RC51 power drop. need help

Calvin71 · #1 (**permalink**) 10-10-2008, 01:12 PM

I have a 2001 RC51, i will try to explain this the best i can, sometimes when i go to pull the throtle the bike cuts out for a second, the returns. You know when you turn on the ac in your car and the car cuts out or clicks down my bike dose this, i replaced the plugs oil, and not sure what the heck is going on, or if all the rc51 do this. im hoping its nothing bad, and can be fixed. any help thanks.

DesperateSP2 · #2 (**permalink**) 10-10-2008, 01:53 PM

More input is needed: does the FI lights come on, is the bike stock or does it have any mods, how many miles does it have, does this happen in some precise occasions etc.
Could be an electrical malady, an alarm playing tricks or even a clogged fuel filter.
But as I said more input is needed

Calvin71 · #3 (**permalink**) 10-11-2008, 10:32 PM

Thanks for the reply.

I've got 22,000 miles on the bike, no indicator lights on the dash to tell me something is going on. This only happens sporadically. As far as modifications, I have no power commander, I've done the flapper valve mod, and it has aftermarket exhaust.

Other than this, the bike runs very strong.

Redstar · #4 (**permalink**) 10-12-2008, 01:04 AM

Well most likely thats your problem right there, get a power commander with a custom map or a correct map and that should solve the problem. Your stock ECU is used to having a stock exhaust, now that you have a better flowing aftermarket exhaust you just changed a variable with your fueling, hopefully that helps. I always suggest that to people, aftermarket exhaust with a power commander with a good map because IMO you wont see the full benifits of an aftermarket exhaust with out a PC.

Calvin71 · #5 (**permalink**) 10-12-2008, 02:37 AM

Thanks for the info. One last question...Do you have any recommendations for a good power commander?

DesperateSP2 · #6 (**permalink**) 10-12-2008, 07:04 AM

These bikes, especially the ones build from 2004 have a noticeable "power dip" at around 4000 rpm to comply with emission and noise regulations. Maybe it's the problem you are trying to solve?

On mine (2003 model) I noticed that there are many small dips all across the range (notoceable when you are on half throttle) that a decent exhaust and a PC will help fill in.
As for a Power Commander get a PC3USB from Dan Kyle: Kyle Racing - Roadracing Motorcycles . I cannot think of a better place to shop for it.

hondaman4life · #7 (**permalink**) 10-12-2008, 04:20 PM

Hi guys, my 51 has a very similar problem also. When I hit a bump in the road for instance or, ride over railroad tracks etc.... the FI light comes on but it's dim. The power cuts out but when the FI light goes out the power kicks back in. I'm very concerned because I don't want to be in a nice set of twisties and have this happen causing my rear tire to break away leading to disaster.

theMadWelder · #8 (**permalink**) 10-12-2008, 04:58 PM

Quote:

Originally Posted by hondaman4life

Hi guys, my 51 has a very similar problem also. When I hit a bump in the road for instance or, ride over railroad tracks etc.... the FI light comes on but it's dim. The power cuts out but when the FI light goes out the power kicks back in. I'm very concerned because I don't want to be in a nice set of twisties and have this happen causing my rear tire to break away leading to disaster.

This happend to me early on, I had a relay in the back that was mounted upside down.
Yours may be as simple as a loose battery connection.
Just my guess, please get better advice than mine.

DesperateSP2 · #9 (**permalink**) 10-12-2008, 05:18 PM

Quote:

Originally Posted by hondaman4life

Hi guys, my 51 has a very similar problem also. When I hit a bump in the road for instance or, ride over railroad tracks etc.... the FI light comes on but it's dim. The power cuts out but when the FI light goes out the power kicks back in. I'm very concerned because I don't want to be in a nice set of twisties and have this happen causing my rear tire to break away leading to disaster.

Seconded that, it's a bad connection somewhere. I had that happening twice (see another post...

): first time it was a faulty alarm and second time it was a knackered battery terminal. Take off the tail unit and double check all connections, especially the one leading to the charge protection fuse on the battery cover. The cable will become too stiff and will move the fuse around, causing a drop in electrical power and therefore power.
Let us know.

stuckinNC · #10 (**permalink**) 10-12-2008, 07:29 PM

Hondaman I had that same problem 2 years ago at VIR, but only through the esses. turned out my tank was shifting just enough throughing it back and forth through turn six that I was cutting through my power commander harness. I just had to fixed the 2 wires that got messed up and rerouted it.

fiddlerofbeans · #11 (**permalink**) 10-13-2008, 06:29 AM

I had a similar problem with my RC. It would cut out when I accelerated. It ended up being a loose plug on the EFI box mounted on the sub frame. Hope you figure it out.

Hung · #12 (**permalink**) 10-13-2008, 08:36 AM

I had same problem, I had whole bike wireing harness repackage, I used 3 M to isolate the harness, then it good till now.