07 Bandit 1250 intermittently loosing engine power

[Guest]

Hey Guys,
I need a little help diagnosing an issue I'm having with my Bandit. I'll be cruising along and I'll lose 100% of engine power for a split second. Sometimes it happens once, sometimes it happens repeatedly. Sometimes it gets so bad that I have to pull over and shut the bike off. When it is acting up and I go to pull over, the idle is VERY rough. The RPMs drop to about 900 (from 1200) and struggles to stay running. I can't find any rhyme or reason for it. I have noticed that it happens more frequently when I'm riding 2 up. The bike has Power Commander 3 unit, and everything else is stock. I cant say whether or not it happens on bumps, I haven't noticed it happening when I hit bumps necessarily. Could the heavier load of having a passenger be causing some kind of confusion in the ignition system? I'm stumped.

Last night I briefly poked around in the electrical and couldn't find anything out of the ordinary except for a couple wires that appear to be left over from the old fuel control unit. I plan on taking the tank and plastics off this weekend to really give it a thorough look. I will also clean up whatever electrical

Any ideas and suggestions would be most appreciated.
Thanks,
-Charlie

[Jedz123]

Sounds like your PC3 is compromised... Cut it out or switch to a PCV with auto tune and forget about it...
I've seen those type of issues with PC on the SV and GSX-R forums...
THE PC3 has been superseded for some time. I bet it's your issue.

[SocialAnomaly99]

I thought that too. However, before I decide to spend almost $800, I am going to disable the Acceleration Pump feature and see if that makes any difference.
I still have 79 GS750 project that I really want to get on the road this summer. I'd rather throw the $800 at that.

[Nessism]

Can you disconnect the Power Commander system entirely and see if the problem goes away?

[SocialAnomaly99]

There's another good idea Nessism. I'll give that a try if disabling the acceleration pump feature doesnt work.
Thanks

[bwringer]

Yep, I would also suspect the PC3.

The connectors on these Power Commanders are pure crap. Disconnect it from the fuel injection harness and see if there's any water and/or corrosion in there. Also check the PC3's ground wire.

Guess how I learned about this on my V-Strom...


If the PC3 is not it, then you likely have a bad connector or wire elsewhere on the bike. Suzuki's venerable tradition of undersized, unprotected connectors and shonky wiring continues even to the modern day.

The most common issues are with the ignition switch harness and with the connector leading to the fairing and instruments. Wiggle these around with the bike running and see what you get. Wiggle everything. Disconnect the connectors and look for burns, water and corrosion. The wires inside this harness are also particularly vulnerable.

There's also a doofy little undersized connector atop the main fuse/starter relay widget just in front of the battery under a clear cover. Wiggle and poke this, maybe disconnect it and take a look. Marvel at how stupidly small the pins are that carry ALL the electricity the bike uses.

Also check the kickstand switch and its connector.

If I ever make a pilgrimage to Hamamatsu, I will look up Suzuki's electrical engineers and pimp-slap the lot of them until I can't stand up.

[isleoman]

Before digging into the electronics I suggest you flood the ignition key switch with WD40. What your describing happened on my FZ1 and its happened to other FZ1s. It can't harm things to try and it fixes the same symptoms in most cases with FZ1s. If I'm off base (never owned a bandit) you can try the other suggestions

[1948man]

If I ever make a pilgrimage to Hamamatsu, I will look up Suzuki's electrical engineers and pimp-slap the lot of them until I can't stand up.

Careful, they might know karate.