1 plug is running lean???

[gaffer77]

i have one plug which is running lean it is the right hand plug ,i havnt looked in the books yet ,just thought id get some info here first ,is it common ,will it hole a piston,is it carbs,air box inlets ,ignition ,fuel line or is it likely to be any or all of them

just wondered where the experts would start ,the bike seems to run fine any speed hot or cold traffic or motorway runs great really ,the more miles it does the better it goes (as in top end speed) it does have some rattles after a long run like the shimms but on the other side of the engine

i want to get it all done just funds and time are down at mo as my other bike has robbed me blind!!!!

[dragxs11]

If it's running ok, I'd wait for a good oportunity, and then dig into that carb. gaff. I don't know whether or not you've serviced them recently, but gunk in the fuel jets happens regularly here. Usually after a bike has spent some time sitting, but not always. As far as I know, the engine is pretty sturdy. I don't remember anyone killing a piston. If you do tear into it, look into the stock jetting on this site, and jetting tips, to make sure a P.O. didn't just throw in a smaller main jet cause he dropped the right one and lost it or something.

[John]

Before pulling the carbs, check for a vacuum leak. Use WD 40 or something not to flammable, and spray all around the area where the carbs attach to the intake boots and where the boots mount to the cylinder head. If the rpms increase, then you have found the leak. It may be a cracked boot, or an old, loose, brittle vacumm cap on the nipples on the boots. Could possibly be the vacuum lines to the petcock if the bike is a standard.

[dragxs11]

Good Point John! I hadn't thought of that....duh?

[gaffer77]

thanx you 2 i have some new intakes just wondering

what sort of nightmare they will be to fit also my bike does stand allot


also air filter would not fit so had to rip the foam off it and the right hand side doesnt close properly (air box top and bottom)

also found lots of dust in the box

changed the octopus with tube from a motor factor ,cant seem to run it thru without kinks


any help with these probs would be great

thanx again

[dragxs11]

The intakes are easy once you get the carbs off. I'm sure you can see that only 2 bolts hold each one on. And make sure not to forget the vacume advance hose. Both the K&N and the UNI filters don't fit very well. I just clamped mine down as best I could, but I'm sure thats not the best remedy. And I've removed my octapus thinking that it's like a third lock on your door. You have petcock valves, and float needles that stop gas flow, and a choke for starting(vs prime). I just didn't see the need for the extra complication. Some don't agree though.

[John]

I have found that I could eliminate the octopus, and use just one petcock to supply all carbs. I run at 65-75 mph for most of my commute to work and back, and I have never experienced a fuel starvation problem except the time I twisted it up to try a high speed run. It started to bang out at 110, and I never though to open the second petcock. I basically have a fuel line running between the two petcocks with a couple of T's in it to supply each set of carbs. The prime ports of the petcocks are capped off. After all, the petcocks will flow when in the on position. I have forgotten to turn off the fuel and found some gas in the oil and spill from the air box, but it has only happened twice. It happened more than that with the octopus installed.

[skids]

That is a good idea if you are not using the octopus. Then, you would have another "off" position available if the holey gasket was leaking at the regular off position...well, maybe...

Originally posted by John
The prime ports of the petcocks are capped off. After all, the petcocks will flow when in the on position.

[dragxs11]

Just FYI John, your bowls should not overflow gas into the airbox if your float needles and seats in the carbs are working properly. But you probably already knew that. Mine used to do that too, but after replacing those parts it went away. I haven't turned the petcocks off for a year or more except to remove the gas tank.
Improper float adjustment can also cause overflow.