'80 GS100G questions

[haggis905]

The Background:

I picked up a 1980 GS1000G with 33K on the odometer a couple weeks ago and knew that there were several things I needed to do before trying to turn it over. It has been sitting for at least a couple years according to the pink slip. Here was the 'to do' list:

Rebuild carbs (including the new o'ring kit and gaskets) checked float height and adjusted according to the manual
clean electrical connections
oil change (FULL of gas, FRAK!!) and replace oil filter
charge battery
Replace plugs with new ones gapped to manual specs

The Issue:

I buttoned it all up this morning and kick it over several times (pre-gas) to get the oil pumping through the filter and everywhere else. When I did add gas to the bike, it fired up immediately, but the left pipe is sending smoke signals that can be seen from any satellite. Adjustment screws are 2 1/2 turns out for starts and there is some bogging when the throttle is turned. I ran it for several minutes to see if it would clear up but had to turn it off as I could no longer see anything nearby.

Could the smoke be caused by the gas that was in the engine, or is there something else that may need tending to, such as the valve seals (yes, I looked before I asked ). Any and all ideas are appreciated.

TIA

[Redman]

Would you say the smoke is blue or is the smoke white?

Did it do it for long time (more than 10-15 seconds)?

Did it do it again after sitting for a while (overnight) again?

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[Griffin]

Could be a bad petcock leaking gasoline through the vacuum line and dumping it directly into number 2 carburetor.

Happened to me on my 550L when I first got it going after it sat for almost twenty years. I'd start it and it would smoke like a Hollywood smoke machine out the left pipe. I checked the plugs, #2 was competely sooted over.

Changed out the petcock for a new one, problem was solved.

[haggis905]

Would you say the smoke is blue or is the smoke white?

Did it do it for long time (more than 10-15 seconds)?

Did it do it again after sitting for a while (overnight) again?

.

Redman,

The smoke is definitely white. It did it for the entire time I ran it, say 7 minutes, or two full bowls of gas in the carbs. This occured whether the choke was on or I had it on idle. I only fired it up this morning for the very first time so no information as to the overnight part. It has sat for at least a year plus with about 2 quarts (minimum) of gas in the oil.

[BassCliff]

Hi,

Is the petcock working properly? Is gas leaking down the vacuum line into the carbs? Just a thought.

Blue or white smoke could indicate valve seals or piston rings. If it's just a stuck ring it might loosen up if you just ride the snot out of it.


Thank you for your indulgence,

BassCliff

[haggis905]

I'd start it and it would smoke like a Hollywood smoke machine out the left pipe.

Griffin,

That's exactly my issue, except that I am using a temporary tank to feed the fuel and have the vacuum line plugged, just as if I was going sync the carbs, which I was with a Morgan Carbtune.

[haggis905]

Hi,

Is the petcock working properly? Is gas leaking down the vacuum line into the carbs? Just a thought.

Blue or white smoke could indicate valve seals or rings. If it's just a stuck ring it might loosen up if you just ride the snot out of it.


Thank you for your indulgence,

BassCliff

Thats what I was thinking too, but wanted to get some opinions from the people that I respect when it comes to these bikes, i.e. yourself, Griffin and many, many others. No petcock yet as I was just getting ready to CarbTune the bike.

[haggis905]

Griffin,

I see that you also have a a980 GS1000G. In the manual I downloaded from BassCliff's site, it says that it should have the Mikuni VM26SS carbs, yet I KNOW that the carbs on the bike are Mikuni CV carbs, because I have rebult several of them over the years. Can you verify the VM for me? This could be the cause of my problem. Also, I noticed that the floats were set WAY lower than what the manual suggested, something like 20mm +/- 1. I corrected them for the VM carbs, not the CV carbs that are on the bike.

TIA

[Steve]

Griffin,

I see that you also have a a980 GS1000G. In the manual I downloaded from BassCliff's site, it says that it should have the Mikuni VM26SS carbs, yet I KNOW that the carbs on the bike are Mikuni CV carbs, ...

Not sure about that manual, but the factory manual for the 850 shows the '79 model in the first part of the book, then goes into supplemental chapters, showing the CV carbs and other differences.

Maybe your book does the same thing?

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[Griffin]

Griffin,

I see that you also have a a980 GS1000G. In the manual I downloaded from BassCliff's site, it says that it should have the Mikuni VM26SS carbs, yet I KNOW that the carbs on the bike are Mikuni CV carbs, because I have rebult several of them over the years. Can you verify the VM for me? This could be the cause of my problem. Also, I noticed that the floats were set WAY lower than what the manual suggested, something like 20mm +/- 1. I corrected them for the VM carbs, not the CV carbs that are on the bike.

TIA

That is the 1978 GS1000 manual. There are supplements for the 1979 GS1000E and S, the 1980 GS1000E, the 1980 GS1000G, and the 1981 GS1000G.

I have all the supplements in addition to the base manual. If you need more info on your G, pm me.

[haggis905]

Not sure about that manual, but the factory manual for the 850 shows the '79 model in the first part of the book, then goes into supplemental chapters, showing the CV carbs and other differences.

Maybe your book does the same thing?

.

Thanks Steve, your dead-on; I remember having to check that on my GS1150. Looks like I have the Mikuni BS34SS carbs and the float heights are all off by at least +3 because I didn't RTFM.

[haggis905]

If you need more info on your G, pm me.

Thx, much appreciated. I have the wrong float heights set; I am going to redo them then try again.

[haggis905]

Update

Thanks Steve and Griffin for reminding me to RTM. I reset the float heights to the correct setting and reinstalled the carbs; no smoke whatsoever, just a smooth running 1000G. Used the Morgan Carbtune on the bike and 5 minutes later went for a qiuck ride around the neighborhood. It accelerates smoothly and quickly. I can't wait to get the tank cleaned (slight rust inside, as in a small cirlce here and another there) and reinstalled then take it out for a good long ride.

Thanks again for the assistance!

[Steve]

Thanks for posting the resolution.

It's always nice to know that another bike is back on the road successfully.

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