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Discussion Starter #1
The bike idles , free revs but when I try to accelerate it just dies till I let off throttle. Any ideas ? I am a mechanic and have a shop manual, but I'm stumped fpr is good , has flapper mod . Will map do this ? It is an 04 sp2 low miles....
 

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Discussion Starter #3
No squirrel nest lol. Two into one pipe . It gives a two blink code for map, vacuum lines all good, tank vent clear, fresh fuel. I worked for honda dealer in early nineties, owned first hawk by on east coast, miss it now. This rc is stock except for pipe and flapper mod. I have rebuilt it from a wreck. I am very thorough, new plugs etc. I suspect map sensor or coil breakdown, asking here before I spend more $
 

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replace fuel pressure regulator, check your grounds, clean plugs, check battery.
 

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Discussion Starter #8
Hey I know this is a tough one. I've already read many of your threads before I even registered. I've been wrenching for over 30 years, I build race cars now. Have dealt with many types of injection. I'm not a novice...but welcome fresh input as I am new to this rc51 thing. I ride a 98 cbr1100xx blackbird..
 

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The bike idles , free revs but when I try to accelerate it just dies till I let off throttle. Any ideas ? I am a mechanic and have a shop manual, but I'm stumped fpr is good , has flapper mod . Will map do this ? It is an 04 sp2 low miles....
Interestingly enough, my VFR800 started sporadically acting this way yesterday.
Would idle just fine, but would sputter and die if the throttle was rotated off idle.
After a moment, it would resume running just fine.
Will be troubleshooting later this weekend.
 

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Discussion Starter #12
Update... New fuel pressure regulator installed, busy checking wire harness connection s, will look at sidestand and clutch switches, and relays. Harness has no visible damage but could still have problem. It's rainy here so unlikely to test till weather breaks...Thanks for input !
 

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easy job as long as You have got proper tools to check it and using brain.exe. before You will change presurre regulator - just unplug vaccum pipe from it ( and keepit closed-squeez it using pliers) when You undo vaccum pipe from pressure regulator You should notice rising rpms at idle - leave it for a while and open a thtotle few times - check if vaccum connection port on pressure valve is dry.
wet vaccum connection port or/and no change inprms are symptoms of bad pressure regulator, but to confirm that Your problem is fuel related You could make fuel rail pressure test (about 42PSI on idle and rising a little when WOT) and injector test for operation and leak, You can make it using cheap tools - fuel pressure gauge and injector tester - about 50-70 USD and You can start Your diagnosis.
It is strange that You haven't got it already - You are a mechanic guy - aren't You?
I'm a mechanic guy too - and I can't live ifI'm not able to make any test because I'm depending fromsomebody - that's why I have gotmy own tools - from incandescent light probe, to TEXA bike dianostic computer and fast PICOSCOPE
anyway
first - You must adress the problem -is it fuel or ignition related issue.

then use proper diagnostic algos/procedures and tools to find and then confirm results (talking about procedures I'm not thinking about service manual problem rsolving algos - it is waste of time and written with ingorance of inteligence of the readers)
 

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Discussion Starter #15
Thanks for input mr zyjek. I found a bad connection 4 map sensor with ohm meter. I bought this bike as a basket case, have 2 throttle bodies, 2 fuel pump assemblies etc. First fpr was leaking at vacum port. I have aquired a peak voltage adaptor to check coils, hope to work on it this wknd ...
 

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Discussion Starter #18
How could stand switch affect it only under load or "atempted" acceleration? I havnt had time to f**k with it ; (
 

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clutch and sidestand can't cause the behavior you describe. the side stand will just shut the bike off and the clutch won't do anything

the symptoms are in line with either low fuel pressure (did you test your pump?) or a plugged intake or exhaust (was the bike stored where animals could pack it full of stuff?)
 
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