blew it up again, no good!

[Tedh98]

- trick 114 with 927 premix, at 44:1 sometimes 50:1

If you are on a 125, this is a big part of your longevity problem. 

[miedosoracing]

Ok, I'm a bit confused and alittle mad at the "tuner."  So, was the bike running when you took it too him? I build motors quite often.  A reed, is basically plastic.  Your motor will take a piece of aluminum from a piston and still not take out a crank many times, so I'd be really really suspicious of someone claiming a reed did.  So I really need to know if the bike was running when taken down.  I'm calling BS and really would like to see this motor.  Alittle dirt also has nothing to do with a reed breaking off. A reed breaks off, if it is flexed back and forth too far and too much.  When is the last time you had reeds replaced?  If the motor was running fine when you took it in. "TAKE THE MOTOR BACK from the tuner."  Man, I'm getting madder by the word.  The cylinder will not score from a reed either. So WTF is going on?  A reed when breaks off also makes the bike run bad, it will gulp for air when you let off and then get back on the throttle.  It won't idle in many cases. It will feel like you have carb problems.

[miedosoracing]

well me and my dad usually do all the bike work during the week. we usually change oil ever 2 to 3 rides airfilter all the usual bike work, since its 4 days before the loretta lynn qualifier we took it to my engine builder to have him go through it. he said he found some dirt, which broke the reeds, and then the reeds got sucked into the cylinder and bottom end. so all in all it was a snow ball effect. its ok. i talked to my mom, we are either buying a 2011 250sx, which there is only one in washington, or we might get a 2011 250f so i can ride the national if i get my pro points in time, and fix the 250 2stroke to race and practice on.

this statement sounds like you took it in just to have it looked at and freshened up. 

[VintageBlueSmoke]

This is interesting but will be very hard to diagnose online but here goes: We don't have enough information to identify your previous failures but maybe some of the information will trickle back. From what you have told us, you have a pretty well maintained machine and put a lot of hours on it. Reed failure is not uncommon but I tend to doubt that the pieces of the reed were sucked into the bottom end and caused a failure. More likely, the reed cracked and caused a lean condition. This could cause detonation and overheating and will cause a seizure.

I doubt it is oil related though I wouldn't suggest 50 to 1 (anymore). As much as you don't want to hear this, I'd suspect jetting FIRST! I would run the manufacturers (either bike or oils) recommendations, get a few good readings on fresh plugs and keep an eye on ring/cylinder wear; changing piston/rings more frequently if necessary.

I also would suggest (and I can't believe I'm saying this) getting the 4$. You sound like you are attempting to become an AMA Pro rider. Unless you are willing to be a martyr to the 2T cause (and you'll be all our hero if you do), you'll need the thumper experience at the pro level.

[miedosoracing]

And I'll disagree. The OEM's will force him to switch when and if he is a ProAMA rider, either through being good enough to get a factory ride, or by ProAMA rules.  Not one of the current ProAMA riders have had a problem adapting to the 250F.  Plus he would be at a disadvantage at Loretta Lynns.  Those rules are still 250cc vs 250cc. Why bring a stick to a gun fight.  

Have your father or mother call Miedoso Racing today 214-316-3055.  I'd like to speak to them, and I'm not trying to gain your business or anything like that. I'm really worried you are being taken advantage of. My first red flag is telling you to buy a new cylinder. No I mean NO reputable race shop buys new cylinders, they send away to one of 3-4 recoating companies for $100.  Cost to client, about $150-200 usually.  No $700 cylinder. Period. Then the whole dirt took out a reed etc BS.  please tell them to call me. Thanks

[yo_marc]

Curious.. would a broken carbon fiber reed be more prone to invoke damage vs a fiberglass/resin/plastic/whatever one?

Miedoso - props for looking out for this guy..

[MyckMcClung]

"trick 114 with 927 premix, at 44:1 sometimes 50:1

If you are on a 125, this is a big part of your longevity problem. "

Agreed XInf.

I also agree with miedosoracing. You are getting screwed!!!!!
Find a new mechanic, start running 32:1, 36:1 premix, Drop that 927 crap, and use klotz or Lucas. The lucas seems to burn cleaner and is not as gummy, But the Klotz is the best stuff out there. Change the rings every 3 races, the piston every 6, and the lower end every 12.
Then punch that guy that's been doing your engine work in the mouth.

[Coop]

Not that I am piling on, but I agree with Miedos and Myck. I think your mechanic is taking advantage of you. And if you are racing as hard as it sounds, I think your jetting and the fact that you may not be keeping the top end fresh is the cause of your problems. Just because the bike seems to run fine doesn't mean it is jetted properly. I don't know how many races you run, but Myck's guidelines are pretty spot on. Other than the Klotz comment, I hate that stuff...

[MCGRIDDLE_321]

so here is what happened at the track...

i was going out for the 4th practice of the day, i warmed up the bike good then took a site lap around the track (check lines and continue to warm bike up) i did one hard lap and as im coming to the finish line section the bike bogs i would say 3 or 4 times, so i pulled to the side of the track to try and keep it running but it bogs out bad. i tried starting it, check compression with my hand, everything seem good. i pushed it back to the truck, we then took spark plug out to see how it looked and to check spark, the plug looked black, we put a new plug in. it fired up 2nd kick. i warmed it up listening to the motor sounded fine until you got to about 1/2 to 3/4 throttle and then it had a big bog. the bike kinda sounded like if you were to start your bike with no air filter. i rode it in the pits to see if i could feel anything and listen to it. it didnt want to run all that great so i put it on the stand and got undressed and took it to the guy who builds my engines.

now the thing that gets me is. if it ran when i took it to him, how does something claimed to have that big of damage run? now im not bagging on my engine builder (family friend and he has always been there to help me) at all im just confused.

i talked to my dad this morning, i have a friend who has a 07 ktm 250 (same bike) and we are going to try and barrow his for the weekend and have mine rebuilt, just with how money sits we might get a newer 250 sometime in the summer.

i would love to be the guy who trys to qualify on a smoker for some of the nationals, but as it being my first time trying to qualify i want to do good and i know as long as im not paying for all the entrys with my own money my mom and dad will want me on the 4stroke. now sometime in the near future when my mom and dad stop helping out, i will definitely try on the smoker. but just knowing my mom and dad i know it wont happen if they are paying for it.
Josh

[miedosoracing]

Ok, so it sounds like it wasn't running fine. Let's start there. Ask to see the engine apart. The piston should be scratched up and the top of the piston should have pings in it from metal hitting it and the head.  The cylinder, you will be able to look at it and see scratches.  Have him show you exactly what he is talking about.  This should be a much cheaper thing, even if it is complete bottom up to top bad.  Cranks, coating the cylinder and the new piston with seals and gaskets. You should be able to see everything and he can explain why he says what he says.  The question I guess i'm having, is when is the last time you did a crank?  You had mentioned 3 motors now completely rebuilt. So that should be a new crank.  It sounds also like a previous poster may have been right about the reeds leaning out the mixture and running you lean to have your crank seize.  I can't tell from posts on here, but more info after you see it will tell the truth.  Maybe take some pics of the motor apart. The cylinder, the piston and even the crank. 

[miedosoracing]

As for your parents wanting a 4 stroke, they had to have someone tell them that.  Parents just don't know about 4 strokes and 2 strokes.  There has to be someone else who is telling them they are better.  Tell them any day, we can compare complete rebuilds and prices and see if they still like those.  A 250 2 stroke should last 3 times as long as a 250F piston and crank wise.

[MCGRIDDLE_321]

the only reason i say my parents is because my dad races to. so he races a 4stroke and he cant ride 2strokes and wont. it also doesnt help im 195 pounds and a 125 is going to be hard to carry my weight and they both just want the best for me. and the only reason i would get a 250f is to race the national. and i would probably still race my 250 2stroke locally and for loretta's.

[Coop]

Parents just don't know about 4 strokes and 2 strokes.  

Sorry I have to disagree with this, it is too broad a generalization. Just because you are a parent doesn't mean you don't ride or know about bikes   . I know many guys who ride and have kids that ride and they really know their stuff.

[KTMguy]

That's wierd man, maybe it's those first year of that body style KTM's. I know the first 144's had crank problems that they later addressed.

I've got an 09 250sx that I ride at tracks pretty frequently, and race now and again. I like to wring it out too. I'm still on the stock top end and clutch! it's getting tired though.

I mix it 60:1, following the manual, while using fully synthetic pre-mix and 92octane.

[MCGRIDDLE_321]

That's wierd man, maybe it's those first year of that body style KTM's. I know the first 144's had crank problems that they later addressed.

I've got an 09 250sx that I ride at tracks pretty frequently, and race now and again. I like to wring it out too. I'm still on the stock top end and clutch! it's getting tired though.

I mix it 60:1, following the manual, while using fully synthetic pre-mix and 92octane.

ive actually been starting to wonder the same thing. maybe its just that year.