The worthless POS still won't start cold!!!

After all the cleaning in the carb dunk can, ultrasonic cleaner, drilling, compressed air, prodding and poking, the POS still gives 1 thump to get the head light to turn on then nothing but cranking when its cold. Cold as in 68 f in the garage this morning. What could it be? It started on carb cleaner spray after I re assembled the carbs. I let that slide because the idle ended up being set too high. My friend is selling his xj650 that is not in as good shape as mine. I will probably have to swap carbs and re sell the bike. I'd rather find out whats wrong with my bike and be done with it. I like how the "wonderfull" repair manual says to leave carb breakdown to a shop.

 

does it start okay with ether when cold?

 

First thing you have to do is calm down. Freaking out won't help.
If the bike's cranking okay then you know it's not the starter or battery.
Is it getting fuel? Are the carb floats set properly?
If your manual doesn't show you how to rebuild the carbs, get the Haynes manual. It's very good for the novice, better than the factory manual since it doesn't assume you know how to do everything. Getting the XJCD set from this website will also save you lots of grief. The Haynes manual is about 30 bucks and the XJCD set is 15 or 20. The Haynes manual will show you how to do a simple float height test without removing the carbs from the bike.
Are your coils working properly? There are a pair of easy tests you can do, shown in the Haynes manual, and they'll tell you if either coil is no good. You'll need a decent multimeter to do the coil tests. Half decent multimeters are about 20 dollars each.
If your coils are good, are you getting spark? The Haynes manual has a simple test for the spark plugs as well.
So calm down, get the right manual and tools and diagnose the problem step by step and ask very specific questions on this forum. Vague and general question won't get answered very much. Narrow the problem down and you'll get lots of help going that last mile.
thx,
baz

 

after the bike runs will the enrichener/choke lever make the idle come way up?

 

I guess that means a decent one will cost about $40? 8O

Hey I jest, because otherwise it just good advice.

Yup. Lots.

 

The bike starts on the smallest amount ether. You can shut it off 5 seconds after it starts that way and it will restart like it should. The float levels are all set right. It runs great. Idles good, has good throttle response, pulls to 9k. I just can't find out why it will not cold start.

 

Couple of questions - so when you cold start are you using full or partial choke? In the 40's mine likes full choke - at upper 60s half or less to start.

 

When you put the carbs back on did you connect the choke cable back up correctly. You may have hooked the cable up but the butt end of the outer case needs to be tucked into a brace for it to work. Try moving the choke and see if the mechanical slide on the carbs is moving...

 

The choke must be working beacause he said it will idle up when running and its turned on. I would start simple like put new plugs in it or take the plug wire caps off and replace or at least snip the wire and reconnect. i found that i could feel a shock if i touched my plug wire caps while the engine was running. i just re-did the connection and the problem stopped. no more shock. my bike starts fine though. low compression can make it start hard too. or flooding-try starting cold with no ether. then pull a plug and see if its wet or dry.

 

if it starts with ether, it sounds like it isnt pulling any gas in on a cold start.
lack of vacuum or something is stuck is my guess.

what happens if you push start it? do you have a hill to try it on?

 

Plugs are dry when it fails to start cold. It starts on carb cleaner spray. Just the smallest amount of that gets it going. The engine now does not speed up after its been warmed up when you add some choke. It sometimes speeds up then instantly wants to die.

 

I wish you hadn't already said you did so much to clean it out, because it just ain't gettin' gas through the choke circuit. You will have to eyeball those components for issues, malfunctions and faulty parts. The choke circuit! However, if the bike is a worthless POS, I would gladly drive over and trailer away your misery, No Charge! Bill

 

I believe the enrichiner curcuit runs through the bowl. it is a super tiny hole that goes through the gasket and out the little tiny opening in the side of the bowl. i had a very hard time getting mine cleared. took an all nite soak , a guitar string, pipe cleaners and an air compressor to blow them out. you should be able to squirt cleaner through it (watch your eyes)

 

Jim123 I gotta ask. . .
How did you verify that the jet in the float bowl, and the tube that sticks down were completely clear? No blockage?

 

ttr,
I used chacals drill bit to clean them out. Then I sprayed carb cleaner through them. They spent about a month in the gunk carb/parts cleaner. Ran the drill through again. Blew out with air. They spent 1 1/2 hours total in an ultrasonic cleaner with simple green, the machines heater, and hot tap water stopping every 8 minutes to rinse under the kitchen faucet and get blown out with compressed air. I also had a pen light shine through so I could see there was no blockage.
The carb bodies got the same treatment. I could feel air blowing out the top and front of the carb. Also, during the rinses under the faucet, I could see a solid stream of water comming out the brass tube when water was poured into the tops of the carb bodies.

 

Well, looks like I jump started the debate on your bike... You seem to be getting all kinds of good advice now. Anyway, don't give up on her. They're great bikes once you've got them running right.

 

Sure, that sounds like a great job, but after all that, some new junk could have floated down with the gas flow from your dirty old gas tank and clogged it up again. :evil: I just took my 550 carbs off for the 3rd time :x :? , but I get the bike running better, and closer to perfect after each try. Face it, the carbs not working. Last resort, take the carbs to a dealer shop.

 

Hey Jim,

This sounds like the same problem I'm having. If you start the bike on ether, let it warm up, and then kick on the choke for 20 or 30 seconds do the plugs come out black and way fouled with carbon? If so, then I'd say we're in the same boat and the choke mixture is TOO RICH (I know this might not seem logical, but its the best diagnosis I can come up with).

If you wrestle the carbs off again, I'd recommend checking the bleed hole on the enrichment tubes (see pic below). Use a laser pointer or a very small gauge wire to check. If they pass, then I'd double check your float heights. I'm pretty sure I've got my problem traced to crappy needle valves. I bought cheap aftermarket needles and they seem to get stuck sometimes.

Do you think there's any chance you enlarged the jets in the float bowls? If so, just try swapping out the float bowls with your friends carbs. If this fixes the problem then new float bowls are in your future.

Another school of thought is a weak spark. If the bike is cold and you take out a plug and lay it on the cylinder block do you get a nice, fat, blue spark? If not, then you should probably clean all of the electrical contacts, especially the brushes in the starter a la this thread

Hope this helps, and please let me know if you find the solution!
C$

 

Is that paint on those parts?

 

I'm not sure what you mean. These are the carbs out of my midnight maxim, so yes, the carb bodies are painted black. There is also a lot of grime, dirt, and rust in the carbs, haven't had a chance to clean them yet.

C$

 

I was talking about the greyish white stuff on the parts. Not the body.

 

Yup, them there carbs look overdue! :mrgreen:

 

Looking at it logically and the fact she is running so well after that initial start, it really does sound like something bothering the enrichment circuit. OK, the bowls and tube are free of stuff but how about the plunger circuits. I read what you say about the work you have done on these carbs however the plunger circuits can also cake up. Concentrating on the bowls etc., might leave us missing out the rest of the enrichment passages. Can't think what else it could be on the fuel side.

I speak with authority on this as my carbs have been apart (split) in the last couple of weeks and I could easily have overlooked those plunger passages what with my attention being on other parts. They *did* need seeing to.

 

I have an in line fuel filter. The tank looks clean also. Are those tubes supposed to sit in the taper of the starter jets? Maybe a po put the bowles on without gaskets(rtv) and pushed the jet or tube deeper into where they sit so when theres a gasket between the bowl and body, theres now a gap between the jet and tube?
I synced the carbs 2 days ago and been riding around the neighborhood. I adjusted the mixture screws by ear and got it runnung good. Yesterday I checked the sync and one carb was pulling no vac on the gauges. The sync was way off. I redid it and then used the colortune with the yics tool and found my ear tuning was a little off. This knocked the sync off so I did that again. Today it did not start untill I sprayed some carb cleaned spray into the intake. It smells like its running way rich. It was hot yesterday when I did the colortune and today its 20 degrees cooler yet it smells like its way too rich.

 

C$

That emulsion tube looks bent in the picture. Is it really bent? could that be a source of problems?

 

Vid 1 is after it sat for 9 hours. Vid 2 is after 5 minute warm up. What could be wrong? Note how the choke doesnt work well in vid 1 but works a little better in vid 2.
http://s89.photobucket.com/albums/k230/ ... IM0663.flv
http://s89.photobucket.com/albums/k230/ ... IM0664.flv

 

Well, today it needed carb cleaner sprayed into the intake to get it going plus a little choke followed by turning up the idle a notch. 69f and low humidity here today. I guess this is the way this bike will be for now unless it clears itself out through regular use. There was probably a reason it was 26 years old with 5800 miles on it and in near new condition when I found it.

 

I bought a 545amp Odyssey motorcycle battery to get my bike to start cold. If it rains the day before, i still have to use starting fluid to get her going. Its just the nature of the beast.

 

Not the nature of the beast. Should start, cold or not, fairly quickly or something is wrong!

 

Anything will start cold in Florida, Cubed. lol

 

Okay, how about this. If its above freezing it should definently start no problem. If its above zero it should start with full choke and little problem. If its below zero, start your snow mobile instead...

It should start cold no problem. Stand by that statement 100%. If it won't start without ether something is wrong. If it was ment to have to have ether to start there would either be an ether tank on it or a port for spraying the stuff in. What have you been doing all winter? Should have fixed the bike.

LOL

 

Agreed. It should start cold. Grant it these bikes are cold blooded and hate to start, but it SHOULD start.

Below 50 degrees I have to use full choke and a few tries but it does start. Above that I barely use the choke and it starts right up.

 

Dont get me wrong, these are great bikes but, Yamaha used the cheapest materials they could find to build these bikes. The nuts and bolts are like lead, they break off so easy. Is it possible that any age to these rudimentary carbs just makes alot of them ineffective in cold or damp weather?

 

I'll say it one more time. If it doesn't start easily, something is wrong with it.

I'll leave it at that and see if someone else wants to chime in with a +1 or a BS.

 

Chime It won't start easily for me!
Yesterday it restarted 9 hrs later after a 2 min warm up.
After it starts on gumout carb cleaner spray, if I adjust the idle to 1500 rpm, it will warm up that way and the idle will rise untill its warmed. After its warmed up, its now easy enough to reach down and readjust the idle. Before I shut it off I reset the idle to 1500. Lets see what happens tomorrow. I'll make another vid of it , too. I'm gettin real sick of this. My mustang has not been started in about 2 years. I'll dump a little 87 octane in the tank, put a freshly charged battery in it and make a vid of a real engineering marvel.
JK, I know there is something wrong with the carbs on this bike and the problem was there probably since day one!

 

Here is a clod start. Guess this is what I will have to deal with.
http://s89.photobucket.com/albums/k230/ ... IM0666.flv

 

Jim,

Have you tried cleaning up the contacts in the starter as described in this thread http://xjbikes.com/Forums/viewtopic/t=150.html? It may help, it may not, but it only takes a couple of hours tops, so I'd say its worth a shot.

Good luck,
C$

 

So it push starts and stays running when cold!

 

Wow. Fuel related, or possible weak spark. Does carb cleaner ignite easier than gasoline?

 

Open the garage door. :mrgreen:

 

Garage door is open 3 feet. Service door is propped open. There is good air flow through the garage. Seems like anything sprayed into the carb gets it going. Come to think of it, carb cleaner got it going when I first brought it home. I should have pushed it first!
I'll make a vid of the prob asap. Won't start with the starter but starts by bump start. That should be the first thing you think of when you're buying a bike that will not start? What really happened to my 5800 mile bike that caused it to be used so little?

 

Bad battery? All the juice is being used by the starter, none left for the ignition system. The spray start gets it going because it almost doesn't even require spark (sneeze at it the wrong way and it ignites). Probably also why it starts easy pushing it. How about when a known good battery is jumpered to it, still the same problem?

 

Re-read the whole thread and I'm definetly agreeing that it is electrical.

Evidence. Bump starts on gas. Starts with warm engine (easier to light warm gas than cold). Starts on ether and other products wich flame easier than gas). I believe it points to a weak/no spark. These bikes are known to produce weak/no spark on a weak battery and yet sound like they are turning over strong. Sometimes they'll catch when you let go of the starter button. When pushing, sparks would have full power of battery. So what to check.

Battery
Plugs
Wires
Coils


What else guys?