LRMzx636

Ok, we have an issue with a 636 -03-04 model year making power below 4k rpm.
I don't want to hear the following

- The motor has a problem, get a new one.
- Stuntbikes never need tuning, they just run great all the time
- Aftermarket "performance" accessories dont impact performance in a negative way.

We have 2 identical bikes, same model year, similar miles.
Ninja 1 - Runs great from 1krpm to redline.
Ninja 2 - Runs great above 4k rpm to redline.

So here is what your probably thinking... just start swapping out parts to isolate the problem.
Its fuel related
Its air related.

So Ninja 2 has gotten a new (used) motor.
Changed all plugs
Changed coil packs
Changed ECU
Changed Wire harness
Changed Airbox w/filter
Changed Gas tank w/fuel pump
Changed Reg/Rect
Changed out all relays and everything attached to the subframe.

So whats left.
There is about the utmost smallest chance that 2 completely different motors are producing the same problem.

Ninja 2 was tested on the dyno and showed a lean A/F ratio between 2k and 3500 RPM. It was apparent on the dyno run that the bike needed to be tuned in this particular part of the power band.
It was recommended by a professional in the industry to add a power commander and tune the bike. He even guaranteed the problem would be resolved. Owner of Ninja 2 REFUSES to run a power commander - period.

So the only things left are.
Misc motor sensors.
Stator
Exhaust pipe
Gearing.

Ninja 1 has
GPR exhaust
46 Rear, 14 Front

Ninja 2 has
Scorpion exhaust
50 Rear, 14 Front.

We do have an additional stator. When the motor was swapped the same stator was moved from motor to motor.

So far every thread in regards to this issue has no resolution. Lets get an answer to this problem.

Possibly make a list of all the things it couldnt possibly be causing it and go from there.

Nick Apex

Air temp, map sensor, TPS?

I take it you ran a diagnostic on the bike before swapping everything? Did it spit any codes? If not grab a multimeter and give it hell. It's going to be a sensor or the feed for the sensor. Also check the vacuum lines. A clog can make a lean condition.

atl freestyle

no codes on the gauges, throttle bodies have already been swapped, thus ruling out tps.
what and where is the map sensor?
all motor sensors have been swapped cause the new motor had them on it.
swapped the stator last night and nothing.
i cant think of one piece on the bike that hasnt been swapped with a known working part.
my ecu and throttle bodies were hooked up to ninja 1 and ninja 1 rode perfect.
out of ideas. the bike is ******* cursed!!!

-SKETCHY-

no!!!! Darrick that sucks

Fuel pump? If you havn't swapped it, I have a good one (the only 636 part I have left)

-SKETCHY-

Darrick, I will send a fuel pump today.

LRMzx636

swapped tanks with fuel pumps in them.

atl freestyle

EVERY single mechanical/electrical part on the bike has been swapped with a known good part.
the bike is cursed!!!!
doomed for life
damned for life
the devil has sent his little baby jesus devils up from the depths of haities and they are running in my bike.
the bike has defied every law of humanity. i hate that ******* bike
i am probably gonna paint it a different color because the very sight of the bike makes me cringe.

-SKETCHY-

mine cut off 10+ times yesterday so I feel your pain. Checked everything too

LRMzx636

Every single part except...

Stator
Exhaust
misc engine sensors

1brownj

this leaves me about speechless after the wiring harness was swapped completely and no change did it help the other problem the no redline **** it was doing?? wtf?? you may have no choice but to use a power commander?? anybody out there have any feedback after using one the pros and cons if we go this route??

atl freestyle

already chose the route i am taking......will call everyone in about a month or less when i am riding again
https://www.stuntlife.com/forums/464...-04-636-a.html

-SKETCHY-

another 636 or a honda

atl freestyle

i did the stator last night and the exhaust after i talked to you.
all the engine sensors were swapped when the new motor was put in cause the motor came with it.

EVERYTHING HAS BEEN SWAPPED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

LRMzx636

There must be something!!!!

I refuse to believe its not fixable!

atl freestyle

and the thread slowly comes to an end with no answer.....the plot thickens.
it will be fixed, i am in the process of fixing it right now, its just gonna take a little while

marcus_136

Have you tried synched the throttle bodies?

atl freestyle

YUP!
made the bike run smooth but didnt fix my problem

EVERYTHING HAS BEEN DONE!!!!!!!

marcus_136

Then go and change your pistons

atl freestyle

i was really thinking at this point it was the powdercoating

marcus_136

Nah but seriously. I´ve been testing a couple of different 636 and they all seems to run different. One I´ve tested pulled great from 3000rpm or something like that, but under 3000 it didnt want to idle up.
And one I tried was bogging a little after it got hot and I noticed my has a slight bog as well when it is totally warmed up. I always tought it was cause the bikes didnt have their stock pipes on without tuning it correctly with a pc3.

The friend that had the 636 that bogged some after it got hot took a sponge (or whatever it is called, yellow thing you use when you wash something) and putted it into the frame where the airbox is connected to make the bike get less air and that made the bike run better, but not 100%.