Rear Cylinder not Firing - SV650.org

05-02-13, 06:35 PM

Coming home from work tonight the rear cylinder just suddenly stopped. Smells like there is plenty if fuel going in so I guess I need to check out plugs and coils etc. Can I just swap the front coil leads to the rear to see if the rear runs or would the spark not fire at the right time for this to work? Any tips for getting into the coil? Is it an air box off job? It all seems very tight down there and I have left the Haynes manual elsewhere.

Sid Squid · 05-02-13, 06:49 PM

Bike, model?

05-02-13, 07:17 PM

Ohh it does tend to help!! Sorry it's an 08 SV650

jambo · 05-02-13, 09:09 PM

How have you determined that it's the rear that's cutting out?

Directly swapping the ht leads over from front to rear wouldn't get that cylinder running in the correct timing, as the signals to front and rear coils are timed differently. I'd pull the most accessible plug from each cylinder, ground it on the frame and check if you get a spark when the motor's turning.

Jambo
Sent from my thingie

05-02-13, 09:32 PM

The rear pipe is cold and it runs the same with the rear HT lead off so it appears to be the rear that's out. I Shall check for a spark when I get a chance to have a look.

jambo · 05-02-13, 10:00 PM

Is there an FI error message on the dash when it's running?

Jambo
Sent from my thingie

05-02-13, 10:33 PM

Nope nothing. I took the rear plug out and it was a bit black. Cleaned it up
But made no difference. Didnt have time to do anything else tonight. Bike has been running fine with no issues. Shall pick up some new plugs tomorrow and change them then go from there. Last time I had an engine drop a cylinder it was a defective valve seat in my civic. I hope it's nothing to serious.

06-02-13, 12:11 PM

Whats the best method to get access to the coil pack? Do i need to take the tank and airbox off?

Sid Squid · 06-02-13, 02:27 PM

Clarification: K8, twin plug, yes? However thus far you've only referred to 'the plug', have you made certain both plugs are connected correctly? If either plug doesn't fire, it's partner won't either.

Make sure of the connections first, both LT and both plug caps. If all seems well, take both plugs from each cylinder and fit them to the other, does the problem move from one cylinder to the other?

06-02-13, 03:24 PM

There is definitely only one plug, just noticed my typo above its on an 07 reg. I am going to buy some new plugs on the way home from work tonight and change them over. I shall see what else i can change over between the two cylinders whilst i am at it. I think i have my multimeter kicking about somewhere so shall try and do some other checks.

05-02-13, 06:35 PM	#1
gt900uk Guest Posts: n/a	Rear Cylinder not Firing Coming home from work tonight the rear cylinder just suddenly stopped. Smells like there is plenty if fuel going in so I guess I need to check out plugs and coils etc. Can I just swap the front coil leads to the rear to see if the rear runs or would the spark not fire at the right time for this to work? Any tips for getting into the coil? Is it an air box off job? It all seems very tight down there and I have left the Haynes manual elsewhere.

05-02-13, 06:49 PM	#2
Sid Squid No, I don't lend tools. Mega Poster Join Date: Jul 2003 Location: Skunk Works, Nth London Posts: 8,680	Re: Rear Cylinder not Firing Bike, model? __________________ If an SV650 has a flat tyre in the forest and no-one is there to blow it up, how long will it be 'til someone posts that the reg/rec is duff and the world will end unless a CBR unit is fitted? A little bit of knowledge = a dangerous thing. "a deathless anthem of nuclear-strength romantic angst"

05-02-13, 07:17 PM	#3
gt900uk Guest Posts: n/a	Re: Rear Cylinder not Firing Ohh it does tend to help!! Sorry it's an 08 SV650

05-02-13, 09:09 PM	#4
jambo Member Mega Poster Join Date: Aug 2003 Location: Croydonia Posts: 5,376	How have you determined that it's the rear that's cutting out? Directly swapping the ht leads over from front to rear wouldn't get that cylinder running in the correct timing, as the signals to front and rear coils are timed differently. I'd pull the most accessible plug from each cylinder, ground it on the frame and check if you get a spark when the motor's turning. Jambo Sent from my thingie __________________ Modern motorcycles are bloody brilliant, enjoy it while we can

05-02-13, 09:32 PM	#5
gt900uk Guest Posts: n/a	Re: Rear Cylinder not Firing The rear pipe is cold and it runs the same with the rear HT lead off so it appears to be the rear that's out. I Shall check for a spark when I get a chance to have a look.

05-02-13, 10:00 PM	#6
jambo Member Mega Poster Join Date: Aug 2003 Location: Croydonia Posts: 5,376	Is there an FI error message on the dash when it's running? Jambo Sent from my thingie __________________ Modern motorcycles are bloody brilliant, enjoy it while we can

05-02-13, 10:33 PM	#7
gt900uk Guest Posts: n/a	Re: Rear Cylinder not Firing Nope nothing. I took the rear plug out and it was a bit black. Cleaned it up But made no difference. Didnt have time to do anything else tonight. Bike has been running fine with no issues. Shall pick up some new plugs tomorrow and change them then go from there. Last time I had an engine drop a cylinder it was a defective valve seat in my civic. I hope it's nothing to serious.

06-02-13, 12:11 PM	#8
gt900uk Guest Posts: n/a	Re: Rear Cylinder not Firing Whats the best method to get access to the coil pack? Do i need to take the tank and airbox off?

06-02-13, 02:27 PM	#9
Sid Squid No, I don't lend tools. Mega Poster Join Date: Jul 2003 Location: Skunk Works, Nth London Posts: 8,680	Re: Rear Cylinder not Firing Clarification: K8, twin plug, yes? However thus far you've only referred to 'the plug', have you made certain both plugs are connected correctly? If either plug doesn't fire, it's partner won't either. Make sure of the connections first, both LT and both plug caps. If all seems well, take both plugs from each cylinder and fit them to the other, does the problem move from one cylinder to the other? __________________ If an SV650 has a flat tyre in the forest and no-one is there to blow it up, how long will it be 'til someone posts that the reg/rec is duff and the world will end unless a CBR unit is fitted? A little bit of knowledge = a dangerous thing. "a deathless anthem of nuclear-strength romantic angst"

06-02-13, 03:24 PM	#10
gt900uk Guest Posts: n/a	Re: Rear Cylinder not Firing There is definitely only one plug, just noticed my typo above its on an 07 reg. I am going to buy some new plugs on the way home from work tonight and change them over. I shall see what else i can change over between the two cylinders whilst i am at it. I think i have my multimeter kicking about somewhere so shall try and do some other checks.

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