2016 Raptor 700 rebuild

[HeWasRidinDirty]

This 700 was run out of oil. Seized the con rod to the crank....yada yada. So, I rebuilt the engine and now it will start and run for about 5 seconds and die. I replaced the fuel pump with a cheapie from ebay and it didn't change. I replaced the O-rings on the injector and still didn't change. So, the tech at the Yamaha shop said that the most likely problem is the cheapo fuel pump. I got another more expensive one and it still didn't change things. I asked him where the power to the injector comes from and he said the CDI box. But since the thing does run a little, he  ruled that out. Any thoughts?????

[MarkinAR]

CDI either runs or doesn't, normally.  Any intermittent issue with CDI is frequently once they get hot or wet.  I'm still betting it's fuel pump.  You said "more expensive one" but that doesn't always mean as good as OEM. 

this is all assuming though that it's a fuel related issue.  Could be heat shutting down a coil, compression leak on a sticky valve or head gasket...quite a bit to narrow down.  What made you go to fuel pump as the possible culprit?  Just curious.

[HeWasRidinDirty]

37 minutes ago, MarkinAR said:

CDI either runs or doesn't, normally.  Any intermittent issue with CDI is frequently once they get hot or wet.  I'm still betting it's fuel pump.  You said "more expensive one" but that doesn't always mean as good as OEM. 

this is all assuming though that it's a fuel related issue.  Could be heat shutting down a coil, compression leak on a sticky valve or head gasket...quite a bit to narrow down.  What made you go to fuel pump as the possible culprit?  Just curious.

Its kind of a long story...but..from the beginning. I never heard this bike run. When I got it the owner said he thinks it needs  a new starter. LOL. It did.....but, it needed a whole lot more. So, after doing the overhaul it would start die, start die, repeat. I had a small water leak out of the head, but I tightened down a little on it and it stopped. But, I did put a new head gasket on and no leaks so far. 

 I tested the fuel pressure. According to the manual it's supposed to be tested while the engine is running. I didn't have the right fitting to do that. But, I could test it without starting it and I did that. The pressure went up to about 45 psi (the book calls for 46) and then it would drop off. So, I figured a cheap fuel pump would tell the story. So after the fuel pump change, same thing. I adjusted the valves, just because I hadn't done it. Then the thing wouldn't crank over. Whenever it would hit the compressions stroke, it would almost stop. So I figured I did something wrong. I checked the cam timing and I was 1 tooth off and that made the changes that I made to the valves way off. I got that straightened out. Now it would crank over, but not start unless I gave it shot of ether. So, now it's getting no fuel at all. I changed to more expensive pump, and it did the same. Now, yesterday, my wife asked about these wires and this plunger looking thing hanging down. I said I didn't know what they were, so I grabbed the plunger thing and hit the starter and it fired up! And then died. It fired up a couple times, a couple of times it wouldn't. The plunger thing didn't have any effect on it. Or the other 2  wires. So, that got me thinking that there's a short or a loose wire somewhere. 

I'm not sure what these 2  things are. They weren't hooked up when it came here. 

 

Edited July 8, 2020 by HeWasRidinDirty

[MarkinAR]

Basketcases are always so much fun. There used to be a Raptor service manual in the downloads section so I'd start there and run down any loose wires and odd items hanging around. 

Sounds like you do indeed have a fuel related issue but it could be harness or ground as much as pump. I think you're real close, just one more hurdle to hear it run. 

[HeWasRidinDirty]

1 hour ago, MarkinAR said:

Basketcases are always so much fun. There used to be a Raptor service manual in the downloads section so I'd start there and run down any loose wires and odd items hanging around. 

Sounds like you do indeed have a fuel related issue but it could be harness or ground as much as pump. I think you're real close, just one more hurdle to hear it run. 

I have a service manual. I just gotta get after it and get it figgered out. The owner is starting to get antsy. It's been here about 2 months already. But, I had to send the cylinder out for re-plating, etc. Shipping these days is a crap-shoot. Mightbe 3 days..might be 3 weeks... Thanks for the input and encouragement!