Timing setting for 85 GS550L ??

[hikermikem]

I haven't a manual, does anyone know the proper timing set up for this "L" model engine??

I've been slowly fixing numerous problems with this bike & am running out of things to check. Many of you have given me very good advice regarding lots & lots of questions I've had while troubleshooting this bike. Needless to say, all the standard stuff has been either checked or replaced:

Carbs (dipped)
valve adj
intake O-rings & boots
petcock & fuel line
vac leaks
fuel level in bowls (using tube method)
Comp check (140, 140, 150, 155)

Idles well at 1500, but has ZERO power - backfires & stumbles when getting on the throttle. I'm still playing with the adjustment screws, but they're all set somewhere between 1.7 - 2.5 turns out, depending on how high I could get the idle up.

I will be doing a carb vac sync when I get the gage from a friend (next week), but I wanted to check the timing, as it seems to run like it's out of time.

I am considering raising the jet needles as a last resort, unless the timing check & vac sync make a major difference for the better.

Any other suggestions??

Thanks Mike

[Nessism]

Sounds like you have done a good job regarding the usual suspects so to speak. Just wondering if you have changed the air filter and/or exhaust? If so, you will have to rejet. If not, I'm stumped other than to say that carb sync is not likely the issue unless it is WAY off. I don't know how to check timing on a 16v engine (yours is 16v isn't it?) Only other thing to suggest is maybe check the spark plug caps? Good luck.

[hikermikem]

Thanks for the response:

new air filter (paper, not oiled)
stock airbox & exhausts

Do you know anything about signal generators?? I was wondering if the electronic timing advace is working? Any way to check it??

[LeeGS550E]

You can't change the timing on the 16v 550. This is done electronically by the signal generator. There is a factory manual at repairmanualclub.com that will give you the resistance specs and instructions for testing the ignitor. You'll need an ohmeter to do it. I had a very similar problem with my '83 in that the spark was very irratic. A timing light showed the spark signal jumping all over the place. Test your generator with the manual, and I'm guessing you'll find the ignitor unit is bad.

[chef1366]

Does this bike have an electronic advance?

[LeeGS550E]

Yes, electronic advance, not mechanical.