1980 GS1100 plugs fouling

[Anonymous]

Hi. I had my 80 GS1100 in storage for 20 years and got it on the road last summer (after having the carbs rebuilt out of town). The plugs foul quickly around town and the bike is almost unrideable then. It runs fine on the highway with clean plugs. I took the head off thinking I need new guides or seals and then I learned about this site and that a rich fuel-air mixture causes fouling (my plugs are very sooty - No. 1 and 2 more than 3 and 4).

The bike does not blow smoke when it is running. Should I be concerned about the valve seals?

Thanks for any input.

Patrick

 

[earlfor]

Re: 1980 GS1100 plugs fouling

If it runs fine out on the highway and the plugs stay clean, then it sounds to me like all that is wrong is the adjustment on the pilot
jet and airscrew. I had the same problem on my 750E and it just took some tweaking. I dont have an 1100, so cant tell you what the setting should be, but there are more 1100 owners on this site than anything else.

Earl

Hi. I had my 80 GS1100 in storage for 20 years and got it on the road last summer (after having the carbs rebuilt out of town). The plugs foul quickly around town and the bike is almost unrideable then. It runs fine on the highway with clean plugs. I took the head off thinking I need new guides or seals and then I learned about this site and that a rich fuel-air mixture causes fouling (my plugs are very sooty - No. 1 and 2 more than 3 and 4).

The bike does not blow smoke when it is running. Should I be concerned about the valve seals?

Thanks for any input.

Patrick

 

[Anonymous]

Valve guide seals

Valve guide seals

My bike apparently sat as well, and the valve guide seals are leaking.
You'll probably only get the black smoke at start-up. Running it probably won't be noticeable.
My plugs are a bit sooty too.
If you want to see if it's your seals, just pop the pipes off, and look into the exhaust ports. You would probably see black oil tricklng down the valve stems.
Not imperative to fix right away, I'll wait till fall and replace them myself.
Expensive little rubbers tho. They want $6 CDN each valve guide seal.
16 of em, I fell raped on this 10 cent part...

 

[Jay B]

What Octane fuel are you running

What Octane fuel are you running

3 things to try. 1 If you are running 91 or 93 octane try coming down to 87 or 89. Sometimes running too high in the city will cause this. 2. Also check your air flow. If your not getting enough airflow at the lower speeds it will cause it to run rich in the city and then when you hit the highway it levels out. 3. Check your plug gap. If your running mostly city gap the plugs to the smaller number and if your running mostly highway gap towards the higher number. Dont know why it works that way but on most (not all but most) of my bikes no matter what make it works. One other thing...What ever you try only do ONE thing at a time to try to fix it. That way you'll know what worked and what didnt for future reference.

 

[Anonymous]

1980 GS1100 Plugs Fouling

1980 GS1100 Plugs Fouling

I sincerely appreciate the valuable advice and suggestions. Thank you.

I will read up on carb adjustments (previous forum discussions) although it seems a bit like a black art right now!
The exhaust ports are covered in a uniform layer of soot (no oil staining visible) so the seals may be okay (?). I will check for smoke when I get it running. Six dollars per seal is robbery (a whole gasket set costs a hundred dollars - aftermarket).
I have run regular unleaded fuel in it since I got it on the road last autumn and will try the gap adjustment suggestion once it is running again.

Again, the advice is appreciated. Thank you.

Patrick