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Discussion Starter · #1 ·
Ok.. here we go

I’ve got a 2005 R6, K&N filter, block off plates, 9” delkevic exhaust with mid pipe. When I bought the bike well over a year ago it had 3 OEM ignition coils and one DENSO coil (assuming it came off a 03-04) I recently purchased a used PC3USB to get the air fuel ratio correct because I figured I would of been running lean with the mods (was the complete opposite) After install I went on dynojet website and downloaded every map available to see what felt best before going to the dyno. Put the graves slip on map on and went for a test ride.
The bike idled fine with the map and revved good. But as soon as I got outta first gear the bike would choke up super bad and felt like it was having major misfires like I was dropping two or more cylinders. This would only happen if I progressively added throttle. WOT the bike would take off like a rocket. Went back home and tried every map available and same issue. I just replaced plugs so I assumed maybe a coil was bad. Tested all 4 coils and the DENSO was extremely outta spec. For the primary is should be .2-.3 ohms and secondary 5-6k ohms. The oem ones were in range but the DENSO was 1.5 and 14K. I did a quick search and seen R1 coils were compatible, but after putting them in I had the same issue with the maps. So I tested the coils and the primary all tested at 1.5 and secondary in spec. So I thought maybe the maps were just way wrong and il go pay my shop to dyno it.

So had my bike dyno tuned with a custom map and everything went good. Was only making 90ish HP and got to 95 getting the AFR right. I was excited because all through the dyno pulls the bike was running great and sounded good. I figured it was just the maps causing the issue. I was wrong. Took the bike for a test ride out the shop and as soon as I started the problems came back. The tech rode the bike and said maybe the tps could be the issue or the coils. After reading Aton of forum pages I’ve figured out the higher resistance of the R1 coils could cause the spark plug to not fire as consistently. So I went home put all 3 good oem plugs back in with one R1 plug because it’s all I had to work with at the time. SAME ISSUE.

My main question is would I be getting this much of an issue if I only had one plug with a primary out of spec. Or could the PC3 just be bad?
I bought a set of coilspec plugs that say they are for my bike but all tested 1.5 in the primary so I tried them and same issue. I sent them all back. I’m not understanding why all aftermarket plugs for my year bike are a higher resistance in the primary. Ive ordered a set of used plugs that came off a 07 R6s because looking them up online they should test the same as my 2005. Il update when they come but before I throw more money at it I’d like to hear from someone who may have had this issue or know more about coils and what the resistance can really change.
Sorry about the book worth of reading but I could explain so much more if I felt like someone would actually ready everything lol
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Discussion Starter · #3 ·
If you unplug the PC, do you have the same issue? Did you calibrate the TPS in the PC software?
If it’s unplugged no, there is still a slight miss but nothing like what it’s doing. If I run a zero map through the PC it doesn’t do it either. It’s only when there’s serious changes made to the fuel table. And yea everytime it was ran through the dyno the throttle was zeroed out. I did it too when I was loading maps before the dyno. I just picked up my new set of oem coils so after work il give an update on what happens
 

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It'll still fire just fine with the R1 coils. You merely have shorter re-gap intervals for the spark plugs. (have to pull them more often)

The bike idled fine with the map and revved good. But as soon as I got outta first gear the bike would choke up super bad and felt like it was having major misfires like I was dropping two or more cylinders. This would only happen if I progressively added throttle. WOT the bike would take off like a rocket.
Does it just sound different alone or can you actually feel it missing?
Under light engine load, part throttle it's normal for it sound different.
Even though it sounds a little different, shouldn't really feel any different and will still respond instantly with a little more throttle added to increase engine load.

If you believe it really is having an issue, may want to reproduce it yourself for the tuner.
For your 2nd-Gen, there is a hidden AFR adjustment for the ECU.

Nice nails BTW. 😉
 

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Discussion Starter · #5 ·
So all OEM coils in and to spec. Still having the problem. Thought could be the tps then but it’s in the values on the speedo. My last guess could be battery but here’s some diag photos. d30-60 were all 0. Had 5 codes showing from working on bike. It’s a friends dash I was using so wasn’t able to clear codes and see what popped back up. If I have to il get a video of it and post it to YT to give a better idea of the bike cutting out. It’s intermittent and always below 4K or less then a quarter throttle. And is gone after I give enough throttle to get past it. Thank you for the help so far.

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From time-to-time we get some folk that don't realize that the engine sound breaking up under part-throttle is normal.

For example:
Around 6:15 mark...
around 8:03 mark...
...it can keep breaking up under part-throttle when the engine load is light enough. Seems to be more prone when the engine is making more power or are on flat land, headed downhill.
 

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Discussion Starter · #7 ·
I wouldn’t think it was an issue if it had always done it. I know it can feel like it’s lags if it’s in a low rpm/high gear situation but this is something much different. Il have to post a video to show it better. My bike is also geared 15-54. I stunt ride. So before this issue I pretty much completely got rid of what your talking about since it makes it’s torque a lot lower in the rpm’s. Hopefully after work if the weathers good il be able to link a YouTube vid to show it
 

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Discussion Starter · #8 ·
Update: Blown head gasket

Well on its way out at least. I went in to clean the injectors and after removing the throttle body I noticed some green fluid in the ports. I haven’t completely verified it yet, exhaust bubbles in radiator and it isn’t white smoking, but I’m pretty sure it is the issue. Would explain my loss of power, mis fire, loss of coolant with no other leaks
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Been on the forum for some years and can't offhand recall a confirmed case of a head gasket.

What's more likely is you spilled that coolant while disconnecting and removing the throttle body.
Coolant runs through the hoses attached to the auto-choke which is attached to the throttle body.

A "Block Test Kit" will allow you to eliminate that by testing the coolant..


Liquid water will get past the radiator to the engine when running in the rain.
 

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Discussion Starter · #10 ·
Thank you Intuit! For the help and responds. I’m not 100% sure now that you mention this. I’m sure I didn’t get coolant in there by accident after disconnecting the auto choke hoses but I did ride the bike in a tsunami worth of rain a week ago (Florida for you) and I noticed it misfiring super bad afterwards when I got home. I haven’t done a compression test but I removed my radiator cap and did see a lot of bubbles coming through when the bike was at idle and worse when I rolled on the throttle. I know how to burp the coolant system so it wasn’t just trapped air, leading me to believe it is a head gasket. Although the coolant flush was discolored. Il be dropping the oil today to check it’s color. I’ve already tore the bike down lastnight and just need to drop the motor today. Worst case for me at this point is it’s not a bad gasket and I change it for no reason. But to be honest I’d like to get in there and examine the cylinder walls anyway for cracks and wear. From everything I’ve read and watched a gasket on its way out can cause these issues and if it is bad it’s only started to go. Another option could be low compression but when I changed my plugs last I didn’t notice any oil on the electrode or any signs of oil getting passed the rings. Everything else checks out except a faulty ecu and I highly doubt that is the case.. but I’m really running out of other options.
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Good luck with the teardown and take lots of photos for us.

One hot Summer took a prior car to the carwash bay and left it idling. Made the mistake of washing the radiator by concentrating the cold spray onto a single spot. Rapidly cooled the metal, exceeding its thermal gradient spec. Week later I heard a wet sucking sound coming from the front of the vehicle after shutting the vehicle down. Radiator was sucking in air as the fluid cooled and contracted; was apparently easier than pulling in fluid from the reservoir. Dammit I ruined it LoL...
 

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Discussion Starter · #13 ·
Good luck with the teardown and take lots of photos for us.

One hot Summer took a prior car to the carwash bay and left it idling. Made the mistake of washing the radiator by concentrating the cold spray onto a single spot. Rapidly cooled the metal, exceeding its thermal gradient spec. Week later I heard a wet sucking sound coming from the front of the vehicle after shutting the vehicle down. Radiator was sucking in air as the fluid cooled and contracted; was apparently easier than pulling in fluid from the reservoir. Dammit I ruined it LoL...
Well I got rid of ATON of the carbon ( hopefully carbon and not oil ) and cleaned very meticulously. Reassembled everything to torque spec. Fresh oil filter and a few coolant flushes. Started up and idles like a dream. Did a few heat cycles burping the coolant system and sealing the gasket ( no idea if that’s needed but did it anyway ) Took the bike for a spin around the block and the hesitation is still there. Fml. I’m not upset about the job because it was much needed and there’s a noticeable gain of power. Very noticeable. But I’m at a loss for what could be causing the weird misfire feeling. Brand new plugs. New OEM coils. TPS is calibrated. Injectors, fuel pump and filter are all clean or new. There’s no vacuum leak and it has new intake boots. Air temp and pressure sensor is good. Fuel pressure regulator is dry and working. I’m going to buy a compression tester and see what my values are and will post an update. It must be a wire issue, bad tps ( even though it’s testing good with no dead spots ) or ecu but that’s unlikely. Orrrr I’m having a low compression issue. I’m really at my wits end Motor vehicle Automotive tire Rim Automotive design Automotive wheel system
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