Fuel mixture too rich, GL1000 - why?

3914 Views 2 Replies 3 Participants Last post by Peterbylt, Sep 29, 2009

thomasthomas

Discussion Starter · Sep 29, 2009

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I have been rebuilding a 1979 GL1000 over the last 6 weeks. Bike runs ok at idle but lacks power.During carb sync with vacuyum gauges Iremove screw in manifold for #3 carb and the engine races from 1000rpm to 3000 rps and stays there. Can't figure out why.

This is what I have done for the last few days.

Friday 9/25:

Randakk kits installed in carbs last week. Cleaned carbs again today and got a little better performance at idle.

The bike starts immediately when cold and idles good. But, even when warmed up, the right carb manifolds are ice cold and the right exhaust is cold and the left manifolds are hot and the left exhaust is hot.

The bike sits there and idles like a champ but lacks power and when driven sometimes won't idle at stoplight- just stops. When restarted it idles OK sometimes.

The pilot jets were at 2 turns and I have increase that to 3 turns with no difference in idle.

And just to aggravate me a little more the starter solenoid died and I have to stick a screwdriver between the solenoid posts to start the bike.

Saturday:

Cleaned the carbs again.

Sprayed carb cleaner all over the outside of the carbs and manifolds looking for leaks- no difference in idle speed.

The right carb manifolds are stillice cold and the right exhaust is cold and the left manifolds are hot and the left exhaust is hot

Synced the carbs with vacuum gauges. Slight change in performance.

Unscrewed sync port on carb #4 and then #2 - slight drop in rpms and some spitting out the hole in #4 but not #2 - sprayed carb cleaner in holes and got momentary increase in rpms and then resumedslightly sloweridle speed from both ports. Put screws back in andregained slight increase in rpms.

Unscrewed sync port screw on carb #3 and engine started racing high from 1000 rpm to 3000 rpm- put finger over hole and rpms went back to normal - sprayed carb cleaner in port and rpms decreased a little but engine was still racing. Put screw back in hole and regular idle rpms resumed.

Unscrewed sync port screw on carb #1 and engine did not race - sprayed carb cleaner in port and didn't seem to get any difference in rpms. Put screw back in port.

Exhaust from left muffler still hot from the start up through warm-up. Exhaust from right exhaust cold until warmed up and then barely luke warm.

Checked valve clearances and AOK.

Checked compression: #1-120psi #2-133psi #3-125psi #4-130psi

Pulled plugs for #1 and #3 cylinders and laid them against frame and both sparked.

I have been talking to helpers on Naked Goldwings and gotten some suggestions but nothing seems to make any difference. One suggestion was to clean vacuum plungers with tin foil but that made no difference.

It's as if the air intake to cylinder #3 is blocked off somehow since it races wildly when I remove the sync screw in the intake manifold.

I have made an obvious error somewhere and I can't find it. Anybody got any ideas?

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Big Cahuna

· #2 · Sep 29, 2009

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a couple of things don't appear correct here. First when you checked compression did you hold the throttle open? My manual says readings below 140 psi indicate a rebuild is needed. Try again, engine hot wide open throttle. Also number three cyl. seems to be the only one working correctly. When you remove the sync plug, your leaning out the fuel mixture thats why it races. On the other ones, it appears from hear that they are not firing especially the ones with the cold intakes. Have you removed the air cleaner and looked in there when its running? It may be flooding over in witch you will see gas pouring from one or more carbs.Or as in the case of my friend, the plenium gasket was dumping gas into the plenium. If that's not the case you should check to see if the floats are set correct. They can fool you especially if your using a clymer manual.

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Peterbylt

· #3 · Sep 29, 2009

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I posted this over on the Naked Wings forum. I think it may apply here.

Until last week I've never been able to get the idle on my 75 quite right.
I've had the carb's apart numerous times and synced them more than a couple of times.

Sometimes she idles at 1000 sometimes at 3000, if put a little drag on the engine it usually drops slowly down to 1000 from 3000.

Last week I went to change out the points and apply Randakk's timing tuning tips only to find that Honda Direct had sent me two sets of right side points so I cleaned the old points, that were in pretty good shape anyway and opened the gap up to .016 from where it was set at .014 at the recommendation of Randakk's tuning tips. I figured I would apply the timing mods when I got the new points.

Suddenly she is idling at 1000 all the time and drops right back down instantly when I let off the throttle. The power and acceleration, which are very good, seem to be unaffected.

I have read in this forum that everything affects everything on these engines. I have come to believe that.

For the moment I am very happy with the performance. Now I am going to change the oil and I hope that does not affect anything else.

Peter

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