Golf circlip decides to go travelling... (pics)

[brages]

Hi folks.

Here's what I found when I opened up my BIL's ms290... it ran once after I "fixed" it with a Golf piston and the acid treatment on the bore:

Looks like the same ol' story: Too deep of a groove in the piston, so the pin is retained only by the clip ears... which soon succumb to the pounding and go on a bit of a walkabout... hilarity ensues...

 

[Roanoker494]

To tell you the honest truth, I teared up a little when I seen the pictures. Poor old thing didn't deserve that............ LOL

I have heard of the clips coming loose and causing major problems, but this was the first time I have ever seen it.

 

[mtngun]

Looks like the same ol' story: Too deep of a groove in the piston, so the pin is retained only by the clip ears... which soon succumb to the pounding and go on a bit of a walkabout... hilarity ensues...

Good call, thanks for the reminder.

 

[Trigger-Time]

Am not knocking anyone for using Golf, but the only way I would use Golf. If OEM is NLA.
Over the 4 years here on AS, I have seen way to many threads just like this one.
Some guys use after market piston but use OEM clips.
This is also a big problem with alot of ebay saws.


TT

 

[subhunter]

How did your jug look after that? I had one look about the same and the jug was junk afterwards also. Sure hurt my feelings when that thing blew after running only two cuts or so.

 

[ttyR2]

Is the gap between the ends of the wrist pin too big to allow the use of teflon buttons? I've used them in race engines before.

 

[brages]

How did your jug look after that? I had one look about the same and the jug was junk afterwards also. Sure hurt my feelings when that thing blew after running only two cuts or so.

There are some notches on the bottom edge of the intake port and a few dings on the top of the combustion chamber. To be honest, the cylinder didn't look that great after my acid cleanup job anyway, so I didn't have too high of hopes.

I got extremely lucky last week when I bought a box of "misc Stihl parts" from a local lawn and saw shop for $5.50 -- besides a scabbard and a coil for a ts800, it contained an unidentified piston and cylinder. Just happened to be a 290 P&C in very good condition!

 

[fidiro]

Am not knocking anyone for using Golf, but the only way I would use Golf. If OEM is NLA.
Over the 4 years here on AS, I have seen way to many threads just like this one.
Some guys use after market piston but use OEM clips.
This is also a big problem with alot of ebay saws.


TT

I have been looking for a piston for my Makita DPC7311 and was going to get the GOLF. Do you think that this happened because the clips that come with the Golf piston are faulty? Has this failure happened before with this piston?

 

[timberwolf]

Not sure it would have prevented the failure, but I tend to put tail up on the clips. Sounds weird, but there is a greater acceleration at TDC than BDC and having the tails up holds the ends more secure so there is less vibration and fatigue.

 

[AUSSIE1]

For cheap insurance use OEM clips.

Some clips don't have the spring quality of OEM and there can be a difference in wire dia.

 

[Mike mandry]

not sure it would have prevented the failure, but i tend to put tail up on the clips. Sounds weird, but there is a greater acceleration at tdc than bdc and having the tails up holds the ends more secure so there is less vibration and fatigue.

+1

 

[SawGarage]

did the clip end break, or was it possibly not seated all the way???

 

[brages]

did the clip end break, or was it possibly not seated all the way???

The clip end broke... but I cannot guarantee it wasn't seated all the way. This seems unlikely to me, though. I have had lapses of attention, but that would be extreme. I believe the groove for the clip was made too deep.

The Episan piston I put in an 026 recently had a one-eared clip that seemed a lot thicker. I liked that design better.

I guess I could test the "deep groove" hypothesis by putting the good clip in that side and hammering on the pin to see if the ear breaks...

 

[AUSSIE1]

The pin wears down the tags but I don't think it ever goes all the way through. It depends on how much chamfer on the pin. Give one a few minutes run time and there is evidence of the pin rubbing on the tag. The chamfer on the pin would cause the pin pressure on the tag.

 

[Trigger-Time]

I have been looking for a piston for my Makita DPC7311 and was going to get the GOLF. Do you think that this happened because the clips that come with the Golf piston are faulty? Has this failure happened before with this piston?

I think some of them have to big of a groove for the clip.
That lets it come out while saw is running.
Many have lost good cylinders over clip flying out.

Am not the luckiest guy, and I just won't take the chance.
I have Meteor 066 piston I bought over 2 years ago still
in the box. Just could not make my self use it. If going AM
I would use a Meteor way before Golf.


TT

 

[dk27]

I had an ear break off a circlip with the exact same results as that.

 

[SawGarage]

I had an ear break off a circlip with the exact same results as that.

Which piston??

 

[mowoodchopper]

I think some of them have to big of a groove for the clip.
That lets it come out while saw is running.
Many have lost good cylinders over clip flying out.

Am not the luckiest guy, and I just won't take the chance.
I have Meteor 066 piston I bought over 2 years ago still
in the box. Just could not make my self use it. If going AM
I would use a Meteor way before Golf.


TT

meteor are good pistons,I have had good luck

 

[dk27]

Which piston??

Golf

 

[fidiro]

I wish I could get the meteor instead but contacted the greek on ebay and the response was that there is not one made for the 7300's.

I also contacted a member here on AS and did not get a response so I figure it doesn't exist.

I wound up ordering the Golf but really wanted to see a Meteor.