big bire no red line revs ?

B

bazz1397

Registered
Hello All

First post here so please bare with me on this:

I have seen a similar problem i have on this forum here:


I have had my motor ( 2000 RY ) built up using the following parts:

1397 pistons by wisco
head ported and flowed
yoshi stage 1 cams
yuasa ytx14s battery
high volume oil pump gear
billett cam chain tensioner
new cam chain

i run the motor in for 1,000 miles, took it to get set up on the dyno and it will only rev to 9,300

the graph on the dyno shows it to fade away on power then come back to life so to speak, then fade away then comes back to life, the line is up and down.

i swapped the following parts over of the same year busa that was in for a service and runs 100%

ECU
Ignition coil sticks
Spark Plugs
All Sensors
Throttle Bodies inc pump

the graph line on the dyno is staight up from the off no dips or anything until it gets to 9,300 rpm

the other post stated he had the wrong valve springs fitted, yoshimura state in the fitting instruction you dont need these as their cams are just slot in but i have re-shimmed it head to 0.20 on both sides,

power is there from 1,000 rpm to 9,300 rpm there is not a problem, it just wont hit max revs ?

i have not fitted the power commander as its not running good enough to fit it due to this problem.

i was red lining no problem before the engine rebuild,

any ideas ? as i have run out of them along with money guessing and changing parts to try and fix it.

thanks
Bazz
 
sounds like it is not getting enough fuel for what the engine can flow in air. check your fuel filter and you probably should get a better fuel pump and put the power commander on it and get it tuned. How is your A/F ratio when this is happening?
 
sorry for the late reply,

I am told the A/F reading on the dyno is spot on, the plugs are a nice light sandy brown colour, no deposits at all.

I am told by the chap who is doing the dyno work he cannot connect the power commander until the bike is running OK without it, ie not fitted.
 
do you have an aftermarket full exhaust, if so have you done the pair valve mod. Check your spark (ignition coils) and fuel delivery. those are what dictates these types of problems your having. also is the guy doing the dyno very experienced. if so the dyno should have told him what is wrong and the fuel and/or spark cannot be spot on if it is loosing power in the upper rpm only.
 
What are you running for fuel, are you running pump gas or race fuel?
 
Hi

thanks for the last two replies:

I was thinking this ( cams too far advanced ) myself ? I asked the chap who built the motor for me i wanted more power top end ( speed ) which he has told me that he has set the cams for this and i will loose out bottom and mid range now on power.

i plugged the dealer mode switch into the socket ( kept turned off ) went for a blast, the bike did this misfiring / lost power, i stopped but did not turn the engine off, then flicked the switch to see if there was a error code in the display - there was nothing, i also noticed while holding on for grim death there is no FI light flashing at all, hence no error code.

fuel wise just pump gas, i have swapped from normal unleaded 95 ron to shell v power which is 99 ron, also BP's Ultimate 102 ron and its still the same.

i am going to try and swap a bigger pump across with an adjustable regulator this coming weekend, if that dont work i will have to ask to have the cams degreed back some and try that.

spoke to a whole load of people now about this who have 1397 kits and my problem dont seem to make sense to them, they have not had any problems like this.

strange  
rock.gif


please more ideas to try incase i run out of them.

thanks
Bazz
 
(marlboroman71818 @ Apr. 24 2007,00:02) do you have an aftermarket full exhaust, if so have you done the pair valve mod. Check your spark (ignition coils) and fuel delivery. those are what dictates these types of problems your having. also is the guy doing the dyno very experienced. if so the dyno should have told him what is wrong and the fuel and/or spark cannot be spot on if it is loosing power in the upper rpm only.
Click to expand...
pair removed / yoshi RS3 full system, it went all the way into the red line before i had the motor done, with these fitted / removed.
 
got there in the end today
beerchug.gif


it turns out the ignition was too far advanced, when it was retarded it ran faultless....

thanks to all those who helped with input !

take care.

Bazz
 
Hey guys, this is starting to make me wonder. I bought a 2002 Busa about 3 weeks ago and noticed it is not hitting redline either. Stops around 9500rpms, and then the FI light starts to blink. Easy fix for the light just turn the bike off and restart. I ran some fuel system cleaner through the bike to see if maybe it had just sat around or had some carbon build up. But it still seems to be doing it. The previous (original) owner had put on a PCIII and Yoshimura RS-3 full exhaust. Am I having somewhat of the same problem as this guy? Any suggestions?
 
Well I just disconnected my PCIII and the thing is running better then ever. I can run WELL into redline with no problems and it doesnt just dump all power. Maybe that will help you all also. But now I want to find a good map to download onto my PCIII and actually take advantage of having it. Anyone got some good maps?
 
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