srx after rebuild one cylinder seems dead

T

travisgross4599

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cincinnatus,ny
I have been working on a friends srx 600. The center cylinder blew cause the power valve cable broke. we installed new: rings to to cylinders 1 and 3. new piston and rings to cylinder 2, new jug to cylinder 2, new power valve and cable cylinder 2,and total new gasket set to top end,and cleaned carbs (weren't t bad). We started it and it is only running on cylinder 1 and 3. cylinder two seem dead it is getting gas cause it starts to drip out of the header. We checked the compression and it is 120psi. I thought the coil might be bad but the new plug has great spark. we put plugs from running cylinders in it and still nothing. This really has me baffled cause it should fire with fuel, compression,and spark. Could the base be flooded? Any help would be greatly appreciated
 
travisgross4599 said:
I have been working on a friends srx 600. The center cylinder blew cause the power valve cable broke. we installed new: rings to to cylinders 1 and 3. new piston and rings to cylinder 2, new jug to cylinder 2, new power valve and cable cylinder 2,and total new gasket set to top end,and cleaned carbs (weren't t bad). We started it and it is only running on cylinder 1 and 3. cylinder two seem dead it is getting gas cause it starts to drip out of the header. We checked the compression and it is 120psi. I thought the coil might be bad but the new plug has great spark. we put plugs from running cylinders in it and still nothing. This really has me baffled cause it should fire with fuel, compression,and spark. Could the base be flooded? Any help would be greatly appreciated
Click to expand...

If you have spark, compression and fuel - about the only thing left is the crank phase.

As Mr. Viper has suggested here recently - using a long shanked screw driver, find TDC for each cylinder and mark each on the primary to a stationary pointer. Then measure with a cloth/seemstress tape ensuring the marks are equal length from one another.
 
on that sled you can swap the spark plug wires all around as they all fire at the same time to see if its spark related or coil related

you can piinch off the fuel line and see if the problem cylinder picks up indicating the float is stuck open or carb related, it could be flooded in that cylinder if gas is coming out the pipe like you describe.

or, it has a hole in the bottom of the case from the blow up....
 
I wouldn't think a hole in bottom would change compression, but would change the fuel mixture. Or maybe choke is stuck open on that carb giving too much fuel. I ran my vmax for 200 miles one time when I first got into sleds with a piece of foam over the airbox because the foam in the hood was gone. I couldn't get it to run right at all. It was getting so much fuel a brand new plug still looked brand new after 100 miles. Needless to say it ruined the cylinder by the time I figured out what it was. The point is too much fuel can be a bad thing too. Just a thought. Hope it helps. I definitely would listen to what mrviper says. He knows his stuff.
 
travisgross4599 said:
i have swapped the wires around the and 1and 3 run and 2 is still dead. if thee was a hole in base there woudlnt b a 120psi then
Click to expand...

sure there would, you build cranking or static compression above the exhaust port. It will however not build "crankcase compression" which are 2 totally differnt things.
 
tell me more about the blow up like was the piston all ruined and broken up or what?

did you pull the reed block for that cylinder and clean out the debris from blow up, petals good and still sealing to cage?

if you pinch off the fuel line going to the cylinder that wont run only, with it spitting out gas doesnt pick up, its either got a hole in bottom of case or the cranks turned.
The only reason I dont think the crank is turned because you have not mentioned it backfiring and running lean, and usually those symptoms are from crank out of phase, when it wont run at all its usually the hole in the case bottom from a pressure crack. From chunk of piston skirt or whatever goes down and it smashed into the case via the lower rod and it pops a hole in them, its pretty thin down there in the center.

remember, we cant see,hear or know the sled so can only diagnose a problem based on the information thats posted.
 
mrviper700 said:
sure there would, you build cranking or static compression above the exhaust port. It will however not build "crankcase compression" which are 2 totally differnt things.
Click to expand...


Bingo - the motor is still in the sled too I'll bet.

I suppose just a center cylinder out of phase would be unlikely.
 
Easy fixes are always good. I will plug that in the brain and maybe it will help in the future
 
I was wondering, if case had a hole in bottom, either fuel would pond under motor or fuel pump wouldn't work. Sound right? It would probably make a weird sound too from underneath? I hope I don't ever experience this.
Never mind the weird questions, super tired and can't sleep.
 
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