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Discussion Starter #1
Yes, I know I made a thread earlier with some issues, but thanks to a few weeks and a couple of hands, I've narrowed my problem down. I think. HELP!

2003 RC51 SP2. 9k miles. Will not hold idle unless I hold the throttle. Will run 'fine' when the throttle is held, dies when I let go (same as last thread, this didn't change) regardless of choke setting or engine temp.

New NKG Plugs (I bought 4 new ones and swapped them all around)
Does not smoke
Does not have oil burn,
No coolant in oil
Coolant is clean and has no leaks
PAIR mod, Flapper mod, Vacuum is good as far as I can tell
PC3 with map, symptoms happen whether attached or disconnected, no change in problems.

*A friend of mine said it sounded like '1.5' cylinders, or that something was 'off'

To check this, I pulled the plugs. I had both spark plugs out, attached to the coils, and cranked it over. I got blue spark from both plugs.

I put the front plug back in, by itself, cranked. It fired.

I pulled the front back out, and did the same with the rear installed on its own. It also fired.

Just to be extra sure, I grabbed a hold of each one and tested both leads with my hand. Took one for the team (twice) and blasted myself when it cranked over. :D I'm 100% sure both leads are getting healthy spark.


Ran the bike for a bit, started it different times, let it heat up. etc. When the bike dies this is the result:

front2.jpg

Front cylinder:
front1.jpg

Rear cylinder:
rear1.jpg

That is a mist of fuel by the way. Not coolant, not white smoke. I know it's hard to tell from the pic, but I assure you (almost inhaled enough today) it's atomized fuel.

Strange enough though, is the FRONT misty cylinder spark plug is a black color after running a bit (looks rich). But, the REAR spark plug is almost clean(!) but also a bit wet with fuel. BUT IT HAS SPARK. I watched for blue again, and blasted myself with the lead (a third time now :eek:)

I yanked the FPR hose off to check again, it's dry. I'm about to order it anyway, as someone suggested in the last thread. But all tests so far don't point to the FPR. (If this ends up being it I'm gonna laugh with joy)

On top of all of this, and I think this is where I'm getting somewhere, but the exhaust temps are way way off. At running temp (200-210), the front header is burning to the touch (as expected). The rear one, however, I can almost grab with my hand, it's only sort of hot. Warm almost. Which brings me back to running on 'one' cylinder. Maybe. I don't get it.

Thoughts on this update?
 

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So fuel is being injected into the air stream and brought into your cylinders but is not being ignited by spark 100% of the time or you have a stuck injector flooding out your engine? You have new spark plugs. You have spark but is it consistent spark? Have you tested your coils? Are they testing as per the manual? Check your connections and grounds in your wiring harness. Inspect your injector harness. remove injectors and have them tested or maybe have them flow tested?
This really sucks and I hope we can help you get through this.
 

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Discussion Starter #3
Thanks. Yeah I guess I'm gonna start small with the fpr. It's cheap and it's a good way to eliminate that as an issue. I was reading on here where someone had to order a new throttle body, which thankfully if I have to, I can pick up for $200-300. But I'll do that after eliminating a few other things. My pc3 is reading from the TPS fine too.

Regardless, that non ignited fuel may be coming from when the bike dies unexpectedly when the throttle kills it. Like, when I let go of it.

In any case I'm positive the front cylinder is getting a massive amount of fuel anyway. If the fpr doesn't fix it, I'll look towards the injectors.

If I had bad sensors, it would throw a code yes? Just making sure...
 

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Discussion Starter #4
So since I hate when repair threads start and are never finished, I'll bring this back from the dead to say:

IT WAS TOTALLY THE FPR

Runs great. It's been sitting for a while so now I'm working the other kinks out, but yeah, purrs like a rhinoceros.

So for the hundredth time apparently: If you have fuel problems, fuel smell, no idle, low idle, for the love of god, ANYTHING that has to do with fueling, just change the FPR. Do it. $38. partzilla.com.

'Nough said. Thanks guys! I'll update new stuff in another thread once I'm done with it.
 
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