125 Rich or lean pic included
- Thread starter 615kawi
- Start date
What plug would you recommend? I'm currently running a br9es.
I'm running 32:1 castor 927
I'm running 92 pump fuel. Should I switch to race fuel like c12? The porting was done for pump fuel.
I'm not sure about head squish but I'm sure Eric handles all that when he does his bore and port jobs.
Thanks paw paw! Really good info as with all your post.
The sleeve was done else where but it was sleeved before I sent it to gorr. Eric bored the sleeve and ported. I agree with you about him standing behind his work. I have not one complaint about Eric gorr. Very nice people and their customer service is the best I ever had from anywhere.
His email keeps getting hacked and I get spammed. I have had two of his bigbore 125's and they work/worked very well.
In the past he hasnt promoted 125's to 134's since it was about the same to make one a 144. but the 134 was a great way to build a legal 125 in the day that had a stronger midrange (due to the retardation of the transfers from boring). Again, yours doesnt look lean to me.
If it was mine I would treat the cylinder with muratic acid to remove the aluminum, light hone on the affected area and 600 grit wet and dry on the piston. new ring. gapped no less than the middle in acceptable range.
I don't usually use a higher oil to fuel ratio for breakin (though companies like yamaha suggest it) on my plated cylinders. I run 20-1 in my 125's constantly. Yamalube. I think if I was having the result you report I would go to a little longer warm up and the 20-1 for at least a couple of tanks. But literally, when mine are runnging clean without the choke/enrichenor I am pulling away.
We didn't talk about how old your spark plug is and looking at it may be trying to read through lots of different conditions if it was used. IE not the ten minutes of age the piston was reported to be. I think you are still looking for at least one air leak, and I would start at the crank seals. If it was mine it would be topend on, bdc and pressurized to about 10 lbs and I would be spraying soapy water everywhere two surfaces met.
In the past he hasnt promoted 125's to 134's since it was about the same to make one a 144. but the 134 was a great way to build a legal 125 in the day that had a stronger midrange (due to the retardation of the transfers from boring). Again, yours doesnt look lean to me.
If it was mine I would treat the cylinder with muratic acid to remove the aluminum, light hone on the affected area and 600 grit wet and dry on the piston. new ring. gapped no less than the middle in acceptable range.
I don't usually use a higher oil to fuel ratio for breakin (though companies like yamaha suggest it) on my plated cylinders. I run 20-1 in my 125's constantly. Yamalube. I think if I was having the result you report I would go to a little longer warm up and the 20-1 for at least a couple of tanks. But literally, when mine are runnging clean without the choke/enrichenor I am pulling away.
We didn't talk about how old your spark plug is and looking at it may be trying to read through lots of different conditions if it was used. IE not the ten minutes of age the piston was reported to be. I think you are still looking for at least one air leak, and I would start at the crank seals. If it was mine it would be topend on, bdc and pressurized to about 10 lbs and I would be spraying soapy water everywhere two surfaces met.
The spark plug was new when I installed the piston. My crank seals are also brand new. I recently restored the bike and everything was replaced. I think I may have found my issue. I think it's due to ring gap issues and cold seizure from improper break in. I just looked at my replacement piston box. The part numbers are slightly different. I'm not sure why put here is a pic of both boxes. If you look at the number right above the bar code they are different. I'm not sure what this number is but it's also stamped on top the Piston. Maybe wiseco just changed the part number? I know both pistons are the same size so it should be fine I would think. Here is a pic
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I would like to see a photo of the piston on the exhaust port side. I see some heat marks on the cylinder at that point that concerns me. Was the piston drilled for lubrication at the exhaust port bridge? That bridge shows that maybe it was not.
I am not sure if the head squish could have been checked or done if all he had was the cylinder to work on.
The plug heat range you are using should be good, but you may want to try a "10" for the next first run of the engine.
Paw Paw
I am not sure if the head squish could have been checked or done if all he had was the cylinder to work on.
The plug heat range you are using should be good, but you may want to try a "10" for the next first run of the engine.
Paw Paw
The piston does have the lubricating ports. He had the head and cylinder when the bore was done. Here is a picture.
I have never checked ring gap when I completed a top end and maybe it finally bit me in the a**? I just check my last 2 piston rings and the current one when it seized. Keep in mind all these rings have very low hrs on them. The ring gap measurements are
.008
.020
.008
These are the 3 rings that were in the bike since the 134 bore. The last one being .008 was in the bike when it seized.
The info for cleaning the cylinder and piston was posted early in the thread. The ring end gap should be between .010" and .012", if memory serves me, but see what the piston paper work called for as well as what is in the service manual. A steel sleeve with a forged piston will be tricky getting the correct ring end gap as the piston expands faster than the cylinder. If manual calls for .080" then I would add a couple of thousands to that to be safe. Remember that a single ring piston rings don't last very long any way.
Paw Paw
Paw Paw
Took the words right out of my mouth.
Exhaust bridge = lubrication holes for piston.@615kawi
What does your air filter look like? Is it coming apart?
I'm looking at the cylinder pic and it's a uniform wear except on the one side it looks like it sucked something in like a little piece of foam or aluminum.
I would also like a better look at each side of the piston where it is worn.