Starting woes with an '80 SG

[fxrer]

My ’80 SG has developed “cold” starting problems over the last few years which seem to be getting worse. I noted that, along with the other jets, the “starter” jet (or enricher) was reduced from 32.5 for the ’79 H/SH models, to 25 for the 1980 G/SG models.

I have cleaned the carbs several times, the last being about a month ago. I paid special attention to the “enricher” circuit. I removed each starter “needle” (or plunger), and thoroughly cleaned it and the passage ways with carb cleaner, Q-tips and blew out with compressed air. Likewise, I cleaned all other jets (they looked fine to begin with). All jets are standard spec.

The problem seemed to be fixed at first, but has quickly returned. After a week or two sitting, the bike ie VERY difficult to start “cold” irregardless of actual ambient temperature. With the enricher lever pulled out fully, and no throttle, the starter works hard for 30 or more seconds before the motor catches on one cylinder. Then slowly, another will kick in, and finally it will begin to run on all four. Once I drive it ¼ mile, and push in the enricher lever, the bike runs normally at all speeds, including idle. The plugs look fine, with normal color.

Any ideas about how to correct this “cold” start problem, and keep it from returning?

Thanks for any suggestions

[John]

When you cleaned the enrichening circuit, did you also make sure to clean the small passageway in the float bowl itself? The enrichener pick up tube extends down into this, and it is supplied by the fuel that passes through the small orifice in the bowl itself. To check it, fill the passageway that the pick up tube extends into with fuel or cleaner to see if it flows from the passageway into the float bowl itself. There may be some obstruction there.

[Dragonrider]

Are you by chance using the "Prime" position on the petcocks?

After sitting a while, there is little/no gas left in the float bowls...you need vacuum to open the octpous/petcocks and let the fuel flow.

If they are all hooked up right, turning the petcocks to "prime" for a bit will let her start right up.

[fxrer]

John,

Yes, I sprayed carb cleaner down the passageways to the float bowl, as well as all the other passageways and circuits. There was good flow everywhere. The carbs were very clean looking before I started (I ride the bike frequently), but I thought there might be minor varnish or other build up that could be causing the problem. I was encouraged when I put everything back together and the “cold” starts were instantaneous. But after 2 weeks, it was back to being stubborn again.

Maybe dragonrider’s suggestion has merit - to use the “prime” position for startup? Or maybe one or more float levels are incorrect? They have never been adjusted, and I remember checking them a few years ago, and they were correct. But……….. can they gradually get out of adjustment?

Thanks for your suggestions

fxrer