Intermittent 3 cylinder (limp?) mode

2275 Views 9 Replies 4 Participants Last post by sdiver68, Apr 9, 2017

sdiver68

Discussion Starter · Apr 4, 2017 (Edited)

2011 ZX-10R I picked up with Flash, Dyno Tune of ECU from a reputable shop and Full Akra pipe. 2200 miles on the ODO, sold new from dealership in 2013 and mostly sat in a garage for 4 years other than occasional rides. No PCV or Bazzaz.

Background
When I picked up the bike I noticed the idle wan't great...every couple of seconds it would jump in RPM for a split second. However, it's not unusual for a tuned bike to have a rough idle and something I felt confident I could diagnose and fix with a fueling adjustment. In riding the bike was strong and smooth at all RPM's. I reached out to the tuner about the idle and he insisted it was perfect when he dropped the bike off but agreed to look at it.

Now
After an hour or so of riding it goes into limp mode and feels/sounds like 3 cylinders with SV650 like power. No Error Codes. I can 100% confirm 3 cylinder operation as soon as I get my laser temp gun back from a friend who borrowed it. When it's in this mode, idle is smooth no hunting. Turning bike off then on does not fix the problem. Bike will backfire on occasion in this mode.

What I think
1) Loose connection or corrosion of coils or harness. Recheck and clean, particularly the cylinder I believe is dropping. No signs of corrosion anywhere else, everything looks as new...

2) Spark plugs..some reports of them going out on ZX-10R. Maintenance interval is 7500 miles but they are 7 years old. While I'm there might as well for $28.

3) Injectors, double check fuel and power connections..maybe remove and have them cleaned/tested?

4) ECU Harness, double check for any pins that might be loose as a result of adding flash harness.

Any insights or advice appreciated.

Thanks!

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10Arghh

· #2 · Apr 4, 2017

Have you resistance checked the coils? That would be my first point of call.

Also definitely change out all the spark plugs....I recommend NGK Laser Iridium CR9EIA-9

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sdiver68

Discussion Starter · #3 · Apr 4, 2017

10Arghh said:
Have you resistance checked the coils? That would be my first point of call.

Also definitely change out all the spark plugs....I recommend NGK Laser Iridium CR9EIA-9

Nope but should be easy to do when I get to them. NGK Laser Iridium already in the mail!

Thank you.

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Capncalyx

· #4 · Apr 4, 2017 (Edited)

I'd say the backfire indicates unburnt fuel in one or more cylinders (Capn Obvious here!). So yea id agree that between checking the coils and a nice sparky refresh should at the very least start to sort things a bit. Also, if the bike sat that long, id run through the fuel system. Maybe send off to have injectors cleaned and clean the fuel system before installing. Could have a plugged injector from sitting. Water in gas from sitting?? Just thinking out loud here.

Edit - just re-read your post...even though he did ride it occasionally, the fuel could still pose an issue - maybe one tank of gas lasted months??

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sdiver68

Discussion Starter · #5 · Apr 4, 2017 (Edited)

Capncalyx said:
I'd say the backfire indicates unburnt fuel in one or more cylinders (Capn Obvious here!). So yea id agree that between checking the coils and a nice sparky refresh should at the very least start to sort things a bit. Also, if the bike sat that long, id run through the fuel system. Maybe send off to have injectors cleaned and clean the fuel system before installing. Could have a plugged injector from sitting. Water in gas from sitting?? Just thinking out loud here.

Edit - just re-read your post...even though he did ride it occasionally, the fuel could still pose an issue - maybe one tank of gas lasted months??

Thanks!

Likely it had bad or old gas in it at some point. I have been through about 4 tanks since I got it and only use name brand 93.

The injector cleaning has been mentioned as a possibility and the time to do it is when it's apart but thinking out loud how would that be an intermittent issue?

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sdiver68

Discussion Starter · #6 · Apr 5, 2017

A factory Kawasaki Racer and Test Rider told me he had a spark plug go out on his Gen 4 with the exact same symptoms developing over time. Hopefully replacement and cleaning of any connections I disconnect down there will solve the issue. I will probably do the injectors over next winter as it's too nice outside right now to go a couple of weeks without the bike.

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Capncalyx

· #7 · Apr 5, 2017

Sounds like a good place to start, and cheap enough and easy enough to do. Good point about the injectors, im not sure on that one so yea - go plugs first. Sounds like yer on the right track to me.

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10Arghh

· #8 · Apr 8, 2017

You can get your injectors cleaned by taking them to someone that does ultrasonic cleaning, but if it were me, I'd first buy a can of carb cleaner, and spray directly into the injector nozzles.

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tdh

· #9 · Apr 8, 2017

sdiver68 said:
A factory Kawasaki Racer and Test Rider told me he had a spark plug go out on his Gen 4 with the exact same symptoms developing over time. Hopefully replacement and cleaning of any connections I disconnect down there will solve the issue. I will probably do the injectors over next winter as it's too nice outside right now to go a couple of weeks without the bike.

Mike Taylor does injector cleaning now too.

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sdiver68

Discussion Starter · #10 · Apr 9, 2017

Spark plug I think. Changed them out, switched coils around, cleaned all cylinder specific connectors and I no longer have a gen 4 zx7r

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