Bike still not ridable...

Ok, I replaced the alternator brushes, they were 9mm and needed it. Bike still dont run right, I can start it with starting fluid, and it will run as long as I keep the throtle above 3000 but when I drop it down it will slowly die and I cant recover it. This sounds like to me like there is something wrong with my pilot circut, because if I understand right, it runs on the main jet at higher RPMs and pilot jets at lower. Ive tried the mixture at all different settings from 1 and 1/2 out all the way to 3 turns out, It doesnt seem to matter, it still wont idle, or start without starter fluid.

Things that I notice that might be of concern:

My carb boots on the airbox side have loose clamps, clamps are tightend all the way but still are loose.

My battery has just a couple tries on the starter before It is dead and barely moves the starter motor. But the bike does the same thing when hooked to a car battery.

the starter (or engine) sometimes makes a wierd noise when trying to start the bike hard to describe its kinda like a buzzing noise.


I have cleaned the carbs (went through them twice) all passeges in the pilot circut are clear, I bench synced them perfectly, and have tried different mixture settings.

What else would cause the bike to die like that at low RPM?

 

Hey! You're back. Hope the move went well. Where did you end up? Still around Olympia or somewhere else?

 

You might have to dial your carbs in more while they are on the bike, if you havent synched them with the motor running then I dont think they are synched enough to ride the bike. Mine was running the same as yours while it was just bench synched. That only gets them close enough to run the bike so you can synch them. If they are too far out of whack, then the bike will not even run, or it will just be that much more difficult to synch them.

For the pilot screw adjustment, if you dont have a colortune plug, then just bench synch them, 2 1/2 turns out I think, and then run it and look at your plugs. Turn them in to lean it and out to make it richer. If they are black then they are too rich, whitish then too lean. I guess it is harder to tell with the gas nowadays (as I have heard), and if you are having trouble, then just set them too rich and then turn them in, very slowly-by 2-3 degrees each time, until they look good.

Edit: You want to synch them on the bike, then get the mixture screws set, then re-synch them! Good luck, I get to do it tomorrow, change a shim I made too loose!

 

You may not have enough juice happening to run the bike if the Battery is almost dead.

That's part and parcel of what is going on with your starter; too.
The juice from a 9 Volt Smoke Detector Battery will close the Comtacts on the Solenoid. But, the Main Starter Circuit needs some BIG Amps and it sounds like your Battery's Big Amp days have passed by.

New Battery
Close the Air Leaks off.
You may need some Carb work if you can't get the engine to run on the Pilot Mixtures.

I'd say ... Bring the Piolt Screws Out to just shy of 3.0 Turns and see what happens.
If the Bike won't go with a new Battery and Pilots set Rich ... you'll have to have the Carbs worked on.

 

I'm going to follow Rick up and suggest replacing the battery, it's shot. A bad battery will make starting nigh impossible. The loose clamps on the airbox boots will lend themselves to a no idle condition at less than a few thousand RPM. Loosen up the airbox assembly (three bolts/screws as I recall) and shift the assembly forward while guiding the carb intakes into a square seating in the boots. Tighten the clamps and the airbox hardware and see if that doesn't help.

 

Buy a new battery.

Also, buy a Battery Tender to keep it in top condition. It's a great investment, only $29.95.

 

I understand I do need a new battery. But when I hook the bike up to a car battery I get more starts out of it, but it still wont start on its own and wont idle on the car battery, wouldnt a new battery act the same?
(somethings telling me that my carbs are shot).

Gamuru: I'm back temporarly, because I am borrowing an internet connection. I moved to the other side of olympia, Black lake area. The move went well, but all my stuff is burried in a storage shed, you know how that goes.

 

To answer your question Energi2er, yes. A new battery would act the same but you would be able to eliminate it as a cause. I would look at your carbs right off the bat. Sounds like they are not getting properly sealed off.

 

Carbs don't get "Shot' ... they're Aluminum and Brass -- for the most part.

You just need to have them Cleaned-out, Clean-Tuned and Pre-set to make the bike run.

Then, after some precision tuning ... you get them "Dialed-in" and can forget abort them for a little while because they won't be the source of your headache anymore.

 

I think I have found the problem why it wont start. It needs a pilot circut in good condition to idle correctly. All my pilot jets have screw driver damage. If I understand correctly the damaged jet will not let the exact amount of fuel through the metering port, its either too much or too little. and the mixture adjustment doesnt matter with a damaged jet. Soo. I am in the process of ordering new jets to see if that is the problem.

Any comments?

 

Do you mean something like this?

This bike runs just fine.

For what it's worth, I was able to pull that jet out with locking pliers.

 

hmmm. Float levels then??

My drain screws are stuck...

 

Micarl, What engine are you running with those carbs in the pic? and what is your mixture settings?

 

1982 XJ650 - Same engine you have.

My mixture screws are ~ 3 turns out. I can't seem to get mine to go rich. I'm thinking I either need butterfly shaft seals or some PO did something to the air jets.

Your thread is getting so long I'm not sure I know where you stand. Are you getting it to fire on ether, propane or the enrichment circuit?

 

propane: yes, enrichment circut: no

 

ether: yes

and it runs at higher rpms after I start it with ether. But dies out when tries to idle.

 

Have you checked your enrichment circuit JET deep down in that little passage in the carb BOWL......that's where the (non-removable) starter jet lives.

Every single used set of carbs I've gotten have at least 3 out of the four starter jets clogged, usually plugged tight. If they're plugged, the bike won't respond to choke, and won't idle without it for the first few moments (until the engine warms up and doesn't need the enrichment circuit operating).

It's damn near impossible to clean the jet (and it's a good idea to clean the drop-down siphon tube in the carb body that accesses this jet) if it's plugged tight without that special little drill bit that I sell.

To tell whether your starter jets are clean, you'll have to pull the bowls off. What you should see---if they're clean---is what is in the picture titled starter-jet.jpg (about 2/3 of the way down the page). It's the best example I've ever seen and using the "pen-light" technique is the only way you'll be able to tell properly (hopefully your eyes are good!):

http://www.xjbikes.com/Forums/viewtopic ... rt=15.html

 

Fuel Bowl Bottom and Starter Jet Well getting Fuel?

Siphon Tube Open and allowing Fuel topside?

It don't take foreign matter to clog the tiny Metering Jets to that Fuel Bowl separate Well for the Start Jets.

The same for the Siphon Tubes. Some models have tiny holes along the sides of the little brass tube. You need to punch those out and probe the Siphon Tube to make sure you are getting some Fuel up to the Enrichment Valves.

 

done all that, starter jets clean, (can see light through them, and they shoot a good stream of carb cleaner through them) Siphon tubes are clean, I flushed them, and back flushed them with a bugger sucker. Its all open passage from there to the enrichment valve.

 

Micarl: How many of your pilot jets have screw driver damage? just that one in the pic? "ALL" of mine are chewed up, Could that possibly be the problem at all?