Jump to content
CBR1100XX.org Forum

Problems reving past 7000rpm


clutchburningracing

Recommended Posts

Is the FI light on?

Ensure the FI light is working. IIRC it should be illuminated when you first turn the bike on.

I know it sounds like a stupid question. But hey, one of my secret powers is an uncanny ability to notice the obvious.

Link to comment
Share on other sites

Are all air/air filter passages open and clean? A blocked air filter could cause similar problems...Are you running a stock or K&N fliter?

Link to comment
Share on other sites

Fiberglass tank- removed the cap=no change

2nd set of new plugs= same

looped the FI for trouble codes=same

not running an air filter

aftermarket big fuel pump with pressure guage and regulater 50psi at idle does drop a little when reved quick 46 or 47psi

replace the cam pulse pick up and gen=same

tried with air filter=same

checked timing on the cams and with a timing light=same

changed ecu= same

aaaaaaaaaaaaaaaaahhhhhhhhhhhhhh!!!!!!!!!!!!!!!!!!!!

Link to comment
Share on other sites

Fiberglass tank- removed the cap=no change

2nd set of new plugs= same

looped the FI for trouble codes=same

not running an air filter

aftermarket big fuel pump with pressure guage and regulater 50psi at idle does drop a little when reved quick 46 or 47psi

replace the cam pulse pick up and gen=same

tried with air filter=same

checked timing on the cams and with a timing light=same

changed ecu= same

aaaaaaaaaaaaaaaaahhhhhhhhhhhhhh!!!!!!!!!!!!!!!!!!!!

Throttle cable too short?

Looks like you covered alot of ground, That's all I could come up with :icon_redface:

Link to comment
Share on other sites

I'm speculating here, but I wonder if disconnecting the knock sensor would change anything.

No. Or highly unlikely.

Fiberglass tank? Aftermarket pump?

Lets flesh this story out. There's more here than a simple "breaking up at 7 grand."

I agree, has it ever worked right?

Link to comment
Share on other sites

put different injectors in it, ran rich but still the same

pulled the turbo off running just motor. in the process of tuning the bike to set up the spray. motor still has the turbo 9:1 pistons, really i changed nothing just removed the turbo. the a/f fuel is fine right up to 7000 then goes all over the place. it kinda acts like it is hitting the rev limiter, just not as pronounced. i disconnected both power commanders and tried just the ecu-same. valves not closing at that rpm?? pistons in backwards????? cams out of time?? ecu not advancing timing??? i am almost to the point of pulling the motor out and starting over. :icon_wall: :icon_doh:

Link to comment
Share on other sites

Pull the valve cover and check that the cams are in right and valve lash is correct. Do a compression check.

Would knock if the pistons are in backwards at idle, pin offset.

Put a timing light on and make sure it is advancing. Should be spot on at idle, and move as you accel. would need a degreed mark for max adv.

Check plug gap, to small won't accel. But starts nice.

Change fuel and fuel filter.

Check the exhaust temp with ir temp gun.

Sound like fuel injectors pluged. Take out and spray backwards with air and carb cleaner, and keep off the orings. Will swell. If they doo let dry and oil to replace.

Make sure that fuel flows out the fuel line fast enough and does not slow. With the fuel pressure good that does ot sould like it is the problem, but should keep droping.

Put other injectors back in. Go back to what worked.

If you are doing this you should keep a book and log each change. Only do one thing at a time. You need egt and afr readings to know.

Just some things off the top of my head.

Bet you have plugs wired wrong, check that the positive is going to the right side of the coil. Check plugs are firing, each one.

check the resistance of the plug wires

check the wire is pluged on to the plug,,,,some need the screw removed to connect

Check the plugs are correct.

Link to comment
Share on other sites

This does not sound like a fuel problem. Have you tried changing the coils? When a coil starts to go bad, it will not produce a hot enough spark for higher RPM. Also, check all wiring related to ignition. You may have a short somewhere.

Good luck finding the problem.

Link to comment
Share on other sites

how would I check the coils on a meter? valves-would a bad spring be the problem?

Or if your running a lot of boost you can hang a intake valve open.

Link to comment
Share on other sites

how would I check the coils on a meter? valves-would a bad spring be the problem?

Or if your running a lot of boost you can hang a intake valve open.

He cant be running boost if his turbo is in Indiana.

:icon_whistle:

Link to comment
Share on other sites

how would I check the coils on a meter? valves-would a bad spring be the problem?

ohm meter and resistance, book will tell correct number, i think 1.2 ohms off the top of my head

Link to comment
Share on other sites

how would I check the coils on a meter? valves-would a bad spring be the problem?

Or if your running a lot of boost you can hang a intake valve open.

He cant be running boost if his turbo is in Indiana.

:icon_whistle:

Josh did you buy that too?

Link to comment
Share on other sites

I think it is muffler bearing ,,,,,,,,

Obviously lots of things has been modded on the bike ,trying to troubleshoot it over the Internet might not be easy,,,,,,,,

I understand it run stock ecu with turbo,so I guess fuel pressure regulator has been changed to rising rate regulator.Stock is reference type.A/F might go just too rich in high rpms,anyway, what is fuel pressure in stock motor/fuel system.? 50 sounds kind of high,it suppose to drop with engine running under vacum conditions ( like high rpm/small throttle openings)

I would start here,just to cover the most obvious areas.

Link to comment
Share on other sites

how would I check the coils on a meter? valves-would a bad spring be the problem?

ohm meter and resistance, book will tell correct number, i think 1.2 ohms off the top of my head

Yah, What he said. Sorry I'm late.

Link to comment
Share on other sites

Might be a long shot,......check your battery and charging system. I just had the exact same symptoms on my Yamaha SRX600. @low rpm the battery could keep up with the charging system but at higher rpm it couldn`t and the voltage would climb as the regulator couldn`t keep up. Blew two headlights and a turn signal before the lightbulb in MY head turned on. Replaced the battery and all was good.

Link to comment
Share on other sites

I just went out and got a years supply of connectors and solder!!!

This whole time checking and replacing everything, running my self CRAZY over this gremlin. I almost pulled the motor to check the head.

I FINALLY FOUND IT!!!!!!!!! :icon_clap: :icon_clap:

A 1 1/2 inch strand of wire with a connecter on one end that was on the ground side of the fuel pump was loosing connection when the bike started to rev high. Two strands of copper were holding the connection. Makes sense why the air/fuel went crazy!! Man I feel like a DUMB AZZZZZZ!!!!!!

Thanks to everyone that gave input on my gremlin hunting adventure.

Link to comment
Share on other sites

I just went out and got a years supply of connectors and solder!!!

This whole time checking and replacing everything, running my self CRAZY over this gremlin. I almost pulled the motor to check the head.

I FINALLY FOUND IT!!!!!!!!! :icon_clap: :icon_clap:

A 1 1/2 inch strand of wire with a connecter on one end that was on the ground side of the fuel pump was loosing connection when the bike started to rev high. Two strands of copper were holding the connection. Makes sense why the air/fuel went crazy!! Man I feel like a DUMB AZZZZZZ!!!!!!

Thanks to everyone that gave input on my gremlin hunting adventure.

Yeah that was my nexxt guess :icon_shifty:

Glad you found it!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

Terms of Use