Just a word for those that feel more oil will stop detonation caused by a lean mix.
Adding more oil will just make the mix even leaner.
Locked up
- Thread starter blaster003
- Start date
Adding more oil will just make the mix even leaner.
Ok found out it was running lean and it did not lock up because it was lean the clip that holds the piston on the rod fell off and it tore up my cylinder and piston but I'm getting a re bore and new piston soon but the clip is in the bottom end noe I think cause I couldn't find it unless it got destroyed and sorry I don't know how to upload pics anyone know a good piston
Oooo. That's not pretty man, sorry to see that on such a fresh motor. Better tear those cases apart to make sure they are thoroughly cleaned and might as well throw in new bearings since your in there and just in case anything got into them. A speck of debris will cause havoc on the bearings. Make sure to follow breakin procedure and leaktest when you get it back!
I'd take the cylinder off and take the bottom end to a shop and get them to split it. Then, I'd clean it obsessively and take it back to them to press them back together.
I don't know what level of a build you're going to try to do, but we can start making recommendations now if you can let us know. As long as your crank is true and your bearings are okay and you get the cases clean, you're off to a great start. A simple rebuilt with a fresh piston, bore, hone, seals, and gaskets all assembled properly, followed with a leak down test, compression check, proper jetting selection, heat cycles, and break procedure in will get you running like a top.
Porting and a re-cut head with a decent pipe will be a little more cost intensive and will definitely wake it up, but those aren't much more of an issue. If you want to DIY for all of those things, you'd best start planning immediately.
Answers needed! Budget should be included with the answers.
Remember, having it rebuilt by a shop will take several hundred more dollars, which is money that could be put towards some go fast goodies. The CR250R that came through the shop a week or so ago was done for $900 and the engine was out of the frame. With it in frame, it would have been close to $1200. You can do it yourself for close to $400-$500. That's $700-$800 that will get you a filter, used pipe, cut head, and porting with all the jets you'll need. If you want to go with a simple rebuild or a more powerful solution, all you have to do is ask. Not knowing is your fault if you have access to this site.
I don't know what level of a build you're going to try to do, but we can start making recommendations now if you can let us know. As long as your crank is true and your bearings are okay and you get the cases clean, you're off to a great start. A simple rebuilt with a fresh piston, bore, hone, seals, and gaskets all assembled properly, followed with a leak down test, compression check, proper jetting selection, heat cycles, and break procedure in will get you running like a top.
Porting and a re-cut head with a decent pipe will be a little more cost intensive and will definitely wake it up, but those aren't much more of an issue. If you want to DIY for all of those things, you'd best start planning immediately.
Answers needed! Budget should be included with the answers.
Remember, having it rebuilt by a shop will take several hundred more dollars, which is money that could be put towards some go fast goodies. The CR250R that came through the shop a week or so ago was done for $900 and the engine was out of the frame. With it in frame, it would have been close to $1200. You can do it yourself for close to $400-$500. That's $700-$800 that will get you a filter, used pipe, cut head, and porting with all the jets you'll need. If you want to go with a simple rebuild or a more powerful solution, all you have to do is ask. Not knowing is your fault if you have access to this site.
According to the pics, the concrete looking stuff on the piston crown is carbon, and an awful lot of it if it is from an engine with only 200 miles on it.
If a piston pin circlip came out on one of my engines from a builders refurbish, I would be on his doorstep asking for a warranty claim, I have never known them to come out if installed correctly.
I double dog dare anyone to install a new circlip correctly, and then ride the crap out of the engine until the circlip removes itself from its position in the piston.
However if you re use a circlip or do not install it correctly, there is a great chance that it will migrate and try to get down the transfers.
Last edited:
Yeah, I forgot to say something about that. The concrete textured description made me think detonation. Buildup never crossed my mind. Well as long as your head isn't pitted, you can clean and reuse it.
I do know that you're going to need it bored. From what I can tell, it looks like it's pretty close to .080 over the current size.
I do know that you're going to need it bored. From what I can tell, it looks like it's pretty close to .080 over the current size.
Did you look at the pics that piston is trashed an so is the cylinder wall, it looks to me that it caught the ring in the port due to either being not installed properly or no port chamfer grabbing the ring, the damage i see wasn't caused by a wrist pin clip coming out
I would lay a dollar on the theory that it was a circlip, judging on the position of the scoring in the bore.
However I do see no chamfering of the ports.
The circlip may have clipped a ring and jammed it out the exhaust port.
Although the rings and piston are damaged on the front of the piston, I see no damage to the cylinder near the exhaust port, which leads me to believe that is was a migrating clip starting the course of events.
Wether caused by a clip or by non chamfering of ports, I would be complaining to the builder, this damage was not caused by operator error!
However I do see no chamfering of the ports.
The circlip may have clipped a ring and jammed it out the exhaust port.
Although the rings and piston are damaged on the front of the piston, I see no damage to the cylinder near the exhaust port, which leads me to believe that is was a migrating clip starting the course of events.
Wether caused by a clip or by non chamfering of ports, I would be complaining to the builder, this damage was not caused by operator error!
The more I look at the pics of the cylinder, the more I become concerned.
After only 200 miles of riding there should still be a lot of crosshatching visible in the bore.
Was this cylinder bored and honed correctly, or even bored at all.
There should be signs of machine marks on the piston, but I see none, the focus is clear as I can see fingerprints, but no signs of machining.
Is this a hack job? An old piston in a worn bore, with used circlips.??????
I have been around 2 strokes a very long time, and things here do not compute.
The builder was not RAG Engineering by any chance?
If you look closely at the wrist pin boss on the piston you can lust see scoring where the clip migrated.
Last edited:
Yeah, I see those marks and I'm with Blaaster. There's more than one must-do things that weren't done. I'd be going to the builder.
I do now see the scratch were it looks like the clip came out, didnt see that till blaaster blew the pic up
Sorry to keep harping on, but the wrist pin boss seems to be protruding well outside the extremities of the piston!
I was fixating on it for a bit, but the original picture of the piston makes it look a little better. Well, the boss at least.
Again looking at that piston, you can just see the machine marks above and near the pin boss.
That piston has done a lot more work than 200 miles, I pulled a piston from an original 2005 engine with countless hours on it and there was still most of the piston machining and some crosshatching in the bore.
I am definatley suspecting foul play!
That piston has done a lot more work than 200 miles, I pulled a piston from an original 2005 engine with countless hours on it and there was still most of the piston machining and some crosshatching in the bore.
I am definatley suspecting foul play!
The machine marks on the boss make me think that the boss wasn't protruding. I think that comes from having touched the transfers a million times over that 200 miles and having grabbed some suspended gas/oil droplets.
Now the piston as a whole... That's not a good statement to the builder. I'll agree that the piston has been a victim to more than the circlip. Cheaping out on the builder's behalf is what it looks like to me.
You need to go to that builder and fix it. If you don't, you're going to be out of several hundred more dollars for the rebuild. Is a 20 minute argument worth the price of a new engine? Not from him, I bet it isn't. I'd absolutely demand that he give me the money to rebuild it myself. That way, you know it's right. When you do approach him, and I sure hope you do, take what we've said as fact. There's a great deal of experience here. Hell, Blaaster was modifying locomotives when they were the hot new thing.
Now the piston as a whole... That's not a good statement to the builder. I'll agree that the piston has been a victim to more than the circlip. Cheaping out on the builder's behalf is what it looks like to me.
You need to go to that builder and fix it. If you don't, you're going to be out of several hundred more dollars for the rebuild. Is a 20 minute argument worth the price of a new engine? Not from him, I bet it isn't. I'd absolutely demand that he give me the money to rebuild it myself. That way, you know it's right. When you do approach him, and I sure hope you do, take what we've said as fact. There's a great deal of experience here. Hell, Blaaster was modifying locomotives when they were the hot new thing.
Similar threads
