Hello all.

I recently purchased a 96 CBR 900 RR with 24,000 miles. The bike has the Erion paint scheme and the Erion exhaust. It is in excellent condition and runs and rides great in every way for a 16 year old bike. It cruises nice, pulls hard and runs smooth except that....

1) At around 7,000 rpm it starts to sputter and looses power like it's struggling to get enough gas. This continues through the rest of the 2500 rpm range as it struggles to get to the redline at 11,000.

I don't have close access to a certified Honda Mechanic so I took it to the local mechanic who mostly works on harleys. He suggested replacing the jets since we are in Texas and this bike came from Colorado. We went from a 120 main jet to a 125 main jet. No pilots were needed he stated since it ran good on the low end. He stated he checked the airbox and the rest of the possible causes out but found nothing. He finished by saying that it runs great... and he doubled the power...lol. I didn't say anything I just paid and left. I won't be going back!

225.00 bucks later it still has the issue.

I've looked around the internet for an answer and i'm just not finding anything specific to my bike and problem. If someone has an idea about this I certainly would appreciate some help.

Thanks.

 

And then I see this... https://cbrforum.com/forum/cbr-900rr...h-revs-128290/

I hope this isn't my problem.

 

Drain your float bowls, repeatedly. It could be sucking water into the pilot jets and not allowing gas to go through. Water can form in the tank and then get pulled into the float bowls.

You may want to try and additive like Sea Foam that will clean out your fuel system. Be careful though, some additives can eat up seals.

 

1.Check your plugs. Replace them if need. 26K...check owners manual? May need changing at 18-20k or so.

2. Check your filter, get a k&n hi flow if needed to...old filter maybe dirty...bike gasping for air.

Spark + fuel + Air must be balance.

Check fuel pump...is it working properly.

7rpm is very early to start stuttering?

Was the bike sitting for too long before you purchase it? Clean the carbs!!!

 

+1 estate
pull the plugs and read them. they will tell you the story of whats going on. if you dont know what your looking at, keep them in order and post a pic of the business ends.

if it feels like a misfire under load, it could be a plug, a plug wire, or 1 carb plugged up or running dry.

 

The bike may have had the carbs adjusted by the selling dealer if it was sold in Colorado. If a High-Altitude Adjustment was performed at a Honda dealership, there will be a vehicle emission control information update decal attached directly above the vehicle emission control decal mounted on the inside wall of the bikes storage compartment (right side?).


Original Main Jet Size was #115
Original Pilot Jet was #40

 

Checked again with my local mechanic. He stated he now remembered the Mains being a 116 and we went up to 125's...who knows really, close enough I guess.

I'll start looking at things myself here soon enough and if I need to post some pics I will.

Thanks for the replies. I was starting to get bummed out but now I have some direction.