150 miles on a new motor and this

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Ok so now I’m worried. I purchased new emgo pistons for my engine rebuild and Hastings rings and circlips. The engine is back together and in the bike with a completion/ first startup date in December or January. I feel as if I checked the circlip and ring installation numerous times. Should I be concerned about my choice of pistons or rings/ circlips?
 
Amen...… At the point you're at I'd churn and burn, though with a careful run in. That's just me and would be my decision providing those circlips are up to snuff.
 
Scout63 said:
Ok so now I’m worried. I purchased new emgo pistons for my engine rebuild and Hastings rings and circlips. The engine is back together and in the bike with a completion/ first startup date in December or January. I feel as if I checked the circlip and ring installation numerous times. Should I be concerned about my choice of pistons or rings/ circlips?
Click to expand...

Did you put in the wire circlips? Did you put in flat circlips which have a rounded edge? If rounded edges, did you put the rounded edge towards the outside of the piston?

If you answer yes to the first and third questions, tear it down.

If rounded edges and you were oblivious to which way to put the rounded edges, either tear it down, or worry yourself and suffer sleepless nights.

Remember, Murphey's Law .... If there are two ways to install something and you are oblivious to which way is right, then it is guaranteed to be installed wrong.

If you used square edge circlips (both sides), carefully installed them ensuring they were fully seated in the lands, sleep well.

Slick
 
Scout63 said:
Ok so now I’m worried. I purchased new emgo pistons for my engine rebuild and Hastings rings and circlips. The engine is back together and in the bike with a completion/ first startup date in December or January. I feel as if I checked the circlip and ring installation numerous times. Should I be concerned about my choice of pistons or rings/ circlips?
Click to expand...

The pistons and rings are fine. But if you used the circlips that came with the pistons I would replace them before I even start the motor. I have seen too many failures just like Pete's.
 
Have no idea of hijacking, just found it was the place for that instead of creating a new thread.

Glad I was busy enough to keep me away from reassembling the engine with the +.020 JCC pistons.

So what do you think about the circlip groove

150 miles on a new motor and this


And the circlip
150 miles on a new motor and this


Should I buy new ones from AN to be sure?

150 miles on a new motor and this


And what about rings? Don't even know where they come from...
 
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texasSlick said:
Did you put in the wire circlips? Did you put in flat circlips which have a rounded edge? If rounded edges, did you put the rounded edge towards the outside of the piston?

If you answer yes to the first and third questions, tear it down.

If rounded edges and you were oblivious to which way to put the rounded edges, either tear it down, or worry yourself and suffer sleepless nights.

Remember, Murphey's Law .... If there are two ways to install something and you are oblivious to which way is right, then it is guaranteed to be installed wrong.

If you used square edge circlips (both sides), carefully installed them ensuring they were fully seated in the lands, sleep well.

Slick
Click to expand...
No to the first question, flat circlips installed that came with the pistons with the sharp edges to the outside (non-piston) side. I spun the circlips to make sure they were seated. I’m not going to pull the head and cylinders again. Everyone has their own caution vs. laziness comfort (discomfort) point. If I lose a circlip you all will be the first (second) to know.
 
NKN said:
Have no idea of hijacking, just found it was the place for that instead of creating a new thread.

Glad I was busy enough to keep me away from reassembling the engine with the +.020 JCC pistons.

So what do you think about the circlip groove

150 miles on a new motor and this


And the circlip
150 miles on a new motor and this


Should I buy new ones from AN to be sure?

150 miles on a new motor and this


And what about rings? Don't even know where they come from...
Click to expand...

Hi NKN

I have EMGO +.0020" pistons in my MK3, I bought clips from A/N and used Haistings rings. All run in and happy memories of riding in Northern Spain this summer.
 
comnoz said:
Just check the distance between the rod ends with the crank at BDC and then again at TDC. They should be the same distance apart in either position.

Realistically they are seldom perfect. -.005 difference is not uncommon. -.010 is difference is not so good.

This is a fairly common problem when the crank is ground by someone not familiar with these old rubber cranks.

Check it like this.
View attachment 13350 View attachment 13351
Click to expand...
I just checked the crank on one of my motors and I see a 0.030" difference between TDC and BDC so I have an issue! I checked it a bunch of time by pushing the rods so that they were gently loaded inwards but the results were always the same. Weird thing is that the crank has never been reground and the only time it has been apart is when I cleaned out the sludge traps and I was pretty scrupulous about cleanliness and torqueing the studs.
 
When I started racing I was never comfortable with the circlips that came with the Hepolites (even with the sharp side out) and this was back when you could buy genuine Hepolites that came with proper rings and circlips. So I made some shallow teflon buttons to back up the clips. The buttons took care of the clip problem but then (because of the RPM/piston speeds I was pushing) the top rings would break after pounding out the ring lands - the pistons wouldn't make it through a racing season because the rings were too thick and heavy. I had to go to Wiseco for a solution.
 
Yorkie said:
I just checked the crank on one of my motors and I see a 0.030" difference between TDC and BDC so I have an issue! I checked it a bunch of time by pushing the rods so that they were gently loaded inwards but the results were always the same. Weird thing is that the crank has never been reground and the only time it has been apart is when I cleaned out the sludge traps and I was pretty scrupulous about cleanliness and torqueing the studs.
Click to expand...

That sounds like a problem, but then if it's been working fine and isn't showing unusual wear on the bearings or pistons then I'm not sure I would worry about it.

But if your not sure of it's history I would send it to a crank shop.
 
kommando said:
It's not just possible but 100% certain they are made by JJC of Taiwan, as are Emgo and Cycle craft pistons. Under and inside there will be JJC cast into the piston.

http://www.jcc-tw.com/en/
Click to expand...

I have not fitted any of the new [JCC] Hepolites
Do you know if the JCC pistons sold as Hepolites come with black circlips in a red plastic bag like the Emgos do?
150 miles on a new motor and this
 
Its an absolute shame these are in circulation.
A known defect that can destroy an engine, perhaps causing an accident.
Every one should be recalled, or at least have proper circlips replaced.

I thank my lucky stars for this website to bring it to my attention.
 
I also thank everyone for alerting us to this problem. A lot of swearing could have been averted if decent circlips and also decent rings were supplied by the manufacturer. A pity as the pistons themselves seem to be well made.
I did buy Hastings rings to go with my Emgo (JCC) pistons and with of the advice of blokes on this site I have ordered new circlips. Should be all set now.
 
In need for new rings, received a quote for some Hastings stuff from England. Could somebody tells me if it's the good size for a 1974 850 Commando:

73mm STD bore with 1/16 x 1/16 x 5/32 grooves in, +.020”
 
NKN said:
In need for new rings, received a quote for some Hastings stuff from England. Could somebody tells me if it's the good size for a 1974 850 Commando:

73mm STD bore with 1/16 x 1/16 x 5/32 grooves in, +.020”
Click to expand...
if you have a 850 with 77mm std bore , please don't buy 73mm rings ........
 
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