help my Power Commander is down K O need a used one

alpinestarsrc51 · 02-10-2009, 12:53 PM

i have had a power commander IIIr on my bike and well it has stopped working and my bike is running like **** but i dont have the money for a new one right now and thay stopped making the IIIr so if you have one sitting around from having a rc51 you sold or something any help would be good and since the temps 75 today its killing me since its not running right at all i dont wanna ride it and something happen thanks

muddysteel · 02-10-2009, 2:58 PM

Shouldn't hurt anything - but why not just disconnect it if you want to ride?

alpinestarsrc51 · 02-10-2009, 4:46 PM

i have an with the sprockets i have and other add ons its back firing on decompression like shoots flams out the pipes very easly and dont wanna bend a valve.

sheepofblue · 02-10-2009, 5:08 PM

Almost sounds like you have other issues also.

b.miller123 · 02-11-2009, 1:00 AM

Um, pull the PC off and use the clutch and brakes instead of engine braking everywhere you go?

58cycle has had PC3r's on clearance forever, they are like $167 or something, if you need one that bad. You might be able to find a used PC3 usb for around $150 -$200, and you can look on eBay and find used PC2 and PC3's for fairly cheap, but your still getting a used item. I would make sure that you really need a new one first.

Have you tried to hook the PC up to a computer yet?

What exhaust do you have?

lanbrown · 02-11-2009, 1:04 AM

Sprockets have no impact on how the engine runs. What other "add-ons" do you have?

alpinestarsrc51 · 02-11-2009, 1:16 AM

Quote:

Originally Posted by lanbrown

Sprockets have no impact on how the engine runs. What other "add-ons" do you have?

it does when you are slowing down coming into the corners i can ride the bike easy fine but cant run the bike like i want to or like it was built to do. i have ported and polished head k&n air filters flapper mod ,stock cans cut in half an re-poprivited. thats it for mods that have to deal with the motor.

lanbrown · 02-11-2009, 7:22 PM

Sprockets will not alter how the engine runs.

If you put a different read-end on a car; a 4:10 rather than 3.73 and then the care sputters, was it the rear-end? The answer is no. That is what the sprockets are to a bike.

You have other issues.

alpinestarsrc51 · 02-11-2009, 7:46 PM

didnt need to be told how my bike should run i know that i build car motors for drag racing thats why i got no money ppl are not racing any much since they are saving money.

i know alot more then you think if you change your gearing and you are coming into a corner and you down shift that down shifts puts you at a higher rpm then it would with the stock gearing i am not talking about the bike. and the rc51 bikes run rough and have bad decompression braking in stock form the power commander smooths it all out.

lanbrown · 02-11-2009, 8:39 PM

Quote:

Originally Posted by alpinestarsrc51

didnt need to be told how my bike should run i know that i build car motors for drag racing thats why i got no money ppl are not racing any much since they are saving money.

i know alot more then you think if you change your gearing and you are coming into a corner and you down shift that down shifts puts you at a higher rpm then it would with the stock gearing i am not talking about the bike. and the rc51 bikes run rough and have bad decompression braking in stock form the power commander smooths it all out.

Of course the engine revs higher, but the engine still runs the same now doesn't it? Then what was the point of mentioning the sprockets in your post?

Quote:

Originally Posted by alpinestarsrc51

i have an with the sprockets i have and other add ons its back firing on decompression like shoots flams out the pipes very easly and dont wanna bend a valve.

alpinestarsrc51 · 02-11-2009, 9:36 PM

with the rpms up higher when you let of the back pressure is also higher pointless convo you are not getting it.

lanbrown · 02-11-2009, 10:02 PM

Wrong, the max RPM is just that. 9,500 RPM is 9,500 RPM no matter what your gearing is.

Tell you what, I'm done and I'm sure others feel the same. So, you just got what you asked for; no help. Enjoy it.

muddysteel · 02-12-2009, 2:04 AM

Quote:

Originally Posted by lanbrown

Wrong, the max RPM is just that. 9,500 RPM is 9,500 RPM no matter what your gearing is.

Tell you what, I'm done and I'm sure others feel the same. So, you just got what you asked for; no help. Enjoy it.

alpinestarsrc51 · 02-12-2009, 2:37 AM

i was not saying it moves up the max rpm i am saying that if you are in 5th coming into the corner you brake and down shift to third to gas through the corner that when you first let out with out the power commander the air to fuil mix is not right= in tune for whats been done to the bike it makes the motor decompression rough to where it pops that can bend a valve for one and it can lock up the back tire and my bike never did this with the power commander working and since have plugs in my friends rc51 power commander with my map on it and it runs right i am not trying to know it all but i knew what was working before the power commander went bad and how it runs with one working.

muddysteel · 02-12-2009, 1:55 PM

Well, seems you solved your problem - and unplugging the PC would've determined right away if it was the PC or not..

You seem to be confusing ignition timing with valve timing. While the two things can show up in a similar fashion (fire out the exhaust), incorrect valve timing shows up right away (like, the bike barely starts, if at all).. So, if the bike was running before, valve timing is a secondary diagnostic - ignition is primary.. Which, obviously, is what the PC affects..

Backfiring due to ignition problems won't cause a bent valve - it might punch a hole in something (like the top of a piston).

"motor decompression rough to where it pops" won't bend a valve - over-revving the engine with engine braking can - that is, if the valves are not properly timed. Perhaps this is what you meant..