Yamaha R1 Forum: YZF-R1 Forums banner

Ignition Coil Help/Advice Needed

52K views 28 replies 13 participants last post by  r1_rider22 
#1 · (Edited)
My '06 R1 with just under 31K miles started running like crap yesterday. It sounded like a V-twin, smelled rich, bogged under 5K RPM when hard on throttle. (It starts up without hesitation and when it's warm, it uniformly drops in RPM but at idle and accelerating from stopped sounds like a twin)



I pulled the spark plugs last night (photo at bottom). They are original stock CR9EK plugs with ~31K miles on them and they look fine. I went ahead and bought new plugs today since they're way overdue.

{Please don't flame me for being lazy on maintenance. I know plugs are supposed to be changed every 8K, and I'm overdue for valve check, yada yada.}

Maybe I was a bit premature in pulling plugs. Should I have checked for spark first? (I can easily reconnect to coils and do the "ground on motor" check). But since the plugs look fine I was thinking that it is more likely an ignition coil problem (or something worse??). But I'm not a mechanic so I figured I'd ask the R1 geniuses on this board.

I just tested the resistance:

Primary Coil Resistance spec is 1.19 - 1.61 Ohms per the Service Manual.
All of mine were at 1.8 Ohms. Is it OK to have higher resistance, just not LOWER? i.e. Do I need to replace all FOUR coils?

Secondary Coil Resistance spec is 8.5 - 11.5 K-Ohms
Mine:
#1 = 9.60
#2 = 8.35
#3 = 9.64
#4 = 9.71

I'm thinking the #2 ignition coil is providing a weak spark but I don't really know what I'm talking about. Can any of you confirm this?

In short, do these numbers indicate I need FOUR new coils or just ONE (or none)? If none, what do you think the problem is?

Thanks in advance for any help.



my stock NGK CR9EK plugs after 31k miles
 
See less See more
1
#3 ·
I put the new plugs in. Good news is my bike no longer sounds like a V-twin.:) I rode it around the block and it doesn't bog down under hard acceleration.

Bad news is, I have an erratic idle now. I set the idle at 1100'ish and it randomly jumps to 1300 or so (like one cyclinder is getting more gas or something??). I thought maybe I pinched a wire (?) near the idle screw when I put the front sprocket cover on after doing the 520 conversion a few days ago. So I took the sprocket cover off and wiggled those hoses and wires while the bike was idling. Still randomly erratic no matter where I held the wires/hoses. I played with the idle adjuster screw and adjusted EXUP cable tension. Still erratic. I'll admit the idle might have been a little rough before the whole "V-twin" issue but it wasn't THIS jumpy.

Any suggestions are appreciated.

When I have more time I'll investigate the idling issue and double check my spark plug install (how sensitive are spark plugs to "proper" torque value?? I just screwed them in hand tight and then a smidgen more). I'm thinking the problem is electrical but I'm not sure where to even start looking.

I'm just glad it runs reasonably well so I can get to school/work.

Thanks to everyone that replied.

By the way, putting the mid-fairings back on was SUCH A PITA!!!!! :nforc:and the last radiator bolt too:nforc:
 
#5 ·
oh sheet. :dundun:

yeah....my (stock) air filter....it's probably dirty as heyull. I haven't cleaned it or replaced it since I bought the bike new (Christmas 2005).
So, yeah, my air filter's got ~31K miles of debris in it.:crash

Service manual says check every 4K miles...uhhhh...I'll get right on it...
 
#9 ·
Just an update in case someone is searching.

IT WAS THE IGNITION COIL!!! (the #2 coil)

The UPS guy dropped off my new OEM part today. (A big thanks goes out to Ron Ayers for selling this part at half of what my local shop wants to charge me.) I plugged it in and started up my bike and it sounded normal for the first time since August 5th.

On August 5th, the #2 coil resistances were 1.8 Ohms for primary and 8.42 k-Ohms for secondary (then 8.35 a while later). Secondary should be between 8.5 - 11.5. Even though it was just BARELY below spec, the low resistance WAS IN FACT an indicator that this coil was going bad. I tested the #2 coil today and the secondary was down at 8.09 k-Ohms. I have been riding it every day even though it was probably ill advised. The stuttering and missing definitely got worse, which was reflected in the resistance reading today.

As a sidenote, the service manual states the primary coil resistance should be between 1.19 to 1.61 Ohms. All of mine were consistently at 1.8 Ohms. My bike runs fine. If your SECONDARY resistances are a little low, then that is the likely the problem.

Hope this helps someone down the road.

(By the way, it helps if you take a Sharpie and label your coils on the clear/yellowish plastic top part just to prevent any confusion)
 
#12 ·
ok so i have the same problem,, i changed my spark plugs last week,, and i still have the same issues, misfiring after the bike is warmed up... sounds like a v twin at times until i get to over 4k rpm, and probably running on less than 3 cylinders at times, very weak engine power under 4k rpm,

so after reading this thread i presumed it was one of my coils,,so before i go out and buy some coils on ebay, i went out and bought a voltimeter to figure out which coil or coils are bad so i can replace them, all 4 coils seems to be good. 1.4 ohm on all, and about 9.41-9.45 on all 4 coils... i am totally lost now.. can anyone point me in any other direction or what i could diagnose next??


2005 r1 with 47k miles... seemed to be running fine and all of a sudden a few weeks ago, it sounded like a vtwin and loss of power near idle.. but runs perfect after 4k rpm. replaced the plugs with stock ngk ek plugs and still have the issue after the bike gets warmed up. please help anyone
 
#23 ·
I'm having the exact same problem with my '07 R1. Just under 31k miles, I started it the other day and:

1) Sounds like a Ducati or V-Twin (louder, deeper sounding)

2) Strong smell of gasoline. I'm guessing it's because a cylinder isn't firing, just dumping fuel in and overflowing into the exhaust.

3) Rough idle, boggy and slow on the throttle.

4) Backfires a lot when decelerating with throttle closed (I only rode it once around the block once the trouble started, haven't ridden it since).

I pulled the coils and had them tested at the local Yamaha dealer. All tested ok, but the #2 coil had a small hole burned through the side of it, indicating that it's arcing. When I pulled the spark plugs, the #2 spark plug was coated with black liquid- either oil (hope not) or residual gasoline built up from not firing. I replaced the spark plugs and the problem was the same. I'll order a new coil and see if that solves it, then reply here.
 
#26 ·
Hi all - I have an 07 R1, having similar issues to both Paranoid and Adrenaline416 - however in addition to this the bike will often stall while I am running through traffic and at low revs (I suspect this may be temperature related to a degree).

The readings that I am getting from my coils are a bit opposite - on the primary resistance all 4 are out of spec (reading 2 Ohms) with the secondary measures all being nicely within spec.

I have just cleaned my air filter, 4 sparks are all iridiums in good nick, battery is less than 12 months old and holding charge well, oil changes on 6 monthly basis - clutch replaced about 18 months ago and new rotor about 12 months ago also. (generally a well maintained bike)

I am basically trying to narrow the issue down before shelling out for 4 new coils and would really welcome any advice etc.

Thanks in advance - Nooks
 

Attachments

#27 ·
I have a 99 R1 and blew the motor awhile back. Since then I bought another 2001 R1 that has been wrecked for the motor. I've switched the motors and got the bike to fire up. Problem is that I tried the next day and motor would turn but wouldn't start. It would back fire when I was done cranking the motor. And very loud at that. My coils I checked and primary reading is good, but secondary I don't get nothing. Maybe I'm doing it wrong. Any advice would be appreciated. Another thing. Fuel pump went out so I replaced it. So I put the new one in and it pressured up but the bike wouldn't fire up and number 4 cylinder filled up with gas. Advice to how I could fix that would be great also. Thanks
 
#29 ·
My '06 R1 with just under 31K miles started running like crap yesterday. It sounded like a V-twin, smelled rich, bogged under 5K RPM when hard on throttle. (It starts up without hesitation and when it's warm, it uniformly drops in RPM but at idle and accelerating from stopped sounds like a twin)



I pulled the spark plugs last night (photo at bottom). They are original stock CR9EK plugs with ~31K miles on them and they look fine. I went ahead and bought new plugs today since they're way overdue.

{Please don't flame me for being lazy on maintenance. I know plugs are supposed to be changed every 8K, and I'm overdue for valve check, yada yada.}

Maybe I was a bit premature in pulling plugs. Should I have checked for spark first? (I can easily reconnect to coils and do the "ground on motor" check). But since the plugs look fine I was thinking that it is more likely an ignition coil problem (or something worse??). But I'm not a mechanic so I figured I'd ask the R1 geniuses on this board.

I just tested the resistance:

Primary Coil Resistance spec is 1.19 - 1.61 Ohms per the Service Manual.
All of mine were at 1.8 Ohms. Is it OK to have higher resistance, just not LOWER? i.e. Do I need to replace all FOUR coils?

Secondary Coil Resistance spec is 8.5 - 11.5 K-Ohms
Mine:
#1 = 9.60
#2 = 8.35
#3 = 9.64
#4 = 9.71

I'm thinking the #2 ignition coil is providing a weak spark but I don't really know what I'm talking about. Can any of you confirm this?

In short, do these numbers indicate I need FOUR new coils or just ONE (or none)? If none, what do you think the problem is?

Thanks in advance for any help.



my stock NGK CR9EK plugs after 31k miles
My '06 R1 with just under 31K miles started running like crap yesterday. It sounded like a V-twin, smelled rich, bogged under 5K RPM when hard on throttle. (It starts up without hesitation and when it's warm, it uniformly drops in RPM but at idle and accelerating from stopped sounds like a twin)



I pulled the spark plugs last night (photo at bottom). They are original stock CR9EK plugs with ~31K miles on them and they look fine. I went ahead and bought new plugs today since they're way overdue.

{Please don't flame me for being lazy on maintenance. I know plugs are supposed to be changed every 8K, and I'm overdue for valve check, yada yada.}

Maybe I was a bit premature in pulling plugs. Should I have checked for spark first? (I can easily reconnect to coils and do the "ground on motor" check). But since the plugs look fine I was thinking that it is more likely an ignition coil problem (or something worse??). But I'm not a mechanic so I figured I'd ask the R1 geniuses on this board.

I just tested the resistance:

Primary Coil Resistance spec is 1.19 - 1.61 Ohms per the Service Manual.
All of mine were at 1.8 Ohms. Is it OK to have higher resistance, just not LOWER? i.e. Do I need to replace all FOUR coils?

Secondary Coil Resistance spec is 8.5 - 11.5 K-Ohms
Mine:
#1 = 9.60
#2 = 8.35
#3 = 9.64
#4 = 9.71

I'm thinking the #2 ignition coil is providing a weak spark but I don't really know what I'm talking about. Can any of you confirm this?

In short, do these numbers indicate I need FOUR new coils or just ONE (or none)? If none, what do you think the problem is?

Thanks in advance for any help.



my stock NGK CR9EK plugs after 31k miles
Just wanted to say thanks for all the info. This thread helped a lot. My 2006 R1 with 30k miles sounded exactly like the one in the video, however, it ran just fine, no stalling, not hesitation at any rpm. Just the unusual sound at idle. I pulled the coils and all 4 were between 9.1-9.2 ohm. The primary resistance was 1.6-1.7 ohm. I pulled the spark plugs and the gaps were all over 0.9 mm. Ordered 4 new ones from the auto store and installed them, re-installed the original coils and the bike runs as good as new again. One note, I did not have to remove any hoses or wires, just the three bolts holding the radiator. I did notice that there is not a lot of room for your hands at first, but after a while there becomes more room, I guess the hoses and what not loosen up and give you a little more room.

Liquid Spark plug Auto part Electric blue Fashion accessory
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top