High Quality Chainsaw Bars Husqvarna Toys

Cross Performance 660 top end failure

Brewz

Free Range Human in a Tax Farm
Local time
10:49 AM
User ID
550
Joined
Jan 16, 2016
Messages
4,217
Reaction score
14,297
Location
Hunter Valley - Australia
Country flag
Hi Folks.
I noticed one of the boys doing the Chinese 660 clone saws had an issue with a hung ring on one of these top end kits.

I have had one here for a little while now and put it on a saw I rebuilt for a friend.
It started fine at first, let it warm up, tuned the idle and rough adjusted the carb to be 4 stroking strong and shut it down to be field tuned and tested in some timber.

I got it out in the field and tried to start it, it popped 2nd pull but the pop was very short.
flicked it up to run position and cranked it over a few times and nothing, wouldn't start.
Went to try it without the decomp but found the decomp was already closed.
The saw suddenly had no compression.
Took it home and checked the decomp and spark plugs, both fine.
Took the muffler off and it was full of metal.
It has hung the ring on the exhaust floor and destroyed the piston and cylinder.

Not happy!

It was completely stock, as the kit came out of the box, with gasket installed.
Wasn't cheap with post and exchange to Australia either.

I am wondering if anyone else has experienced one of these failures?

IMG_2247.JPG
IMG_2248.JPG

IMG_2249.JPG
IMG_2250.JPG
IMG_2252.JPG
 

Canadian farm boy

“Normal” people scare me.
GoldMember
Local time
7:49 PM
User ID
309
Joined
Dec 29, 2015
Messages
7,806
Reaction score
49,228
Location
Ontario, Canada
Country flag
Doesn't look much of any bevel on the exhaust port. From the look of things I'd guess it hung a ring on the down stroke.
Chitty deal brews.
I haven't played with one of the cross performance cylinder kits yet. Yours is the second one I know of now that has hung a ring.
 

T.Roller

Mastermind Approved!
Local time
7:49 PM
User ID
1277
Joined
May 11, 2016
Messages
15,385
Reaction score
53,444
Location
Southeast, TN
Doesn't look much of any bevel on the exhaust port. From the look of things I'd guess it hung a ring on the down stroke.
Chitty deal brews.
I haven't played with one of the cross performance cylinder kits yet. Yours is the second one I know of now that has hung a ring.
I beveled mine before I put it on my buildoff saw. The factory bevels were very poor
 

Chainsaw Jim

Con Artist LLC
Local time
4:49 PM
User ID
836
Joined
Feb 8, 2016
Messages
4,014
Reaction score
77
Location
Springfield Oregon
I'm thinking bad rings.
Those soft, rounded edges provide enough surface area to grab an edge. OEM rings would have likely not hung up with a sharper, more square edge to keep the ring flexing tighter to the piston.
I've seen too many ports with absolutely no chamfering run with no problem to blame this solely on that.
 
Last edited:

BuckthornBonnie

Pinnacle OPE Member
Local time
7:49 PM
User ID
1725
Joined
Aug 22, 2016
Messages
952
Reaction score
1,633
Location
Penn Yan, NY
Country flag
I'm thinking bad rings.
Those soft, rounded edges provide enough surface area to grab an edge. OEM rings would have likely not hung up with a sharper, more square edge to keep the ring flexing tighter to the piston.
I've seen too many ports with absolutely no chamfering run with no problem to blame this solely on that.
Like oem 1127 series.
 

Fruecrue

certified hand catcher
Local time
7:49 PM
User ID
2417
Joined
Jan 4, 2017
Messages
4,391
Reaction score
21,689
Location
Alden NY
Country flag
That is rough. Will you tear it down and split the cases for repair?
Isn't there a chance that left over stuff from the piston is in the bottom of the case?
Just thinking out loud.
I did not split the case, did my best, it's ran since this.
 
Top