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Help please. Experienced views needed.

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Old 10-11-2012, 01:04 AM
stlcbr600f4_newb's Avatar
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Default Help please. Experienced views needed.

ok here are known issues that i have...

i have a Stunt bike very noticed its been rode hard and put away wet. so i have been doing alot of research and planned work.

CCT = new one on order
intake valves out of spec( to tight .125 on one)
chain in need or replacement
exhaust leak
sync throttle bodies

performed work
brake bleed
oil change
plugs( there was old autolite cheapy in there )
coolant
throttle barrel
k&n

ok here is the situation i was experiencing a lag in power.. and loud clicking
so i took the bike apart and started going through checking clearances
all exhaust are within spec so i am good there. intake is pretty tight.
ordered a CCt and was on wait so i decided to do the plugs ..
old ones are worn to hell..
so i put the bike together in the mean time give it a run check performance
and the reaction and power difference is amazing..
bike has tons of power in reserve.
so after that i developed a 3000rpm at start up and at warm up it goes into spec. rev up you can here the buzzing in neutral at about 4-5000 rpm from the cct. but while riding under load i hear and feel a knock.. it only occured at 175 degree F or above only in gear in motion.. and clutched in motion
nothing in neutral or clutch sitting still....

personally i am thinking it maybe the exhaust leak and intake clearance
i also need to synce the throttle bodies

one i know i have to valve adjust to get proper air fuel mix.. but here is a question is the cbr f4i like a car in the respects that after a fuel system adjustment you should pull the battery and allow the ecu to re-adjust the fuel curve. and what is the possibility of a rod knock.. and what are the steps to correct the issue if it is a rod knock?
 
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Old 10-11-2012, 09:08 AM
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A exhaust leak can sound like a tick, tap or click. Most leaks dont make the sound until the engine is under load, so its hardly noticible at idle. But an exhaust leak should be really easy to find on a streetbike.

An old or improperly adjusted chain can make all kinds of unpleasant noises. Adjust or replace your chain.

Syncing throttle bodies DOES make a huge improvement in throttle response, but not engine power.

There is no way to adjust the air/fuel ratio unless you have a power commander. A/F is controlled by the computer.

Rod Knock is the Grim Reaper to an engine. Once you have true rod knock, it is not possible to repair with out a full engine teardown. The motor might run for a while but will not last long.
Oil starvation is the #1 cause for rod knock. Metal shavings or contaminated oil could also cause RK.
 
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Old 10-12-2012, 12:11 AM
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Just recieved my new chain tensioner today so let pull down begin.

i understand that you can not adjust the fuel curve. but typical fuel mapping on a complicated ECU from experience is self adjusting. according to O2 sensor reading air temp it learns the out put and adjust fuel to match factory specified
program. when reaches outside of the fuel curve threshold the Ecu default to a safe mode..

so my question is does the fuel control in the ECU react the same within this bike. cause i was wondering if that would explain some of my experience potentiallly lead to a possible spark knock.. just a theory...

exhaust leak i have located and will be performing a correction on it during this take down

i am hoping not to find a rod knock

wasnt happening till after the new plugs
 
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Old 10-12-2012, 12:45 AM
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the ecu will read the o2 sensor and make adjustments, it is a first generation fuel injected bike so no telling how many samples it takes under all conditions.
i would like to know more considering my bike has always ran rich evidently. maybe i should check my o2 sensor, its not tripping the FI but it could be bypassed
 
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