two-cycle engine has insufficient lubrication. Naturally, the first thing that comes to mind is a scored piston and cylinder, but this isn't always the case (which doesn't stop knee-jerk reactionaries who've been inside a couple saws to scream "That ain't it!").

A logger friend of mine ran almost a full tank of straight gas through his 262 once on a landing by mistake. There was no discernible damage and the saw ran fine for another year. I was a witness to both the gas in the can the remaining gas in the tank to confirm it was straight gas. There may have been a small amount of mixed gas left in the tank when he filled up but it was negligible.

We've run brand new saws at Stihl technical update meetings on raw gas to failure a number of times, with a number of different results.

 

[parrisw]

There's a lot of things that can happen when a two-cycle engine has insufficient lubrication. Naturally, the first thing that comes to mind is a scored piston and cylinder, but this isn't always the case (which doesn't stop knee-jerk reactionaries who've been inside a couple saws to scream "That ain't it!").

A logger friend of mine ran almost a full tank of straight gas through his 262 once on a landing by mistake. There was no discernible damage and the saw ran fine for another year. I was a witness to both the gas in the can the remaining gas in the tank to confirm it was straight gas. There may have been a small amount of mixed gas left in the tank when he filled up but it was negligible.

We've run brand new saws at Stihl technical update meetings on raw gas to failure a number of times, with a number of different results.

Thanks JJ.

Lots of finger pointing here not many answers. In my years of being an auto mechanic, you must keep an open mind, closed mindedness never helps. I've seen many things which goes against the grain of normal thinking.

I still stand by what I orignally thought.

Here is a pic of a OEM 371 crank that failed with mixed gas.

 

[Jacob J.]

Here is a pic of a OEM 371 crank that failed with mixed gas.

The two cranks I have look identical to that. One is actually a 365 crank- the saw was put back into service with a new crank and the same cylinder and piston.

The other was a 372 crank and the skirts and sides of the piston were fine, there was a small amount of spalling on the crown which ended up being pieces of the big end rod bearing cage.

 

[parrisw]

The two cranks I have look identical to that. One is actually a 365 crank- the saw was put back into service with a new crank and the same cylinder and piston.

The other was a 372 crank and the skirts and sides of the piston were fine, there was a small amount of spalling on the crown which ended up being pieces of the big end rod bearing cage.

I noticed some very small marks on the edge of the piston crown.