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After replacing cylinder head, bike won't start - F4i

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Old 09-29-2010, 12:41 AM
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Default After replacing cylinder head, bike won't start - F4i

Well after weeks of ripping out the engine, and getting a spark plug hole time-cert, apparently I did something wrong putting it all back together.

So the bike primes perfectly fine, and all the electrical stuff seems to be good. But it won't start unless I give it full throttle; and when it fires it's doesn't sound right, and it's a very low idle. And when I close the throttle, it dies. Also, when it does start, I smell almost a slight burning smell (it might just be excess fuel dripping out since I'm at full throttle).

Any ideas on what could be the problem? Does it sound like a timing issue, because that's what I'm thinking. I aligned everything according to the service manual, with TDC at the crank and the cam markings. I suppose it's possible it moved a bit. Could it be something with the spark plugs? Or a hose that didn't get connected? I really don't know where to start. Any help would be greatly appreciated.
 
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Old 09-29-2010, 02:45 AM
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It sounds like a timing/spark plug issue. You sure the ignition coils are in the right cylinders and theyre firing in the right order?
 
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Old 09-29-2010, 04:21 PM
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You mean the rubber ignition coils? Or are you talking about the electrical connectors to them? I'm pretty sure they are in the right order, I can recheck.
 
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Old 09-29-2010, 04:58 PM
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yeah the wires going to the coils that deliver the spark. If those aren't on in the right order the cylinders wont fire in the right order. Is there any unusual shaking or vibrating when the bikes in gear?
 
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Old 09-29-2010, 10:08 PM
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Originally Posted by nickp123 View Post
yeah the wires going to the coils that deliver the spark. If those aren't on in the right order the cylinders wont fire in the right order. Is there any unusual shaking or vibrating when the bikes in gear?
I'm pretty sure the coil connectors are on in the right order. If you are sitting on the bike, the #1 plug should be on the far left cylinder, correct? As far as shaking or vibrating, I'm just simply trying to start the bike and get it to idle in neutral. So I didn't notice any of that.

From what I described in my initial post, does it sound like the timing could be messed up? The bike won't start at all, unless I give it FULL throttle, and hold it. The engine will turn on, and be at a very low RPM, then if I let off the throttle at all, it dies instantly. And the engine doesn't sound quite right, either.

Any other ideas on what could be the problem, before I check the timing? Thanks for the help!
 
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Old 09-29-2010, 10:36 PM
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Throttle position sensor? Would affect the engine timing and fuel mix which could cause symptoms like that I think
 
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Old 09-30-2010, 01:33 AM
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definately check the timing. the tps would throw a code but it shouldnt prevent you from starting the bike like that. If the timings off or it is a misfire could not fire or start until theres a lot of gas in there to ignite like when you give it full throttle, could also explain why it smells like its running rich.
 
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Old 09-30-2010, 01:37 AM
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check your vaccum lines too. a rough or low idle might mean its not getting enough air and then the fuel wouldnt be completely burned either resulting in that smell. but all could relate to timing or tps sensor once its running like kuroshio said actually
 

Last edited by nickp123; 09-30-2010 at 01:42 AM.
  #9  
Old 09-30-2010, 03:46 AM
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Originally Posted by nickp123 View Post
check your vaccum lines too. a rough or low idle might mean its not getting enough air and then the fuel wouldnt be completely burned either resulting in that smell. but all could relate to timing or tps sensor once its running like kuroshio said actually
Thanks for the reply's. You know the bundle of 3 hoses that are taped together near the bottom of the bike? Well after putting the engine back in, there was one of those hoses that for some reason I didn't label. And I still don't know where it goes. I kinda doubt that's the reason the bike isn't starting though. I mean I would think they are just drains.

Also I do have a power commander installed. Should I try hooking up the stock connectors? Thanks for the help
 
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Old 09-30-2010, 01:25 PM
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if my bike wasnt in a different state id be glad to go look and see but maybe someone else could. if its a drain than i doubt it but if its something else and something isn't recirculating like it should be than there you go. Stock connectors couldnt hurt but doesnt the pc automatically adjust the a/f ratio or does it only adjust it to the map that you have running? if so maybe you need to change the map. did you do anything to the intake, exhaust, or heads that would cause a change in the a/f ratio?
 

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