FZR Backfiring and misfiring has me baffled! HELP!!
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turbovwfzr
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- Joined: Sun Aug 28, 2016 11:10 am
FZR Backfiring and misfiring has me baffled! HELP!!
Ok so I have a 1995 FZR600 with about 20k on it. It had a valve adjustment at around 15k the previous owner said but I don't know about that and I don't think that the valves have anything to do with this because anything valve related usually is progressive and it has ran great up until about a month ago. Out of no where on my way home from work it started backfiring and sounding like it was misfiring at low RPM. But high RPM it rips. When you rev it up to about 3500rpm it sounds like it misfires, most likely only 1 cylinder is misfiring, and it kind of sounds like a Subaru boxer engine to be honest. So I've already changed the plugs and cleaned the carbs as best I could without taking them apart and it still does it. I still have to test the plug wires, but has anyone else had anything like this happen? Anyone have any ideas on what the issue could be? Thanks in advance!
Re: FZR Backfiring and misfiring has me baffled! HELP!!
If you are getting backfiring I would say one of your carbies is flooding. Try syncing the carbies, should show you which is causing the problem.
Re: FZR Backfiring and misfiring has me baffled! HELP!!
I think a bad battery or charging system will show up as the symptoms you mention. Click on "WIKI" as the top of this page and look for "VR Trouble Shooting".
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lhartman89
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- Joined: Sat Jul 02, 2016 11:24 pm
Re: FZR Backfiring and misfiring has me baffled! HELP!!
I recently went through a whole ordeal where my bike started missing and running rough. My problem mostly happened after riding for 10-20 miles after the bike warmed up.
I would check the spark plug caps by giving them a little tug. If they pull right off the wire maybe trim back some of the leads and screw the caps back into the leads. Make sure you are getting 13.7-14.5 V while running. My issue was the wiring from the stator to the vrr was shorting causing heat which caused me problems.
There is a 3 prong white connector on the left side of the bike under the gas tank that connects the stator to the vrr. The wires from the vrr to the battery were also in bad shape so I hardwired everything. I took 12ga wire and soldered from the stator leads back to the vrr. Then I ran 12ga wires from the vrr to the battery with a 30 amp fuse close to the battery between the positive on the battery and the vrr and my problems were fixed. I am at a stead 14.4V now no matter what rpm range. Basically the ignition system on these bikes are power hungry and if they are not getting the voltage they need, the bike will start breaking up and running rough.
If you haven't already gone through the carbs, it would be a good idea. I knew my problem was with the electrical system as I had completely gone through everything else on the bike. Does the bike hold a steady rpm at idle? When I first got my bike running, I would either that 3k rpm or it would want to stall. I had to take the carbs apart and clean the jets. It would also be a good idea as mentioned to sync the carbs.
I would check the spark plug caps by giving them a little tug. If they pull right off the wire maybe trim back some of the leads and screw the caps back into the leads. Make sure you are getting 13.7-14.5 V while running. My issue was the wiring from the stator to the vrr was shorting causing heat which caused me problems.
There is a 3 prong white connector on the left side of the bike under the gas tank that connects the stator to the vrr. The wires from the vrr to the battery were also in bad shape so I hardwired everything. I took 12ga wire and soldered from the stator leads back to the vrr. Then I ran 12ga wires from the vrr to the battery with a 30 amp fuse close to the battery between the positive on the battery and the vrr and my problems were fixed. I am at a stead 14.4V now no matter what rpm range. Basically the ignition system on these bikes are power hungry and if they are not getting the voltage they need, the bike will start breaking up and running rough.
If you haven't already gone through the carbs, it would be a good idea. I knew my problem was with the electrical system as I had completely gone through everything else on the bike. Does the bike hold a steady rpm at idle? When I first got my bike running, I would either that 3k rpm or it would want to stall. I had to take the carbs apart and clean the jets. It would also be a good idea as mentioned to sync the carbs.