GS1100 petcock question

[Guest]

Hi guys. I started out on this forum well over 6 years ago but haven't been on in the last 8 or 9 months so I lost my account. I still have my 79 GS850 shaft.
Anyway my question is...I am working on a 1980 GS1100 with BS carbs. The BS carbs are new to me and the bike has had the petcock pulled apart and a snowmobile shutoff put in line. Does the petcock need to be intact for this bike to start. I understand these carbs work on vacuum. I have checked and know that the carbs are getting fuel but the plugs are dry unless I put my hand over the end of the carb.
Any help is appreciated. Thanks.

[Katarat]

The original petcock was vacuum operated but as long as you have a shutoff you will have fuel when its on. The vacuum Hookup on the carbs that fed the old should be blocked. Take the drains on the carbs & loosen then up to see if youre getting fuel first. They will probably not run at all or very badly with the airbox off unless its been jetted for pods. Let us know what you find & we will help you. Need more info, how long has bike set since it ran, is gas good etc

[purplemotoman]

Fuel is fresh. Carbs are jetted for pods. There is fuel in the bowls. When I crack the bottom screw it pours gas. Spark plugs are dry. If I put my hand over carb end the bike tries to start but just blows a huge flame out the exhaust. I tore down the carbs, dunked and put back together. I didn't touch the air screw though.

[mrbill5491]

Check your plug wires are on right. If they are, sounds like a timing issue.

[purplemotoman]

First thing I checked was plug wires, firing order and coils. As far as the timing goes, the service manual says that there is no timing to set....or is there?

[Dave8338]

If you're getting a flame out the exhaust, it is firing on an open exhaust valve.
Sure you haven't crossed a plug wire or two ?

[purplemotoman]

I am not 100% sure. I read 1&4 on 1 coil and 2&3 on the other. Firing order is 1,2,4,3 from left side to right.

[yank]

Others will chim in on what maintenance needs to be done. you need to put some kind of an air box, pods or a rag would be better then your hand.

[purplemotoman]

Thanks. I did put the pods back on.
As far as coils and wires go:
Left coil.
#1 cylinder is bottom of coil. #4 cylinder is top of coil.

Right coil
#2 cylinder is top of coil. #3 cylinder is bottom of coil

Hope that makes sense.

[yank]

I,m thinking you might have the coils wrong.left coil #1 top #4 bottom, right coil #3 top #2 bottom look im your manualif you have one,i could look in the am.

[purplemotoman]

I don't have a manual for this bike. I just picked it up a few days ago. If you wouldn't mind looking tomorrow it would be appreciated. Thanks.

[yank]

What manual were you referrin to in your other posts?

[purplemotoman]

It is an online PDF file from a website.

[purplemotoman]

It was only for a GS1000 though.

[yank]

A forum member Basscliff has a great site with your manual, go to the contacts and you will find him.