Issues with cyl #2 not running

[Guest]

My bike is a 80 GS1000E with pod filters, stock pipes, DJ stage 3 jet kit currently running 165 mains. A/F screws are out 2.5 turns. I have been having persistent issues with the #2 cyl not running right since I bought my bike. So far I have:

Clean/rebuilt carbs with new 0-rings
Installed DJ stage 3 kit
Replaced intake boot 0-rings and 1 boot (I tore it)
Replaced Petcock with a Pingel unit
Capped vac port on #2 carb with a nipple cap
Bench synced carbs
Vac synced carbs with DIY manometer (PVC hose, marvel mystery oil)
Checked Valve clearances
Swapped cyl #2 and cyl #3 plug wires to rule out ign issue
Checked combustion color using a Colortune
Checked A/F screew for a broken tip


The issue Im having is this: Upon start up/warm up, cyl #2 doesnt get hot thus, must not be running. I can putt around town alright but as soon as I give it 2/3 throttle or more, from then on, the bike runs like complete crap. I just got done checking my valve clearences today so I put her all back together again and went for a quick ride. Riding through my development at low speeds, the bike felt 'alright'. I got on to the main road and just got up to speed slowly and cruised at 35-40 without any issues. I turned onto a back road and opened her up a little once I saw there wasnt anyone else on the road but me. Got throught 1st, 2nd, 3rd, and into 4th, at about 2/3 throttle. Got of the gas in 4th crusied for 1/2 mile before getting back on the gas. When I gave it some throttle, the bike bogged down, lost most power and acted as though it was trying to get fuel. I clicked it into 5th and limped it the 1.5 miles home, almost every time I got off the gas on my way home, the bike would backfire or pop. While cruising home, The bike would surge and fall, surge and fall. Pulled into the garage and checked the plugs. 1,3 &5 are all nice and brown . #2 on the other hand, looks brand new (it was, prior to this ride) with the exception of the center electrode and the insulator tip being coated by a thin film of fuel.

I keep replacing things, hoping that each thing I replace will fix the problem but the problem hasnt gone away and hasnt changed. Cyl 1,3 & 4 are all good but I cant get the #2 cyl to run properly. Using the Colortune, I can see that it is getting spark, but it isnt igniting. I know its getting fuel as well because the plug fouls out and smells like fuel when I remove it. Im at a loss, Im frustrated, and I just want to ride. Ive always been a DIYer but Im at a point where I just want to take the bike down to a shop and have them fix it so I can enjoy the riding weather we are starting to get here in NC. Im asking you, all of you, PLEASE HELP! Any suggestions will be tested.

[chef1366]

Check and make sure the fuel line isn't kinked when you put the tank down

[DrImodium]

Check and make sure the fuel line isn't kinked when you put the tank down

Line is new and is put on the tank after it's in place. No kinks, or bends. flows directly to the fuel nipple.

[Big T]

Have you tried swapping plug leads 2-3 to see if the problem stays at #2 (thus eliminating coil/ignition issues as cause) ?

[Steve]

The clean plug seems to indicate a non-firing problem.

You say you swapped #2 and #3, but apparently the problem did not move.

The part that did not move is the spark plug. Swap #1 and #2 plugs, try it again.

This would not be the first time that a "new" plug was found to be defective.

.

[DrImodium]

I've bought and gone through a case of plugs trying to diagnose this issue. The plugs all get healthy spark. Keep in mind, I used a colortune which allows you to see into the combustion chamber where I could see a strong spark but no combustion.

[Steve]

I know you said you checked valve clearances.

If there might have been a bit of crud on the seat of one of the valves in #2, it might be gone now, and the valve is not opening correctly.

On the other hand, if you have some crud that has lodged there since your valve check, the valve is not closing correctly. No compression, it won't fire.

If that is not the problem, then it has to be fuel, because you only need three things for the engine to work:
a proper air/fuel mixture, sufficient compression and a properly-timed spark.

You have seen a spark. The fact that it runs on the other three cylinders kind of implies that it might be properly-timed.
The air-fuel ratio might be off.
Compression might be off due to valve clearance.

Don't expect a shop to help you on this, most of them have a 10-year rule. If you bike is more than 10 years old, they won't work on it.

.

[rustybronco]

#2 on the other hand, looks brand new (it was, prior to this ride) with the exception of the center electrode and the insulator tip being coated by a thin film of fuel.

I know its getting fuel as well because the plug fouls out and smells like fuel when I remove it. Im at a loss, Im frustrated...

That should be a hint right there.

also, what are your compression readings? no sense trying to get it run right if the compression isn't up to snuff.

[DrImodium]

Havent done a compression test yet. Ill try to get my hands on a compression tester.

[nufnuf]

Blocked pilot jet No 2???
Dont give up
When you finally fix it the sense of satisfaction will almost make up for the speeding ticket.

[DrImodium]

Went to autozone and rented one of their compression testers. I didnt warm the bike up and it hasnt been ridden for 2 days. These are the results:

1-50
2-50
3-45
4-50

I can understand #3 being off a little because I know I need to swap one of the shims. The numbers are all REALLY low but Im thinking it could be the gauge that I used:



When it run right, It feels great. I have a hard time believing the rings are fried or the valves are burnt because I dont get smoke from the exhaust, it starts up first time every time, and generally runs alright until #2 starts acting up. All of the other plugs are nice and brown too.

One thing Im also thinking is the tank isnt lined so there is some crap in the bottom of the tank. I cleaned the tank out a few weeks ago with some Evaporust and then rinsed the tank out with a garden hose but didnt line it so. If there is still crud in the tank, I would assume it would gather in the #2 carb since that is where the fuel line connection is so it must pass through the #2 carb first.

What do yall think?

[tkent02]

When you did the test, throttle wide open? All the plugs removed and fully charged battery to get a really high cranking speed? If not, the test is no good, if you did, try it again with the engine hot, then if it's still low do a wet test.

Maybe all of your valves are way too tight?

It just seems odd for all of the numbers to be so low, yet be so even.

[tkent02]

Throttle was WO but plugs were not removed. Ill go do that right now and post back the results.

Ride it around the block first to get it warmed up a little?

[DrImodium]

Throttle was WO and I just did it again will all plugs removed with the same results. I checked the valves on Tues and got these results:

1 In .63 Ex .76
2 In .38 Ex .63
3 In .32 Ex .102
4 In .38 Ex .63

I know I need to adjust Cyl #3 but all the others are in spec.

[rustybronco]

1-50
2-50
3-45
4-50

Those are the highest readings as in they won't go any higher??? me thinks you did something wrong.

***edit*** is the schrader valve in the end of the hose? does the release button on the gauge leak?