Hard Starting GS

[sdbuchert]

My '79 GS1000 has been running great this summer except recently I've had some trouble getting it started. It also doesn't always run smoothly between 1000 and 2500 rpm. When starting, it turns over for about two to three seconds before firing, however it starts immediately (absolutely no hesitation) when push starting. Since it starts easy with a push start, I've ruled out fuel as the culprit, plus the carbs and petcock are freshly rebuilt. I'm assuming the cause to be a weak spark (oh, and the plugs are clean) and will be doing the coil relay mod this week hoping that will solve it. I'm just wondering if anyone has any other suggestions or other things to consider. Thanks in advance.

[doctorgonzo]

Coil relay mod and make sure you're not too lean on the pilot circuit.

[BassCliff]

Hi Mr. sdbuchert,

When was the last time you checked the valve clearances?


Thank you for your indulgence,

BassCliff

[C.V.]

I concur on the coil mod, it fixed my problems.

[sdbuchert]

BassCliff,
Valves were adjust 1000 miles ago. Thanks.

[flyingace]

Check the basics before you do any mods on the coils. It sounds to me like a battery going bad. Does it hold a charge?

[BassCliff]

BassCliff,
Valves were adjust 1000 miles ago. Thanks.

Very good! I also need to check my valves at my next oil change.

If it is electrical (as in voltage drop through the harness), whether or not you do the coil relay mod, have you had a chance to clean all of the electrical connections? Deoxit is a connection cleaner that gets good reviews here. It made a big difference in my bike after I took a little wire brush and cleaned all the connections on the battery, engine grounds, chassis grounds, starter relay, bullet connectors, fuse box, etc.

Unless you've worked on it recently, don't rule out the starter itself. Brushes, starter clutch, etc. Keep us informed.

Thank you for your indulgence,

BassCliff

[sdbuchert]

Flyinggrace,

Battery is new(replaced last August and stored in doors with a full charge over the winter) and holds a charge. The hard starting doesn't happen all the time, just most of the time...especially on a hot day. To me what makes sense is increased resistance due to 30 year old switches and wiring and heat? Thanks.

Spencer

[flyingace]

Because it push starts so easily, you've ruled out a lot of things related to ignition and fuel. If its coils, plugs, wires etc., why would it push start easier than crank start? The only explanation that comes to mind is too low a voltage to the coils when you crank the starter. That's why a weak battery came to mind.

To confirm it's not the battery, next time it's starting hard, hook it up to your car battery (car not running of course) and see if it starts immediately. If it does, you need to evaluate your charging system (see the 'stator papers' on this site).

[sdbuchert]

Flyingace, sorry I got your name wrong in my last reply. I'll try the car battery idea tomorrow when I get a chance. If it is the charging system it isn't too big of a disappointment as I've been considering updating the stator and r/r anyways. BassCliff, thanks for your advice as well. I've been meaning to clean all of the connectors, as the bike has sat in the humid MN climate not running for 12 years...it's just too tempting to ride instead. Now i guess I'll have to take the time to do a little scrubbing. Hopefully she'l be running well for the weekend! Thanks again.

Spencer

[ryonker]

Maybe you've done this, but you can easily check the volts coming to the coils. My coils were only getting barely 9 volts; thus they were being robbed of their potential. Needless to say I did the coil mod. Also, when you did your tune up, did you change points/condensors. I just did mine and it was incredible the difference it made.

Have a great night!

Rick

[sdbuchert]

ryonker,

Thanks for the advice. I haven't checked the voltage at the coils yet, but I'll be doing that before I do the coil relay mod. The bike had a tune up before it was stored and the points and condensors were replaced (or so I was told). I checked the points last winter and they were adjusted properly and in shiny new condition, so I don't think this is the problem. Thanks for your help.

Spencer

[sdbuchert]

Just an update for those that replied. I ended up not bothering with the coil relay. I replaced all original bullet connectors with blade style connectors and cleaned the grounds and multi-prong plugs with DeOxit (also used DeOxit Gold to restore and protect the old connections). I also replaced the original R/R unit with a Duaneage R/R. Problem solved! The bike starts easily and the Duaneage R/R is awsome...the heat sink is much more significant than the stock unit. The new R/R unit handled a 90 degrees day in stop and go traffic without any problems. Thanks to all those who replied to my original post.

[BassCliff]

Cooking with electrons

<sniff> I love a happy ending!


Thanks for the update Mr. sdbuchert.


Thank you for your indulgence,

BassCliff

[tkent02]

The relay mod kicks ass. Full power to the coils. Full size sparks, Instant starts. It's all good.