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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Dbuckley13 on August 05, 2019, 06:02:19 PM

Title: Spark out of cylinder, but not in
Post by: Dbuckley13 on August 05, 2019, 06:02:19 PM: 93 K75 sat for almost 2 years pulled, new battery with fresh gas and ran like new out to my shop. Did full clutch spline lube with all general maintenance on the way out. Bike ran fine the out of no where starts running only on the 1 and 3 cylinder. Pulled 2 plug grounded to cylinder and have huge blue spark looks great. Put it back in on he head and back to no spark. Swap 1 and 2 coils around and now only 3 cylinder will fire. Bought new plugs and will be installing them in a few days to see what that does. Any help would be awesome, thanks!
Title: Re: Spark out of cylinder, but not in
Post by: johnny on August 05, 2019, 07:07:40 PM: greetings...

we need to see some photos of this moto... need to see how factory is it...

j o
Title: Re: Spark out of cylinder, but not in
Post by: Laitch on August 05, 2019, 07:56:12 PM: Quote from: Dbuckley13 on August 05, 2019, 06:02:19 PM
Any help would be awesome, thanks!
The high tension lead for #2 might be damaged and twisting it for testing could be restoring contact. Your description of what happened when you swapped coils is eluding me. You move coil 2 to coil 1's position attached it to 1's primary, and moved 1 to 2's position and attached it to 2's primary? You need to change the primary wires too. You now have only one cylinder firing instead of two or three cylinders firing?
Title: Re: Spark out of cylinder, but not in
Post by: Dbuckley13 on August 05, 2019, 07:57:02 PM: Very very factory, only mods are progressive rear spring. Also on its second rear drive as the original Shock mount broke off leaving me to look like a low rider on the side of the road
Title: Re: Spark out of cylinder, but not in
Post by: Dbuckley13 on August 05, 2019, 07:59:43 PM: Quote from: Laitch on August 05, 2019, 07:56:12 PM
The high tension lead for #2 might be damaged and twisting it for testing could be restoring contact. Your description of what happened when you swapped coils is eluding me. You move coil 2 to coil 1's position attached it to 1's primary, and moved 1 to 2's position and attached it to 2's primary? You need to change the primary wires too. You now have only one cylinder firing instead of two or three cylinders firing?

Yes I switched primaries as well and now it’s running on one cylinder, #3 the only one that hasn’t been molested at all
Title: Re: Spark out of cylinder, but not in
Post by: Laitch on August 05, 2019, 08:17:49 PM: What color is the primary wire on #1?
Title: Re: Spark out of cylinder, but not in
Post by: Dbuckley13 on August 05, 2019, 09:18:39 PM: Quote from: Laitch on August 05, 2019, 08:17:49 PM
What color is the primary wire on #1?

Green/yellow and there’s a blue in that plastic plug
Title: Re: Spark out of cylinder, but not in
Post by: The Mighty Gryphon on August 05, 2019, 09:26:45 PM: Does the plug in question have any carbon on the electrode?

Once in a while you will run into a spark plug that will not spark under compression, but sparks fine out of the engine. Put everything back to where it was and put the new plugs in, then get back to us.
Title: Re: Spark out of cylinder, but not in
Post by: Dbuckley13 on August 07, 2019, 02:44:02 PM: Well sure as hell, new set of plugs and it runs great, others had just enough carbon on them to cause the issues I guess. Local store only had D7EAs but seems to run great.