Loss of power - Honda RC51 Forum : RC51 Motorcycle Forums
 
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post #1 of 10 (permalink) Old 08-15-2014, 01:50 AM Thread Starter
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Loss of power

Just wondering if anybody has had this problem, bike is an SP1, heavily modified
Engine is stock other than light clutch and junked silencer gears.

Run a full Akra system modified 2-1, Durbahn air box and snorkel.
Last time i had it dyno tested (pc2 8 years ago) it made 137.
I have just fitted a pc3 usb and a quickshifter, back to the same dyno and it has lost nearly 20 horses!

Doesn't seem to respond to afr changes so looks to be ignition related, almost like it is not getting any advance

Anybody had their ECU lose advance?

I think i am in for a few long days in the workshop substituting parts
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post #2 of 10 (permalink) Old 08-15-2014, 03:34 AM
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Originally Posted by dansp1 View Post
Just wondering if anybody has had this problem, bike is an SP1, heavily modified
Engine is stock other than light clutch and junked silencer gears.

Run a full Akra system modified 2-1, Durbahn air box and snorkel.
Last time i had it dyno tested (pc2 8 years ago) it made 137.
I have just fitted a pc3 usb and a quickshifter, back to the same dyno and it has lost nearly 20 horses!

Doesn't seem to respond to afr changes so looks to be ignition related, almost like it is not getting any advance

Anybody had their ECU lose advance?

I think i am in for a few long days in the workshop substituting parts

just to be clear dan are you talking about it losing the 20 horses over the past 8 years or do you think you have lost them in the switch to the PCIII Usb?
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post #3 of 10 (permalink) Old 08-15-2014, 05:46 AM Thread Starter
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Not exactly sure when they went missing Gaz, but it is the same with or without the power commander on it and regardless of how the afr is adjusted, whatever it is is affecting both cylinders, it rides ok, not missing which makes me wonder if the ignition side of the ecu is not working properly
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post #4 of 10 (permalink) Old 08-16-2014, 01:39 AM
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Originally Posted by dansp1 View Post
Not exactly sure when they went missing Gaz, but it is the same with or without the power commander on it and regardless of how the afr is adjusted, whatever it is is affecting both cylinders, it rides ok, not missing which makes me wonder if the ignition side of the ecu is not working properly
Did you upgrade from the PC2 or did you have a IIIr? just wondering if the ignition timing adjustment side has been left disconnected when the new one been installed as they only alter fueling, cant recall if the PC2 did ignition adjustment

and have you ridden the bike since? how does it actually feel? does it feel like its 20 horses down?
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post #5 of 10 (permalink) Old 08-16-2014, 01:52 AM Thread Starter
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Originally Posted by weegaz22 View Post
Did you upgrade from the PC2 or did you have a IIIr? just wondering if the ignition timing adjustment side has been left disconnected when the new one been installed as they only alter fueling, cant recall if the PC2 did ignition adjustment

and have you ridden the bike since? how does it actually feel? does it feel like its 20 horses down?
Went from pc2 to 3usb beacause the 3 is a better unit and i wanted the quickshifter function.
I don't think i am going to get away without carefully testing everything out, i just wondered if anybody had had a similar problem.

The bike runs ok, starts fine idles well it just feels a little anaemic, hard to say when it happened, i had almost 2 years off riding it so it may be that when i came back to it it wasn't right and i didn't notice, it may be more recently.

Part of the problem is that for the last month or two despite the hot summer it has pissed down every time i get on the bike so i haven't been wringing it's neck!
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post #6 of 10 (permalink) Old 08-16-2014, 01:58 AM
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I'd have a read of stifflers thread above this one, subsailor gave some good advice but cant remember if the pc2 did ignition adjustment so it might not be applicable to you in your situation, but it's certainly a start in the right direction.
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post #7 of 10 (permalink) Old 08-16-2014, 02:38 AM
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I know you said you went back to the same place for the dyno, but has the shop changed/upgraded their dyno machine within that 8 year time period?

Are you comparing apples to apples in terms of readouts (STD to STD or SAE to SAE numbers, etc)?

Just some food for thought to help rule out other variables that can play a part...

'06 Black/Metallic Gray RC51
-Competition Werkes FE w/
Clear Alternatives IT

'02 Silver/Black CBR 954RR
'11 Graphite Black CBR 1000RR (sold '15)
'08 Pearl Orange CBR 600RR (sold '11)
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post #8 of 10 (permalink) Old 08-16-2014, 07:44 AM
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If you still have the PCII put it back on a dyno again, if the power is back then you have an issue with the PC3.

Dyno figures vary a lot, even on the same dyno, what time of year was it dyno'd last time? It's hot now so you will see a drop in power, when it gets cold again you will see an increase. There are so many factors that influence dyno numbers they can't be relied on. The only time I take any notice of dyno numbers, is before and after mapping, then you will see accurately the increase in power. Other than already mentioned, for me dyno numbers are a waste of time, and the only purpose they serve is for bragging. That's why I never quote or post dyno numbers.

I always do a before and after run, to see the difference, otherwise you are just guessing.

What was your torque figure last time compared to this time?

Might help if you post the graphs up, to compare air temp, pressure, AFR's and torque.

PS. Was it dyno'd in the same gear both times?

Last edited by BritRC; 08-16-2014 at 07:46 AM.
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post #9 of 10 (permalink) Old 08-16-2014, 09:43 AM Thread Starter
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I have been in the workshop for the last 7 hours, i am amazed the bike was running at all!
There were so many electrical connections covered in verdigris and when i took the front plug cap off the lead pulled out of the cap and both the end of the lead and the inside of the cap were completely green.
I had some cbr600 coils and ik27 denso plugs so took the opportunity to do the conversion while i was there

I have just been out and about for a little exploratory ride and the bike feels sicker than it did before!
I am hoping that this is because now with the correct resistances on some of the sensors (even though it wasnt throwing an FI code) the fuelling is a mile off

will update when i get a chance to go back to HM racing and get it on the dyno
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post #10 of 10 (permalink) Old 08-16-2014, 09:43 PM
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Water is corrosive. This is the primary reason to apply dielectric grease to all electrical connectors and contacts.

In ares where the air has high humidity, or salt air near the coast, or even where it rains a lot, dielectric grease is the absolute cheapest insurance against electrical issues caused by moisture.
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