Author Topic: 310 Heat seize (Read 12489 times)

xTHUNDERCATx · « **on:** October 18, 2014, 08:45:55 PM »

I'm looking for opinions as to what caused this. Pro-x 310 with esr port work, 38mm airstryker, trx11 pipe, in oregon. With a 184 main jet it would bog, 182 main i could walk it through the full throttle, at 180 main I could ride it. I had been playing with the jets on flat ground, once I had the bog cleared I(assuming it was fat) I went to run it up banshee hill. I made it 3/4 of the way up the hill before the bike heat seized. Coolant temps during flat ground runs were 185-190 (made probably 6-7 long runs). So the question is why did it seize, am I just dumb and ran it lean? I did find the silencer core was not aligned I can speculate at what that may cause but I wanted to get some more educated opinions on what may have caused the seize.
Click on the piston photos for larger versions.

hickwheeler · « **Reply #1 on:** October 18, 2014, 08:57:30 PM »

I was just at sand lake last weekend. mine is a ct330 with no porting. It has a trx5b cm and led air box eliminater. I was running a 192 main. Mine might of been a touch lean. Are you sure that was not a lean bog you were experiencing.

udontknowme · « **Reply #2 on:** October 19, 2014, 02:08:59 AM »

well if your preference to determine jetting is by the brown ring, it appears pretty small from what i can tell. all my experience with main jets to large is the engine acts like theres a rev limiter, never have they bogged like you describe. plus if it was so rich it wouldnt run full throttle, 2 jet sizes smaller wouldnt make it seize. maybe the silencer was the problem. never had that problem so im not sure what it would do

whats the bottom of the piston look like ? what oil and ratio you using ?

Pumashine · « **Reply #3 on:** October 19, 2014, 09:16:42 AM »

Quote from: xTHUNDERCATx;44718

I'm looking for opinions as to what caused this. Pro-x 310 with esr port work, 38mm airstryker, trx11 pipe, in oregon. I wanted to get some more educated opinions on what may have caused the seize.

Is the cylinder broke in? I once fried my 250 at Winchester with a fresh bore and new piston at the end of the day. (Of course it was the end of the day cause you can't ride anymore)

xTHUNDERCATx · « **Reply #4 on:** October 19, 2014, 09:59:00 AM »

It may have been a lean bog hick, I'm not to sure at this point. udontknowme, thats what I was kind of hoping to find out, if it wasnt bogging from being rich something was causing it. It was a fresh motor puma, I had maybe 3/4 a tank of gas through it at that point.

Pumashine · « **Reply #5 on:** October 19, 2014, 10:06:18 AM »

Quote from: xTHUNDERCATx;44740

It was a fresh motor puma, I had maybe 3/4 a tank of gas through it at that point.

The reason I asked is cause that sorta what my piston looked like. After 1/2 day of taking it easy I towed my sister back to the parking lots when her chain broke. 1/2 way there it seized up. Sand really takes alot of horsepower to move through. Good thing is you just have to put in a new piston. Hand sand or some use Muriatic acid the get the aluminum off the cylinder walls.

xTHUNDERCATx · « **Reply #6 on:** October 19, 2014, 10:15:53 AM »

Thats what I was hoping was that I could save the bore, for now I'm throwing my stock cylinder back on. I may wait to try this 310 again tell I can upgrade a few other things with it (cr ignition, new radiator, and other small goodies).

xTHUNDERCATx · « **Reply #7 on:** October 19, 2014, 10:25:51 AM »

Quote from: Pumashine;44741

The reason I asked is cause that sorta what my piston looked like. After 1/2 day of taking it easy I towed my sister back to the parking lots when her chain broke. 1/2 way there it seized up. Sand really takes alot of horsepower to move through. Good thing is you just have to put in a new piston. Hand sand or some use Muriatic acid the get the aluminum off the cylinder walls.

If I used the acid to get the piston deposits off is that something were I just need to be careful not to transfer the acid to the actual cylinder?

Pumashine · « **Reply #8 on:** October 19, 2014, 10:35:59 AM »

Quote from: xTHUNDERCATx;44747

If I used the acid to get the piston deposits off is that something were I just need to be careful not to transfer the acid to the actual cylinder?

You can't ask me but I know I have heard this a number of times. You are right about not wanting the stuff on the rest or the cylinder as it will eat that away also. I just use 220 to 400 wet or dry sandpaper it hot soapy water. Cross sand until the aluminum disappears. You would have to work for hours to do any damage to the steel sleeve. After rinsing completely put a liberal amount of wd-40 on the steel sleeve or it will rust quickly.

hickwheeler · « **Reply #9 on:** October 19, 2014, 07:58:40 PM »

I had to use muriatic acid on my 03 yz250 cylinder once. It is pretty easy. I just used a qtip and kept rubbing till the aluminum was gone. It shouldn't effect the steel sleeve. That piston seized from my pilot jet getting crap in it.

Daniel370r · « **Reply #10 on:** October 19, 2014, 08:27:31 PM »

I had the same issue with my 370 when I first built it. I did several heat cycles was rich by a couple jets and mine 4 corner seized. Allan knowles told me it was from not breaking it in properly and holding the throttle it at 3/4 throttle to long causing it to lean out. I was running down the pavement went through the gears then was in 6 th 3/4 throttle for a min locked up tight. Not sure if he was right but I thought the tolerance was to tight and when it heated up wasn't any room to expand. Just my opinion tho

Daniel370r · « **Reply #11 on:** October 19, 2014, 08:29:17 PM »

If you got it from Eddie he would probably bore or hone it for free just have to get a piston.

Pumashine · « **Reply #12 on:** October 19, 2014, 09:04:25 PM »

Quote from: Daniel370r;44763

If you got it from Eddie he would probably bore or hone it for free just have to get a piston.

Why would you bore a fresh bore with an hour on it?

Daniel370r · « **Reply #13 on:** October 19, 2014, 10:02:26 PM »

Didn't read every comment.Looks like it four corner seized mine was trashed had to be bored. Was just stating that if it needed bored or honed Eddie would probably do it for free.

udontknowme · « **Reply #14 on:** October 19, 2014, 10:04:54 PM »

Quote from: Daniel370r;44762

I had the same issue with my 370 when I first built it. I did several heat cycles was rich by a couple jets and mine 4 corner seized. Allan knowles told me it was from not breaking it in properly and holding the throttle it at 3/4 throttle to long causing it to lean out. I was running down the pavement went through the gears then was in 6 th 3/4 throttle for a min locked up tight. Not sure if he was right but I thought the tolerance was to tight and when it heated up wasn't any room to expand. Just my opinion tho

good ol allen. i would have to question his competancy if he made a statment like that. alot of people follow some voodoo break in routine but its all nonsense. if it wont go full tilt within the first few minutes then a 1000 heat cycles aint gonna make any difference. probly had your clearance to tight or something along them lines.