I took GRiSO out the other day. Was 3rd ride since purchase. Ran great first two times out. This time was like it never warmed up. I stopped and touched exhaust pipes and the right side was cool and the left side was hot. So I got home and pulled plugs. Right side seemed dry and was a little darker than the left. I took off plug wires and coils and ohmed them out. Right wire was a couple hundred ohms higher.
Was thinking about swapping coils and wires and seeing if things are the same. Maybe then swapping injectors.
Good idea? I know there are actual mechanics here, would appreciate any advise
Patlikestolean GRiSO Capo
Posts : 70 Join date : 2017-12-07 Age : 55
Subject: Re: dead cylinder Sat Dec 11, 2021 11:53 am
Have you replaced your spark plug boots with the NGKs yet? Originals are notorious for tearing if not removed properly.
Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: dead cylinder Sat Dec 11, 2021 12:52 pm
That would be my first guess. How did you remove the caps?
kiwi dave GRiSO Capo
Posts : 735 Join date : 2014-04-23 Age : 77
Subject: Re: dead cylinder Sat Dec 11, 2021 12:54 pm
I followed a Moto International recommendation and fitted NGK CR8EIX Platinum plugs with NGK SB05F spark plug caps. Had no issues since.
jg213 Montanarolo
Posts : 22 Join date : 2021-09-27 Age : 66
Subject: Re: dead cylinder Sat Dec 11, 2021 3:21 pm
I removed plug caps using tie rap slipped underneath and they popped right off. These are moto guzzi parts, and look like new. When checking resistance I manipulated them to see if I could get intermittant resistance reading. They seem solid.
Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: dead cylinder Sat Dec 11, 2021 3:57 pm
What tends to happen is they tear at the right angle at the top of the cap and the spark then arcs to earth at the plug tube or rocker cover. If you leave the plug cap cover off and fire the bike up you will probably be able to see and hear the spark snapping to earth. Wait until it's dark and it makes it easier.
For future reference never pull the plug caps off from the top. Use a long, thin screwdriver through the cooling tunnel just above the exhaust manifold and flip them off from underneath.
NGK plug caps can be either SB05E or F depending on whether you are using plugs with the 'Hourglass' shaped centre electrode or the threaded type. The final letter suffix demotes the type.
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SMTCapeCod Tiradritto
Posts : 324 Join date : 2020-12-17
Subject: Re: dead cylinder Sat Dec 11, 2021 4:23 pm
I'm sorting out whether to go with straight or angled boot at the plug, having read up on the NGK boot retrofit. I happened upon this picture-thread and it seems like a sound approach- still requires fiddling with a terminal at the coil end. Click to scroll left, to go through the comments sequentially: [You must be registered and logged in to see this link.]
jg213 Montanarolo
Posts : 22 Join date : 2021-09-27 Age : 66
Subject: Re: dead cylinder Sat Dec 11, 2021 4:42 pm
Well I swapped coils and plug wires left and right and the right side still isn't heating up. So, something going on with injector? Is it ok to swap injectors? Or maybe listen for operational sounds or something?
oh, plugs are NGK CR8EKB
Last edited by jg213 on Sat Dec 11, 2021 4:54 pm; edited 1 time in total
lcjohnny GRiSO Capo
Posts : 1470 Join date : 2016-01-25 Age : 69
Subject: Re: dead cylinder Sat Dec 11, 2021 4:52 pm
Is the plug to your injector correctly fitted? - It is one of those where you have to press the surrounding wire clip like on car injectors.
I beleive that any fault further up than connectors should show up as an error on the dash board
As regards plug leads I found that that when they are pressed into contact with the plug the NGK SB05 cap ends just below the end of the plug tunnel so the cable has an easy turn under the plastic cover.
Personally i would avoid silicone leads - had too many problems with them giving faults with no clues but YMMV.
beetle GRiSO Capo
Posts : 10200 Join date : 2013-09-30
Subject: Re: dead cylinder Sat Dec 11, 2021 5:48 pm
Pull the plug and test it with GuzziDiag. Rest the end against the valve cover and run the spark test in GuzziDiag. Spark plugs do die.
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Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: dead cylinder Sat Dec 11, 2021 6:07 pm
What year is this bike? If pre 2013 has it been rollerised?
Yes you can swap injectors. Do you have the Guzzidiag suite of tools?
Trogladyte Grignapoco
Posts : 137 Join date : 2016-03-11 Age : 65
Subject: Re: dead cylinder Mon Dec 13, 2021 6:23 am
So, what's the news? I'm intrigued now.
Is it fuel? Or spark? ( There are other options, but I'm hoping for the best here!)
jg213 Montanarolo
Posts : 22 Join date : 2021-09-27 Age : 66
Subject: Re: dead cylinder Mon Dec 13, 2021 9:30 am
No, don't have any Guzzidiag tools. Will look into that. Bike is a 2016. Has Agostini with baffle and supposedly Beetle map. Maybe I should swap plugs too. Say, if I have dirty injector, what are the options then?
PJPR01 GRiSO Capo
Posts : 213 Join date : 2018-04-24
Subject: Re: dead cylinder Mon Dec 13, 2021 9:56 am
In the event you need a new injector, there are after market injectors on Ebay, work perfectly fine. I swapped out a pair on my Norge...no issues at all. Just find the right compatible ones. I'd replace both, but that's just my preference.
jg213 Montanarolo
Posts : 22 Join date : 2021-09-27 Age : 66
Subject: Re: dead cylinder Mon Dec 13, 2021 12:02 pm
Well I swapped injectors, was really easy, still the left side gets hot and the right side stays cool.
Beforehand I pulled right side plug wire, inserted a screwdriver into cap and laid it close to cover screw. Arced to ground pretty good. Afterwords took a look at the plug end and this time it was wet with fuel. So I guess it had been getting at least some fuel and is igniting mixture
But exhaust pipe stays cool and engine runs rough and doesn't rev up very well at all
Oh, and the right side injector has about .4 ohms more resistance across electrical pins
Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: dead cylinder Mon Dec 13, 2021 12:47 pm
Have you checked the plug cap as suggested?
Trogladyte Grignapoco
Posts : 137 Join date : 2016-03-11 Age : 65
Subject: Re: dead cylinder Mon Dec 13, 2021 1:47 pm
Couldn't this just be a dead spark plug?
lcjohnny GRiSO Capo
Posts : 1470 Join date : 2016-01-25 Age : 69
Subject: Re: dead cylinder Mon Dec 13, 2021 2:13 pm
Plug cap has to be the next (cheap ) replacement - NGK long cap linky (choose thread or that screw plug adaptor as yoiu need) and on mine the HT cable ends were worn away with few remaining strands at each end so some new copper lead was an upgrade
Last edited by lcjohnny on Mon Dec 13, 2021 4:17 pm; edited 1 time in total
beetle GRiSO Capo
Posts : 10200 Join date : 2013-09-30
Subject: Re: dead cylinder Mon Dec 13, 2021 2:16 pm
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Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: dead cylinder Mon Dec 13, 2021 4:10 pm
Plugs are cheap and easy, it's worth a try. If the fuel is stale a fouled plug is far more likely.
The fact you can get a spark to arc from a screwdriver jammed into the cap to the head means not a lot. The spark will always take the path of least resistance and in the open air it will be far more eager to jump a significant gap than it will within the hostile environment of the combustion chamber.
I still suspect a damaged cap.
jg213 Montanarolo
Posts : 22 Join date : 2021-09-27 Age : 66
Subject: Re: dead cylinder Mon Dec 13, 2021 5:57 pm
thing is I swapped plugs, plug wires, coils, and injectors. Made no difference. All that stuff is on the other side now. No doubt will be good preventive maintenance to change out known parts issues, but can't see how it will solve this current problem. I'm wondering doesn't the ECU output identical injector drive pulses? I guess they're timed with crank position?
beetle GRiSO Capo
Posts : 10200 Join date : 2013-09-30
Subject: Re: dead cylinder Mon Dec 13, 2021 6:48 pm
jg213 wrote:
I'm wondering doesn't the ECU output identical injector drive pulses? I guess they're timed with crank position?
No. Each side is independently controlled. This is where GuzziDiag comes in handy. You can test the injectors and spark without running the engine.
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Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: dead cylinder Mon Dec 13, 2021 6:50 pm
There are minor correction factors for the delta cylinder but injection timing is controlled by the phonic wheel at the front of the dummy shaft, (On the 1200-8V). It has a missing tooth and the firing point for each cylinder is determined by that.
If the phase sensor was kaput you would have no fuel or spark.
Steak Godfather
Posts : 3154 Join date : 2013-05-28 Age : 59
Subject: Re: dead cylinder Mon Dec 13, 2021 8:16 pm
jg213 wrote:
No, don't have any Guzzidiag tools. Will look into that. Bike is a 2016. Has Agostini with baffle and supposedly Beetle map. Maybe I should swap plugs too. Say, if I have dirty injector, what are the options then?
Just as an FYI, AF1 in Austin, TX offers an injector cleaning service. I've no experience using this service, but it's an option if needed.
AF1 Racing Fuel Injector Cleaning Service
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2012 MOTO GUZZI GRiSO 1200SE
2013 MOTO GUZZI STELVIO 1200NTX - Orange Blossom Special
lcjohnny GRiSO Capo
Posts : 1470 Join date : 2016-01-25 Age : 69
Subject: Re: dead cylinder Tue Dec 14, 2021 12:06 am
jg213 wrote:
thing is I swapped plugs, plug wires, coils, and injectors. Made no difference.
Hate to go on and on - but in your list of swaps, you did not mention plug caps?
Subject: dead cylinder 
Sat Dec 11, 2021 9:30 am
