My test ride wasn't great, can anyone spot the fault?

[chuck hahn]

1 oring kit from Robert will do the entire rack.

http://cycleorings.com/

http://cycleorings.com/VMkit.html

Read this on the intakes and measure the ID of the oring groove on your boots and order accordingly.

http://cycleorings.com/intake.html

[Wes51st]

Thanks Chuck, I really appreciate your help.

When I said not sure what to look for, I mean beyond he ordinary. I have previously used the guide you suggested and have rebuilt the carbs 3 times, each time just to make sure I haven't missed something. I've set the floats, cleaned every jet, checked all o rings and gaskets- all seemed fine. I've also bench synced them as per the manual.

Despite all this, because it was running better than I first bought it, something still isn't right. I guess I'm hoping for that one piece of "magic" advice where I go ahah, that's it! But know that's a long shot.

Thanks again, I'll look through all you sent just in case.

[chuck hahn]

Oh..Be sure the holes in the jets are all poked open with something like bread tie wire..and pay attention to the one down the center of the jets. If you hold them to the light and look down the end and cant see light they need cleaned and opened up.

And recently I had a problem with some carbs for my KZ and someone mentioned using Eagle One Wheel Cleaner ( be sure it says ETCHING on the label ) to drip into the passages. Well through that experience, I also found it does a great job of removing that residual white scale from the bowls and the bodies. I suggest using some and a toothbrush to descale anything that is a potential spec that could fall off and get sucked up.

Spray it on and wait about 15 minutes and scrub with the brush. rinse well with some carb spray and youll be amazed at how clean the fuel chamber will be.

[Wes51st]

I hate to say it Chuck as I'm so grateful for your advice, but I did exactly as you described- with the light, tooth brush, the works. Is there anything else you can think of? I'll give it a go if so, I'm just stuck on what else it could be.

Lets say the carbs are clean, new battery, new sparks, new fuel and the bike does run, albeit badly. Surely it must be the settings I have, but what I can't figure out is why it acts lean but still have black plugs?

[chuck hahn]

Recheck them......Like i said, there are all sorts of little specs that can dislodge and plug them up. if they are open its no harm no foul. Timing was mentioned and I must ask if youve done a vacuum sync with the gauges yet?? Are all the screws in the ports where the gauge adapters screw in?? Any fall out or loose??? What about valve adjustment...when was that last done???

[chuck hahn]

Is there an inline filter between the tank and carbs??? If yes remove it. Its a restriction to good fuel feed to the carbs and its not needed as there is a filter on the petcock. I have also got bikes and found the tank filter had come off the petcock and was rattling around inside. If that happens its a straight line shot for tank crap to get sent to the carbs...follow me???

[Wes51st]

Yes I do know what you mean. There isn't an inline filter and I've cleaned and rebuilt the petcock, it was fine actually. But I will take a look at the internal filter.

I don't like to ask but, anything else?

[chuck hahn]

Is the cam chain tensioner working right?? Could the cam chain jumped a tooth and threw the cam timing off? What bike and year is this gagin???

[chuck hahn]

See the manual for lining up the arrows and counting the pins. Gotta take off the cam cover but its something to check and eliminate.

http://zeus.mtsac.edu/~cliff/storage/gs/GS550_77-82_all.pdf

[chuck hahn]

Cleaned all the bullet connectors on the harness??? Checked the ground point from the harness to the frame..usually a ring with a black / white wire thats bolted at the front of the battery box mounting bolts.. Free of rust and the ring is solidly to the wire??? Grounds are a gremlin that can make some pretty interesting symptoms at times.

[GS1150Pilot]

You admitted that you were not 100% sure about the pilots. You could spend all day and then some if that is your problem and not get anywhere if you don't make 100% certain that isn't your problem.

[Wes51st]

Is the cam chain tensioner working right?? Could the cam chain jumped a tooth and threw the cam timing off? What bike and year is this gagin???

Okay, this is an new one to me, perhaps that has happened. It's a 1979 550e

[Wes51st]

Cleaned all the bullet connectors on the harness??? Checked the ground point from the harness to the frame..usually a ring with a black / white wire thats bolted at the front of the battery box mounting bolts.. Free of rust and the ring is solidly to the wire??? Grounds are a gremlin that can make some pretty interesting symptoms at times.

Yes all the connectors are good, I checked them when I fitted a new rectifier.

I still wonder if too lean is my problem. Would a 3/4 turn on the fuel screw cause it to become more lean then adjusting the air screws could balance out? I did have the fuel screw set to 1 turn, but kept finding sooty plugs, so backed it off to 3/4 when I next removed them.

[chuck hahn]

Plugs are probably sooty from running it on the choke system. On VM carbs the bottom pilot screw effects just the idle circuit. After that it transitions to the needle at about 1/8 throttle or so. You fine tune the fuel to air ratio with the side mixture screws. Turning them in will richen a cylinder and out will lean it. I set the pilots at 7/8 as the factory set them pretty lean to satisfy the EPA back then. This little gadget works great on VMs so you can actually SEE what the burn in a cylinder is doing.

Watch the video......

https://www.youtube.com/watch?v=9mKQvWM0nMg

[chuck hahn]

I would be sure the ignition advance governor is free and snaps back when you let go of it. Twist it till the weights are all the way open and let go of it. If it is sticky just sand the crank and the bore with some 1500 paper.