First race- something blew, engine problems

[tazman7]

Had my first race today- Heard a pinging and popping in practice, thought it was the jetting, but the plug looked good.
Went out and raced and my engine died after knocking and pinging, it will start but there is a bad knock and I have to press gas to keep it running, I only ran it for about 5 seconds to show my grandpa.

What should we look for? He thinks it is a bearing, somebody mentioned that it could have thrown a rod, but he said it wouldnt run if it did that-

What would you check first?

Is there any good mechanics around Rochelle Illinois?? (Byron area)

[250R-Dee]

Yep, that sounds like a serious internal problem. If you have basic tools you can tear the engine apart yourself.

[beerock]

main bearing could have blown, they will run with blown main bearings but when they start disintergrating thats when it can break the rod and ruin cylinders etc.

[tazman7]

Yeah we have more tools then most engine shops-no joke!

We are going to rip it apart as soon as I can walk better,

[tazman7]

Now that I am thinking about it, it was doing it on the practice laps only in third gear- and it was in third gear when it blew- could it have broke a tooth or something? Or do you still think it is the main bearings?

[beerock]

Originally posted by tazman7
Now that I am thinking about it, it was doing it on the practice laps only in third gear- and it was in third gear when it blew- could it have broke a tooth or something? Or do you still think it is the main bearings?

sound slike you know motors and tools so you would know only way to really find out is to open her up

[tazman7]

Ok we ripped it out- The rod bearing that is on the crank was bad- Thank god the cylinder walls looked good, I was thankful for that because im running low on fund and that would be alot more expensive to fix then what is wrong with it- I think.

[beerock]

wait, sometimes when those rod bearings go bad they wear the bore out of round and did you check the cylinder and make sure it has no marks?

i would bore it if i was you but if you dont, and you put a new crank in and the broe is worn then youll break a piston.

make sure..

[tazman7]

Ok, I will put a mic on it tomorrow to see if it is round. That is good to know though, thank you.

After it broke it only ran for about 10 seconds, would that make a difference or no?

[beerock]

well if parts of the needle bearings went into the bottom end they could have messed up the mains etc..


usually when a rod blows, it calls for new crank, main bearings and seals just to know your starting fresh again without another mishap occuring due to the first problem

[Jeannie250R]

Take ur spark plug out and look inside the top of it........ if there is a lil piece of metal thats stuck in there than u know ur piston broke into pieces! :eek:

[TampaBoy813]

Originally posted by Jeannie250R
Take ur spark plug out and look inside the top of it........ if there is a lil piece of metal thats stuck in there than u know ur piston broke into pieces! :eek: hMmmm...a little late on the punch...:chinese:

[tazman7]

Thats what I was thinking- Thanks for the help though, it has been fixed, im just waiting for my piston to get here

[RIZZO]

Originally posted by tazman7
Thats what I was thinking- Thanks for the help though, it has been fixed, im just waiting for my piston to get here
So what did you find out....what was wrong with it to have caused this..

[Jeannie250R]

so was i right?? LOL

[MR.BIG]

read the whole thread over and you will find out your were wrong:eek2:

[Jeannie250R]

I was just messin' around, u know joking!!:eek2:

[MR.BIG]

Really:rolleyes:

[tazman7]

It ended up being a bad rod bearing that attaches to the crank. So I took it to Eric Gorr at Forward Motion and he put a new Hot Rod crank in it, and honed it out, and now I am waiting for a new piston to arrive. Then I will be good to go! Cant wait!!

I can bend my wrist a little better so as soon as I get it running im going to go race, screw the pain. haha:p