Nytro rebuild problems

[jaydaniels]

Just rebuilt a nytro motor and went to fire it up with no luck. Motor spits and sputters but no go. Just looking for ideas on what could be going on. I check fire and all plugs and coils are working. Now I'm thinking it's either fuel or timing.

1. Can I check the engine timing without removing the motor? I checked timming marks in mag cover and it seems correct with number 3 at tdc. Maybe I'm off 180 deg?

2. How do you remove the fuel line from fuel rail. I can't get it off and am wondering if that's my culprit. Possibly not on far enough and no fuel getting to rail (going out on a limb with that one). The connection seems different than the one at the tank.

Any ideas would be appreciated.

 

[jaydaniels]

Well got the fuel line off. No issues there. Going to try one more time before pulling valve cover to check timming. My battery was a bit low as I cranked the motor over quite a few times to build some oil pressure before starting. Going to giv it a good charge before trying again.

 

[herndonp]

Are you getting any engine codes on your display when attempting to start it?

 

[herndonp]

Make sure wires for plug coils are on proper cylinder. Here is a diagram with color codes. #1 cylinder is on the left as viewed sitting on machine and looking over handle bars at engine.

 

[jaydaniels]

She's running. Think it was a combination of old gas, low battery and wet plugs. Took awhile for it to clean itself out.

 

[herndonp]

Great news glad it was something simple. Snows coming so sounds like you will be ready.

Pete

 

[jaydaniels]

Yeah thanks. Glad it was simple also. Can't wait to get out.

 

[Pstn head]

What caused an engine failure ? Also good to hear you got it running.

 

[jaydaniels]

I bought the machine from someone with the engine already gone. Both intake valves on the center cylinder broke off and destroyed the head and piston. I noticed 2 issues with the machine after dissassembly. First, all the headers were cracked and the center pipe had a hole in it. All this was related to a missing bolt in the muffler allowing the exhaust to flex while driving. I was initially thinking a lean condition but normally that would damage or burn an exhaust valve, not an intake. The second issue was a cracked air box cover. Looks like someone hit something that cracked the cover. It was cracked to the point that pcs of plastic where missing. I'm thinking that one of the pcs made its way into the intake on center cylinder and jammed one of the intake valves open, allowing the piston to make contact and bend the valve. Then, over time, the valve broke.