Gen 2, 2009 missing on second cylinder

bostwickenator2

bostwickenator2

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Hey all I'm having some issues with my Gen 2. Specifically I'm getting no exhaust heat from cylinder 2 (or 3 if you count from the right?). I suspected spark plugs or coils. So far I have replaced the plugs. That didn't change. I then swapped the coil from working cylinder 1 to cylinder 2 again with no change. The bike throws no trouble codes and the injector test makes a tick for each cylinder. The plug from cylinder 2 was wet with fuel when removed. Is a compression test or injector cleaning the next logical step? Maybe checking the leads to the coil second coil?

Any thoughts appreciated thanks

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Thermal of the cold pipe


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Wet second plug

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Gorescope (borescope) view of the piston head in cylinder 2. It's crusty looking and wet.
 
Ok I have been told cylinder one is rider left so I'm looking at 3 not 2. 1,2,4 work. 3 doesn't.

More data I'm getting spark on the bad cylinder with a plug hooked up externally to the coil so it's not ignition. With a cheap harbor freight compression tester I'm seeing 60psi ish on cylinder 4 (good) AND cylinder 3 (bad) if I fire it up and idle it. Pretty sure the crazy low readings are just pumping loss from almost 3 feet of rubber hose it uses. The readings are consistent between the two cylinders though so I'm tempted to rule out compression. The only idea I'm left with is a badly clogged injector which isn't atomizing.
 
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5 minutes in the ultrasonic cleaner with some hot water, GumOut, and dish soap. Gave it a quick couple of actuations with the tip in the cleaner too. Injector 3 and 4 seem indistinguishable now (Lucky I labeled them). All the copper oxide in the filters came out too. Tomorrow I'll put everything back together but swap injector 3 and 4. Fingers crossed.

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Real fine troubleshooting and nice pictures. Thanks for posting! That much gunk in the injectors?
Did you comptest at open throttle with warm engine?
Swapping leads between 1 and 2 (3 and 4) could be misleading (no pun hehe) because they are firing at different points in time. Can you see a spark while running the starter with the plug out?
 
Thanks @Phaelphon. There was a considerable amount of junk in the injectors. I don't believe that the copper oxide was actually the cause of the clog though. It seemed to be in large chunks which remained in the injector's integral filter. The copper was also in the fuel rail where the injectors seat. It took quite a while to clean that out. I can confirm it was coming from the brass in the injector. The brass appears to be a press fit part to retain the injector mechanism. If this corrosion continued I could imagine it being completely eaten away and the injector breaking. The corrosion was worse the further you got from the inlet on the fuel rail. So 1 and 2 were worse than 3 and 4. More reason why I think 3 blocking wasn't due to the copper.

Comp test was cold and at idle. I hadn't done one before and didn't know that they are normally done with open throttle. That explains the low readings but the consistency was the most important thing for me.

As for swapping around the coils. I moved the coils not the leads. So timing was not affected. All coils showed a spark when plugged into a spare (grounded) plug.

The good news:
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First start vid:
 
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Yup it was the injector in the end. I was surprised too. But the spray pattern of the injector is very important to getting good combustion. The injector can drip fuel and wet up the spark plug but without the fuel being atomized/vaporized the spark won't have enough energy to initiate combustion. At least not reliably. Once it starts missing occasionally I'm sure all the unburnt fuel in the cylinder fouls the plugs up really quickly and generally makes secondary issues.

I'm using an Infiray P2. It's very good value for money at about $220USD
 
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