Pinging after piston change.

ezmoto
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ezmoto
Edited Date/Time 7/3/2020 3:09am
Hello,

I just did a piston change on my 250yz which have done 80 hours total. It started first time and went racing no problems... But

It has this ping or ding sound and I don’t think it made this sound with the old piston... I think it might be because of the better compression, but not sure.. my buddies said that it did not sound like any motor problems at all, but I’m still a little nervous :/ have anyone tried this before?? Tried to repack muffler and did little to nothing.. it sounds like it’s coming from the front pipe (don’t know the English name)

https://youtu.be/IhHTsXnJHi4
Tried recording the sound..

Hope someone can help :/
|
seth505
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seth505 7/2/2020 7:02am
7/2/2020 7:02am
Are you sure the pipe is seated tight/flush against the cylinder? Pinging could mean a lean condition and louder than normal noises could mean something isn't tight. Those 2 could very well go together.
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ezmoto
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ezmoto 7/2/2020 7:09am
7/2/2020 7:09am
I’m running 95 octane with 10% ethanol, and 3% oil so that should not be it;/ i took a photo of the pipe and cylinder, but can’t get it any closer :/

rjg
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rjg 7/2/2020 7:34am
7/2/2020 7:34am
Piston in backwards?
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ezmoto
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ezmoto 7/2/2020 7:43am
7/2/2020 7:43am
Then it Would have exploded... i sent Racing for 30 min, and im sure i put it in correct

The Shop

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Falcon
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Falcon 7/2/2020 8:35am
7/2/2020 8:35am
Do you hear it when the motor is under high load? My '06 YZ250 pinged under heavy acceleration in a taller gear when going uphill or when I was seated, going through mud. It turned out to need a slightly richer mixture - I went up one on the main jet and leaned out the needle.
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ezmoto
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ezmoto 7/2/2020 8:43am
7/2/2020 8:43am
It is just lodder under acceleration:/ I dont thinks its about jetting or fuel mixture, because begore the piston change everything was sounding crisp! - Could it maybe be the o rings in the exhaust, that are not working properly? I changed Them with the one from my top end kit
CarlinoJoeVideo
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CarlinoJoeVideo 7/2/2020 9:14am
7/2/2020 9:14am
ezmoto wrote:
Try watching the video i linked
Try watching the video i linked
That sounds like a normal YZ. I think it's just your exhaust is blown out. Repack or replace it. I didn't hear anything from the engine thats weird.
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ezmoto
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ezmoto 7/2/2020 9:18am
7/2/2020 9:18am
ezmoto wrote:
Try watching the video i linked
Try watching the video i linked
CarlinoJoeVideo wrote:
That sounds like a normal YZ. I think it's just your exhaust is blown out. Repack or replace it. I didn't hear anything from the engine...
That sounds like a normal YZ. I think it's just your exhaust is blown out. Repack or replace it. I didn't hear anything from the engine thats weird.
Thanks! My buddies also Said that the motor spindes perfect, but i Think the Ping is simple the expasion champer that is bend or the new o rings i put in
Paw Paw
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Paw Paw 7/2/2020 10:01am
7/2/2020 10:01am
Was the new piston an OEM unit or something else?
These engines are built with a squish issue right from the factory and cause problems and then if an after market unit is introduced it can cause even more issues.
Do you see any pitting on the edges of the new or old pistons?

Paw Paw
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ezmoto
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ezmoto 7/2/2020 10:23am
7/2/2020 10:23am
Paw Paw wrote:
Was the new piston an OEM unit or something else? These engines are built with a squish issue right from the factory and cause problems and...
Was the new piston an OEM unit or something else?
These engines are built with a squish issue right from the factory and cause problems and then if an after market unit is introduced it can cause even more issues.
Do you see any pitting on the edges of the new or old pistons?

Paw Paw
Its not OEM, but vertex! But Vertex is a big Company, and my freinds have had no issues with them :/
ezmoto
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ezmoto 7/2/2020 10:27am
7/2/2020 10:27am
Paw Paw wrote:
Was the new piston an OEM unit or something else? These engines are built with a squish issue right from the factory and cause problems and...
Was the new piston an OEM unit or something else?
These engines are built with a squish issue right from the factory and cause problems and then if an after market unit is introduced it can cause even more issues.
Do you see any pitting on the edges of the new or old pistons?

Paw Paw
ezmoto wrote:
Its not OEM, but vertex! But Vertex is a big Company, and my freinds have had no issues with them :/
What do u recommend i do? I see some small nits on the edge of the piston through the exhaust hole... :///
ezmoto
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ezmoto 7/2/2020 10:29am
7/2/2020 10:29am
Paw Paw wrote:
Was the new piston an OEM unit or something else? These engines are built with a squish issue right from the factory and cause problems and...
Was the new piston an OEM unit or something else?
These engines are built with a squish issue right from the factory and cause problems and then if an after market unit is introduced it can cause even more issues.
Do you see any pitting on the edges of the new or old pistons?

Paw Paw
ezmoto wrote:
Its not OEM, but vertex! But Vertex is a big Company, and my freinds have had no issues with them :/
ezmoto wrote:
What do u recommend i do? I see some small nits on the edge of the piston through the exhaust hole... :///
And i run an aftermarket cylinder head from RENALDI, which is Yamaha factory racing
Paul_Pitzonka
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Paul_Pitzonka 7/2/2020 11:45am
7/2/2020 11:45am
If you’re worried about it... drain the coolant and knock the head back off... 30 mins of work and you’ll have your answer to whether or not it’s detonating...
ezmoto
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ezmoto 7/2/2020 11:49am
7/2/2020 11:49am
Paul_Pitzonka wrote:
If you’re worried about it... drain the coolant and knock the head back off... 30 mins of work and you’ll have your answer to whether or...
If you’re worried about it... drain the coolant and knock the head back off... 30 mins of work and you’ll have your answer to whether or not it’s detonating...
How Will it look? I already raced for almost an hour on the piston Smile - A freinds of mine told me that the pinging is because of my compession because of the new piston! But dont know if that could be the case
Paul_Pitzonka
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Paul_Pitzonka 7/2/2020 11:59am
7/2/2020 11:59am Edited Date/Time 7/2/2020 12:00pm
Paul_Pitzonka wrote:
If you’re worried about it... drain the coolant and knock the head back off... 30 mins of work and you’ll have your answer to whether or...
If you’re worried about it... drain the coolant and knock the head back off... 30 mins of work and you’ll have your answer to whether or not it’s detonating...
ezmoto wrote:
How Will it look? I already raced for almost an hour on the piston :) - A freinds of mine told me that the pinging is...
How Will it look? I already raced for almost an hour on the piston Smile - A freinds of mine told me that the pinging is because of my compession because of the new piston! But dont know if that could be the case
As mentioned above... it would look like minor pit marks around the edge of the piston and/or combustion chamber of the head... Yz’s do tend to rattle at idle... If you’re that worried about it remove the head it’s only way to know without a doubt...
ezmoto
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ezmoto 7/2/2020 12:04pm
7/2/2020 12:04pm
Paul_Pitzonka wrote:
If you’re worried about it... drain the coolant and knock the head back off... 30 mins of work and you’ll have your answer to whether or...
If you’re worried about it... drain the coolant and knock the head back off... 30 mins of work and you’ll have your answer to whether or not it’s detonating...
ezmoto wrote:
How Will it look? I already raced for almost an hour on the piston :) - A freinds of mine told me that the pinging is...
How Will it look? I already raced for almost an hour on the piston Smile - A freinds of mine told me that the pinging is because of my compession because of the new piston! But dont know if that could be the case
Paul_Pitzonka wrote:
As mentioned above... it would look like minor pit marks around the edge of the piston and/or combustion chamber of the head... Yz’s do tend to...
As mentioned above... it would look like minor pit marks around the edge of the piston and/or combustion chamber of the head... Yz’s do tend to rattle at idle... If you’re that worried about it remove the head it’s only way to know without a doubt...
Ill remove the head then! Postes the video on another site, and people there Said it was completely normal for a yz to Ping Like mine do, especially when i just put a new piston in.. but thanks for the help, Will post a picture tommorow of the piston head
JMCR250
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JMCR250 7/2/2020 12:23pm
7/2/2020 12:23pm
Both the YZ 250s and CR250s from this era were very highly tuned with a lot of compression. I have an '05 CR250 that pinged on pump fuel from the first day I owned it. I got the jetting dialed in and now run 50/50 pump/VP C12. Runs great with no pinging.

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ezmoto
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ezmoto 7/2/2020 12:46pm
7/2/2020 12:46pm
JMCR250 wrote:
Both the YZ 250s and CR250s from this era were very highly tuned with a lot of compression. I have an '05 CR250 that pinged on...
Both the YZ 250s and CR250s from this era were very highly tuned with a lot of compression. I have an '05 CR250 that pinged on pump fuel from the first day I owned it. I got the jetting dialed in and now run 50/50 pump/VP C12. Runs great with no pinging.
So because og the new piston and better compression i should go with bigger jetting? Smile
ezmoto
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ezmoto 7/2/2020 12:50pm
7/2/2020 12:50pm
Actually just found a video of the First start with new piston (break in) and there were no pinging there!! So its has to be something about the compression
ezmoto
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ezmoto 7/2/2020 12:56pm
7/2/2020 12:56pm
I run 95 octane with 10% ethanol, but my pump in Denmark also have 100 octane with 5% ethanol so ill try that instead!
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sandman768
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sandman768 7/2/2020 2:55pm
7/2/2020 2:55pm
I had a 2000 or 2001 YZ250 that pinged/ detonated after I replaced stock piston with a wiseco. Had to richen jetting a bit for the wiseco piston, back then The YZ”s were right on the edge of detonation ...
Chris99Flannery 7/2/2020 5:44pm
7/2/2020 5:44pm Edited Date/Time 7/2/2020 5:45pm
ezmoto wrote:
I run 95 octane with 10% ethanol, but my pump in Denmark also have 100 octane with 5% ethanol so ill try that instead!
Run race fuel to see if it goes away. With that rinaldi head, my bet is you need quality fuel. Like said earlier stock YZ’s are borderline race fuel anyway.
Dont richen it for the sake of longevity and cost performance , but put the right fuel in and you will get performance and safety.
Yes try that 100octane with less ethanol.
FahQ
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FahQ 7/2/2020 6:00pm
7/2/2020 6:00pm
Did you measure squish before or after the piston change?
I’m thinking either your base gasket is thinner, or your piston compression height is taller.
ezmoto
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ezmoto 7/2/2020 9:31pm
7/2/2020 9:31pm
FahQ wrote:
Did you measure squish before or after the piston change?
I’m thinking either your base gasket is thinner, or your piston compression height is taller.
I did not! :/
ezmoto
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ezmoto 7/3/2020 3:05am
7/3/2020 3:05am
UPDATE:
Here is a picture of the piston! Just Remixes the top end and did 40 min of Racing with the pinging! I Think it looks totally fine
ezmoto
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ezmoto 7/3/2020 3:09am
7/3/2020 3:09am
This is the head. The Marks on the side are from the guy who owned it the First 8 hours... So thats not the problem

ezmoto
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ezmoto 7/3/2020 4:24am
7/3/2020 4:24am
Octane 100 with 5% ethanol dit not help.. stil pings, but puls like crazy, and starts 1 st kick
ezmoto
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ezmoto 7/3/2020 6:36am
7/3/2020 6:36am
The main jet is 190! So it Cant be because of a to lean mix i think

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