GS550E dies when warms up

[mat163]

I have a 1985 GS550E that has kept me very busy fixing numerous problems. I finally had it running right, and was starting to get very optimistic. I was on the way to my midterm the other day, when it decided to die on me at 40MPH. It just died with no warning. All of the dash lights were on, the starter worked, and fuel was flowing (I pulled the fuel line to see if it had fuel), but It wouldn't start back up. I got a ride and left the bike on the side of the road. When I returned 3hrs later, it started right up. I rode it home (10 Miles), and it seemed to run fine. I decided to keep riding, and 2 miles later it died again. It acted almost like it ran out of gas.

After taking it home, I deduced that when the bike was fully warmed up, all spark plugs lost spark at the same time. Doing the usual tests and replacing the battery, I narrowed the problem down to the Signal Generator. I am missing continuity from GR to Blk/Wht (the left receptor on the generator). The Brwn to Blk/Wht is fine (the right one).

I decided to post this for two reasons:
1. To help out anyone with a similar problem
2. I was wondering if someone knew where i could get a replacement signal generator for cheap (the dealer wants $200) or a way to repair the current one.

Thanks.

[BassCliff]

Greetings and Salutations!

Hi Mr. mat163,

Thank you very much for sharing your experience. Yes, those units are a little pricey. You can check ebay or this forum's 'Parts for Sale' section. Look for a bike similar to yours that is being parted out. Be sure to compare part numbers if you are considering a part from a different model. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.


Thank you for your indulgence,

BassCliff

[magelord]

I had to replace mine, got lucky and bought one off a guy at a scrap yard for 60$. make sure you buy from a place that lets you return because you wont know if it works until you plug her in.

[salty_monk]

Get yourself a Dyna S from Z1 enterprises. Will sort it out for good $120.

If you have a late model bike with electronic advance you'll need the mechanical advance from an earlier model. Should cost about $5 on Ebay or somewhere....

Dan

[p_s]

I have a spare signal generator if you're sure that's what you need.

[smoothbomber23]

My bike was doing the same thing but i dont know if that was the problem? I was able to start my bike back up but had to keep the idle around 2000 RPM's in order to keep her running. I was wondering if that was also the same problem or completely unrelated????

[chef1366]

Sounds like an Igniter. Troubleshoot both the generator and the igniter and get a Dyna S.

[salty_monk]

Yep the signal generator behind the right hand cover doesn't tend to go wrong, I think I have one somewhere but you'd have to add your wiring to it as I cut it off mine... more likely to be the igniter in my opinion as Chef says.

Dan

[mat163]

I think it's weird that only one side of the signal generator is bad, and it is only bad when the bike warms up. I know the wiring is not compromised between the generator and the plug, so the problem just lies within that piece. Thanks for all your help.

[salty_monk]

My igniter showed a fault on plug 3 only & only after 5500rpm... It's electrical, 30 year old electrics do a lot of funny things....

[mat163]

Just an update, I got another signal generator and installed it. The bike runs good and no longer dies when it warms up. It seems like it has less power, but I think it's just me.