Ok, I was not driving the DS, when it happend, a friend was. The DS was running strong and hard all day (Stage 1) then my friend said it justed stopped like it was out of gas. I flipped the fuel to reserve and it was a bit hard to start. Then it did start and I heard the most ungodly noise come from the top end. Just a really loud banging noise. Like the Piston was hitting the valve. I also have quiet a bit of oil that sprayed out of my crankcase vent. I do have a K&N on it also!!

I did NOT turn it over any more until I get a chace to open it up.
Do you think it was over reved? if so how can I tell?
I belive my friend but I want to know what caused the problem on what I find broke.
What do you think??
I will pull the valve cover off and see if its visiable..
Can I tell with out pulling the head if it is a vavle??
Great, more money!!!

 

If the piston and valves met I dont think you would have got it started. Sounds like it seized on him and you have some piston damage.

 

Mine started when just one exhuast valve was bent. It had a terrible sound to it also. [img]i/expressions/face-icon-small-sad.gif[/img] Sorry for your troubles.

 

I did a simple check on my valve when I bought my DS. I just put it in TDC and took my air compressor and nozzle with rubber tip and jammed it in the spark plug hole and listened of flet for air to come out of carb or exhaust. Like a pressure test but really simple. It Works, it helped me find out that I had no clearance with my intake valves. Also make sure you have the throttle wide open.

 

When mine did the same thing last weekend it was the rod. I had alot of buildup on the oil strainer and I think it may have starved the motor for oil.

 

i feel the pain about the busted rod!!!!!!!!!! you might as well go with a bigger stroke while your in the case, drain the bottom oil plug and look for brass shavings or debri,............that will tell you if it is the rod

 

lots of brass!!!!!! in mine

 

MudStud, I have seen even stock camed ,stock valves touch the pistons. 90% of the motors I have done for people have eyebrows in the stock piston. Lots of over reving going on.

Sounds like a basic tear down and check.

J Ross

 

Man I think i'd kill myself if I was to blow my motor....Gonna try to keep those revs down then, lol. [img]i/expressions/face-icon-small-smile.gif[/img]

sorry mudstud for what happened.

 

MudStud, do you have the factory CDI on your bike? If not what rev limit are you running?