[Snowman22]

Hello, was just hoping someone would know what might cause my CBR 929RR to sputters and buck at any more than 1/4 throttle. Power loss is extremely obvious at all times but even when I'm over 3k RPM there is no ability to give full throttle or even half or it starts sputtering very bad.. Bike was wrecked and am still working on getting everything replaced so I currently don't have a speedo so I can't see if it's throwing any codes. Any help would be appreciated thank you!

 

[oldbastard]

Without knowing more,my first reaction would be that it's a fuelling issue. Usual suspect is fuel pump or fuel pressure reg. The second can be quick checked by pulling off the line to vacuum when it's idling. Any fuel coming out = bad regulator.

 

[copsrpigs]

I assume it was on its side since it’s been wrecked.
Put some plugs in it.

 

[COBRA90GT]

Any updates Snowman? Pulling the plugs to inspect them (post up pics if you can) is a good idea but yeah definitely sounds more like a fueling issue IMHO.

Was the bike sitting in storage for a long time after it was wrecked or something?
The fuel "sock" filter/strainer in the tank (and related lines upstream or even the rail/injectors) could be partially blocked, etc preventing proper flow - what's the inside of the tank look like ?

 

[BigdaddyPaz]

this sounds like a FPR (fuel pressure regulator) issue. i seen a 03' 954 do this, ran great in lower RPMs then hit about 8 k rpms then bogged out. its an easy and cheap fix.

 

[salty_scav]

I had similar @idle+1/4_throttle issue along with a noticeable stumble that came on at 7-8k++RPM; there is one vacuum line attached to the FPR running towards the engine and it splits at a T-junction into 2 more lines that attach at the intake plenums of the #1 and #4 cylinders. I found liquid fuel in both vacuum lines which denotes a faulty diaphragm inside the FPR. I replaced the FPR and that resolved the idle/throttle issue. The high RPM stumble remained, so I inspected All Plugs+CoilCaps<All 4 plugs were in spec., Resistance for Coils in spec. but the #1 & #4 CoilCaps had oxidation/rust on the spring-retention clips inside of the boots that degraded them beyond their ability to spring back into place and retain a solid connection to the spark plugs. Taking the boots off is a bit of a tight spot, and this a good example of where dielectric grease was helpful in reassembly and can prevent the type of oxidation that obviously affected these parts. I replaced them with a set of used CoilCaps from a parts yard that were in much better condition and the high RPM stumble was resolved. Best of Luck~