Can't get one cylinder to fire.

[Maulerman]

I have one cylinder of my 1982 GS1100 that just won't fire. Compression is 150 psi warm. I pulled the plug and it is sparking. New coils, wires, plugs. The plug is wet so it seems to be getting fuel but I sprayed engine starting fluid in the carb and the cylinder still didn't fire.

I haven't pulled the cam cover yet. I thought maybe a worn cam lobe?

What am I missing? Any thoughts or suggestions?

[kdo58]

http://members.dslextreme.com/users/bikecliff/

[Big T]

Maulerman, its much more helpful when you're more specific about which cylinder you're having a problem with

I guessing #2?

It's unlikely that a cam lobe is worn, more likely that your valves need adjusting

[dr_fosg8]

Yep, some more information is required.

Is your 82 1100 an E model or G,GL?

How long have you owned the bike and what is the maintenance history?

If it is like Big T said and it is cylinder #2 then maybe you have a bad fuel tap letting fuel in the vacuum line and it is too rich to fire.

[Maulerman]

Sitting on the bike and looking down at the engine, it is the far right cylinder. I can never remember if it is 1 or 4. I am not sure what model it is. Does it matter? It is a 4 valve engine. I don't know what the maintenance history is since I just bought it recently and was told it ran well.

[Big T]

I don't know what the maintenance history is since I just bought it recently and was told it ran well.

That statement is the antithesis of this entire site

You need to do all the maintenance first, like adjusting the valves and cleaning the carbs (which is likely your problem)

You need to go here

http://www.thegsresources.com/_forum/showthread.php?t=196338

and work your way from there

You're hitting all 10

http://www.thegsresources.com/_forum/showthread.php?t=171846&highlight=top+newbie+mistakes

[Larry D]

Adjust the valves and do a carb sync. My GK wouldn't fire on one cylinder before the carbs were synced properly.

[tatu]

If you've got compression its unlikely to be a vlv issue, and if the plug is wet you have fuel, that leaves the spark, try swapping the cap and plug with another cylinder and see if the problem persists or moves. NGK plugs don't handle getting wet with fuel well and a spark mightn't be the same under compression

[btbarb]

Order

Sitting on the bike and looking down at the engine, it is the far right cylinder. I can never remember if it is 1 or 4....snip...

Sitting on the bike, cylinder order is from left to right, that's #4.

[Maulerman]

Thanks for your advice. I cleaned the carbs once but maybe not as thoroughly as needed. I considered the compression suppressing the spark but I wasn't sure.

I appreciate the input. I guess I have some work ahead of me.

[argonsagas]

Easiest spark test is to swap leads between cylinders 1 and 4.

The coil fires both plugs at the same time, so a strong spark at #1 would be just as strong on # 4

If that works, and # 4 fires up, then you need new plug wires.

[argonsagas]

Easiest spark test is to swap leads between cylinders 1 and 4.

The coil fires both plugs at the same time, so a strong spark at #1 would be just as strong on # 4

If that works, and # 4 fires up, then you need new plug wires.

Having a clean plug in both of them before doing this is essential.