461 skirt on piston broke?

[K-techcowboy]

I've read it can over heat the saw if it's removed is that just somethin that would happen if I use the saw for hours on end.

If whats removed?

 

[Kilo1988]

If whats removed?

The "saddle" underneath the piston on the carb side of a 461. I was disassembling the saw and accidently broke the part of the saddle that mounts to the crankcase. Also I haven't had any luck finding the part online.

 

[rob066]

https://www.ebay.com/itm/224682706548?hash=item3450220674:g:KU0AAOSwTNRhq-oy

 

[rob066]

https://www.ebay.com/itm/1945021536...g73&norover=1&mkevt=1&mkrid=711-213727-13078-

 

[Kilo1988]

https://www.ebay.com/itm/1945021536...g73&norover=1&mkevt=1&mkrid=711-213727-13078-

Awesome thankyou

 

[bwalker]

My thoughts exactly. Yea alot of that is avoided by simply letting your saw warm up. I see it alot on motorcycles as I work on them for a living. Harleys are the worst. Especially after the cylinder becomes egg shaped. Some of the older hotrod Harley and s&s motors are so bad you can blip the throttle and here it knocking on heavens door. Customers always think its a rod but nope its just good ol fashion piston slap. Thats why I try to stress the importance of warming your engine up on anything before you go beaten er up. Especially when these sport bikes are revin to 17 18000rpm in the blink of an eye. He got lucky it didn't destroy the whole engine.

Warm up doesn't cause piston slap. It's most often caused by normal wear or from sucking dirt. In the latter case either manifests itself on the intake side. Given clearances and where the wrist pin is located a piston is always trying to rock in the bore. Open up these clearance from normal wear or dirt and it just gets worse until eventually you crack a piston skirt and lunch the motor.

 

[K-techcowboy]

The "saddle" underneath the piston on the carb side of a 461. I was disassembling the saw and accidently broke the part of the saddle that mounts to the crankcase. Also I haven't had any luck finding the part online.

Ah I see. Damn it that blows bro. I I dont have a 461 just an ol 460 or id try to assist.

 

[K-techcowboy]

Warm up doesn't cause piston slap. It's most often caused by normal wear or from sucking dirt. In the latter case either manifests itself on the intake side. Given clearances and where the wrist pin is located a piston is always trying to rock in the bore. Open up these clearance from normal wear or dirt and it just gets worse until eventually you crack a piston skirt and lunch the motor.

Very true and if thats a more contributing factor for a chainsaw that's good to know. I'm just too use to tearing down motorcycle, utv, atvs and watercraft with a slappy slap from improper warm up procedures because like you mentioned larger clearances cause piston slap and a cold motor the piston and rings haven't had time to expand to the correct clearances until normal operating temperature is reached. Its the same reason a proper compression test is done with a motor that is nice and warm vs dead cold unlike a leak down test which is done at room temp. I've literally seen high performance, fast high reving dirtbikes come back to the dealer with less then 2hrs on them because the genius that bought it wanted to go ride his CRF250 race bike like his old clapped out sluggish bullet proof Crf150 with nice horizontal lines on the short skirt piston and checks in the Nikasil in the cylinder with a complaint of a smacking sound for the first couple minutes of riding. Hurts me every time my service manager asks the customer how they warm there bike up. 95% of the time the first words out of there mouth are(what do you mean). I try not to hit the floor every time cause they just cost themselves about $1400 and no improper operation is not covered under warranty. The manufacturers have seen it enough to know better cause everything is documented in high detail. But it dose typically teach a life-long lesson sometimes not lol. There's only one thing on this planet I can't fix and I say this at lease once a week and that one thing is stupidity. Can I get an ame. Lol