Topic: Issues, Issues, Issues (Update)

[Burke]

Alright, I adjusted the valves and cam chain, and my 77 750 started. Only running on 3 & 4 sometimes 2, and not 1.
Cleaned the carbs, slow jets on 2 & 1 were complete plugged, now clean.

During this time I was soaking my carbs I took my air compressor hose and blew all the crud off my bike.

Once I put the newly cleaned cabrs on , my neutral light would not go on, so it disabled the electric start, zip tie on the clutch and now I am ready to go.

Get it started but it still only running on 2,3,4. But if I put my palm over the intake on 1, I can get it to fire.

1.)Why did the neutral Light go off, did I blow something loose? if so where should I look?

2.) Why doesn't 1 fire unless choked off completly? Would a dirty plug cause this? (I do have spark)

[OldSchool_IsCool]

1) Possibly a wire got knocked off.  Follow the neutral light wire (red w/ green strip, I think) to see if any connectors are loose.  The neutral switch works by grounding the red/green wire, so you could touch the wire to ground to see if the light will come on.  There is a possibility that the bulb burned out coincidentally.

2) When you cover the carb intake, you are choking the air flow.  Chocked air means it will draw just that much harder from the fuel supply, enriching the mixture.  I'd guess your idle mix screw isn't adjusted right.  I'll leave it to others who know your carbs to tell ya how to proceed.

[Burke]

I looked for any thing loose, and wiggled things with the key on to see if it would light, and no luck. If the light burns out would that stop the bike from starting?

[OldSchool_IsCool]

no, a burned out light wouldn't prevent start.  Does the starter motor spin?  Are you having to start it with the kick starter? 

[Burke]

if i hold in the clutch, the starter will work.

[jsaab2748]

make sure the transmission is actually in neutral. A burnt out bulb could be the case at the same time, which will stump you.

[pampadori]

if i hold in the clutch, the starter will work.

i think the later models make you hold the clutch in to operate the starter. 
sync the carbs and mess with the idle mix screws and i bet you'll get cyl 1 firing.  new plug too.

[scondon]

 The neutral switch is located on the underside of the engine and has a light green/red wire connected to it. The switch is basically a spring loaded bearing that will pop into a groove when the transmission is in neutral. If the switch is frozen with gunk it will not seat into the groove and the bike will not know it's in neutral. Also, if the wire is disconnected or faulty you will not be able to use the starter. It is easy to remove and clean/test. A burned bulb will not stop the starter from working.

  The clutch switch will bypass the starter motor safety and allow you to use the starter while in gear as long as the clutch lever is pulled.

   Hard to check proper tune of the carbs with the airbox off as it will change the air pressure in the carb throats and gas won't push up as easy. You should, however, be able to get the pipe hot on #1 so check your idle jet circuit on that one carb. Soaking will loosen things up but those passages are so small you may have to remove the jet to clear it.

[Jerry Rxman Griffin aka MuthaF'er]

New spark plugs?
Whats the resistance across the spark plug caps? A new set will not hurt.
Plug wires good?

These are electrical things that can cause continual or intermittent misfiring on single cylinders. Go beyond these things into the coils or down to the points/electronic ignition and you have problems with sets of cylinders ie 1 & 3 &/or 2 & 4. These are very simple things to check that you should do anyway. Insure you have proper electrical conduction to each cylinder THEN worry about carburation and air flow.

[Burke]

I located the neutral switch on the bottom of the engine, loosend the connection then sprayed it with cleaner, and then it worked. However the light is burnt out.

I also went back and rechecked valve adjustment.

I took my carbs back off and looked in the pilot screw on #1, i sprayed cleaner in there it looks clean.

I did buy new plugs, but the guy at the counter gave me the wrong ones, and I didnt notice till I got home ( I was distracted by the tool isle). So Monday I plan on getting the right plugs.
I did not even try to start it again with out them.

Meanwhile I swapped the tail light with a spare one I had. got that to work, cleand all the blinkers, and the other electrical connections. From what I have seen it looks like this bike sat out side longer than the PO said.

I am also waiting on a choke cable so I dont have to hold the choke lever with my hand. this should be in hand by Tuesday.

[eurban]

I am also waiting on a choke cable so I dont have to hold the choke lever with my hand. this should be in hand by Tuesday.

On your current choke cable, did you adjust the the plastic knurled nut that provides resistance to the choke knob shaft?  It is located underneath a rubber cover and it seems pretty common for people to not know of its existence or how it works.  Pull the choke knob up, remove the rubber cover and tighten the plastic knurled nut until there is enough resistance to keep the choke knob from sliding back down on its own.  . . .Your firing problem could be a number of things but I still suspect that you have a carb issue.  Perhaps you didn't get the #1 carbs pilot circuit properly clear or perhaps the fuel level in its bowl is not correct.  Certainly, check the easy things first (you can use clear tubing to check the level of fuel in your bowls) but you might just have to get back into your carbs again . . .

[jtrain]

just wondering have you pulled the plug and checked for fire. Iknow it sounds silly

[Burke]

Yes, I do have spark on #1, but it looked weak.

I do not have a choke cable at all. The one that came with the bike was FUBAR'd.

I did look at the #1 carb again and re cleaned everything including the pilot.

Today with new plugs I will attempt another start, hopefully my cable will be in as well.

[SHORTROUND]

use an old set of gutar strings to clean out the air pasages in carbs. works like a set of bendable files to get the gunk out. just an idea.

[Burke]

Got new plugs today, gapped them and put them in and bam! Fired up. Still ran alittle cool on 1 so I sprayd some carb cleaner in to clean her out a little more.

She idles around 900 rmp's, and will easily restart without the choke.
I'll sync the carbs next.