Problems Starting

Hey everyone, i'm new to the forum and have purchased a 82 xj650. I've rode it to work about 3 times total round trips about 120 miles, and I have experienced no issues at all.

Just today I tried took it out for a short ride and parked it in the driveway, about an hour later went back out and tried to start it.. Bike would not start, i messed with the choke and still nothing. Finally it sputtered back to life and ran fine. Took the bike around the block and had no issues, turned it off and tried to start it again - Same thing engine turned but no ignition

Any ideas why this would be happening. once it's started it seems to run fine

thanks

 

If you are getting fuel then I would start with the cheapest solution, get new spark plugs and make sure your battery is fresh and strong, most acid based battery for cycle do not last too long (2 years max) especially in the colder region

 

Does it make any sound at all? Does the starter motor crank?

If so, I would suggest to check the petcock and the float levels.

If the petcock is on PRI, then gas flows freely to the carbs and it is up to the floats and float valve to stop the fuel flow. If they are set too high or if the float needle/valve aren't closing properly, gas will flow into the engine and/or airbox and/or crank case. If it goes into the engine, it will foul the plugs and flood the engine. Try this: remove the plugs and then light a barbeque lighter in each of the cylinders. If you get a nice "poof" then the engine is/was flooded and you probably need new plugs. You might be able to restore the plugs by cooking them with a propane torch, but your best bet is to buy new plugs.

**But** before you try to use them, check your float levels and the float valves. They had to be bad or your engine wouldn't have been flooded, whether the petcock needs work or not.

Now, if the petcock was on "ON" or "RES", then no fluid *should* have flowed through to the carbs. Try disconnecting the fuel line and the vacuum line and see if fuel will come out when it is set to ON or RES. If so, then you need to rebuild the petcock.

So check those things before fouling a new set of plugs.

See if you can give us any further info as to what exactly is happening.

Silly question, but the kickstand is up, right? It isn't supposed to start if the kickstand was down.

 

The first thing I'd do is Clean and Lube the Sidestand Switch and Linkage.
Dirty Linkage will hang-up and cause NO Starts.
The Guts of the Switch might need a squirt of Electric Contact ReNu ***

*** Radio Shack

 

I was not aware that the kickstand would cause a no start. This is because i've always started it with the kickstand down and had no issues.

The engine will turn over and fire up after I crank on the throttle while starting. then it runs fine, the last tank i rode with the petcock set to ON and had no proplems, i'm not really sure what the difference between ON and PRI are? aren't they both the same.

Rick are you talking about the kickstand switch?

Thanks guys i'll try some of this out tomorrow afternoon and see what I get.

 

Oooooh my jesus NO You did NOT! ON and PRI are NOT the same! Check your OIL! You're gonna KILL your bike!!!! Smell your crankcase and see if it smells like gas. If it does, change your oil PRONTO! Oil filter too. Run some seafoam in it for 50 miles and change the oil AGIAN!
PRI means its PRIMING your carbs. If excess fuel gets into the carbs it leaks into your airbox. After your airbox it leaks into your crankcase!
Holy crap dude
-SLKid

 

Finnan21,

As SLKid said directly and I said indirectly, PRI means PRIME. This is what you do if you just put the carbs back on and they have no fuel in them. You set it to prime and it allows the free flow of fuel until, if everything is working perfectly, the floats rise to the point of the needle valve closing, shutting off the flow of fuel. If the floats are not set properly or if one (or more) of the needle valves does not close properly fuel will be allowed to continue flowing. it can go two places: through the carbs to the engine or into the airbox, soaking the air filter, and going down the vent tube to the crankcase (thereby ruining your oil and leading to excessive engine wear).

The ON and RES positions will only allow fuel to flow (assuming the petcock is functioning properly) only when there is vacuum in the vacuum line coming from the manifold intake (usually from the #3 intake). That is why I said that if you detach the fuel and vacuum lines with it set to those positions, you should get no fuel out of the tank. If you do have fuel come out when on ON or RES, then you need to get a petcock rebuild kit. Until you do that and get it installed, trying to run the bike will be a waste of spark plugs because you will keep flooding the engine and ruing them, as well as risking a possible fire if fuel goes the other direction ...

You may, however, have found the solution with the kickstand bit. There is a sensor/switch that, when the kickstand is down, the bike is not supposed to turn over. From your comment about turning it on with the kickstand down (if I understood you properly) then that switch is failing intermittently and you should try to start the bike with the stand up and see what happens. It should start then.

This is why I asked about more detail as to what happens. If you try to start and get silence, then that is one type of problem, probably the kickstand switch in this case. If it tries to turn over and start but never catches, then it is another type or problem. We can't know until you tell us.

 

SLKid I only asked the differance between the two I have not run the bike with the petcock set to pri only ON and RES but just to make sure I checked my air filter and took a sniff in the crankcase, no gas.

Anyway let's start over here, I get on the bike turn the ignition key to on, then flip the run switch, and push the button.. Starter is engaged and turnes the engine. No start. Try again - sounds like it wants to start but untill i twist the throttle while it's cranking it won't come to life. Push start - twist throttle ... Ignition!!! now I have to rev it a few times to keep it started, after that it will idle around 1,200rpm or so. It will stay running untill i turn it off, then it's back to the step one of this paragraph.

So I'm going to check the petcock and spark plugs this afternoon and i'll post my findings, also i'm going to see if the battery might be dying and give it a charge.

Please understand I am not a motorcycle mechanic, this is only my second bike (before this I had a 1969 Honda CB350). I have purchased the Hayes manual for my XJ650 but it's really vage in my opinion as to details regarding troubleshooting.

 

Finn,

Could you put what bike you have year, model in your signature. (shows up on the bottom of these posts) Would be helpfull for us guys that have similar bikes.
Now back to your problem. It sounds like to me you have a bad electrical connection in the switches that you are moving. I think your useing the kill switch on the right handle bar to stop the engine am I correct? Then you turn your turn the ignition switch off when you stop. SO now when you want to start it back up again you turn the ignition switch on then flip the kill switch to run and then you try to start it?? Is this correct. If it is we need to know two things. First try not to use the kill switch at all just use the key switch. Second Need to know the battery voltage when you are cranking it over. Thanks

 

I sometimes have a similar issue. If out on a ride and stop for 10 minutes or so bike acts like you noticed. Only happens rarely and did it once yesterday on a brief stop. I'm going to try this next time. Turn petcock to prime - wait a few second then start her up and petcock back to on.

I have noticed what you have - gas and crank and she fires and runs fine. My theory at this point is it happens when I pull in and shut down quick leaving bowls at a lower lever. In ON the gas is shut on/off by vacuum.

But this is only a theory - the starter jet sits very low in the bowl. Problem is this happen very rarely for me so will be hard to test. If this is happening a lot for you and my suggestion works you may have some fuel flow issues.

 

Are you using the choke?

Watch the choke cable move the carbs. Do the plungers go up and down as you move the choke lever back and forth?

 

here are my findings -
1. spark plugs are free of carbon build up - alittle black but normal color for spark plugs.
2. Fuel doesn't flow from petcock when ON - RES but does flow through on Prime
3. No gas overflow in crankcase or inside air filter.
4. The kickstand switch doesn't work (as in it's disabled, as far as i can tell but the bike will start whether the switch is engaged or not).

I cranked it over about a dozon times this afternoon and it started fine each time.. Bizzar behavior if you ask me, i'll test your theroy tomorrow on my way to work Bill and tumbleweed yes the plungers all move in sync when I move the choke.

I guess the only other questin is do I need to use the engine kill switch when I park the bike or just turn off the key?

 

"A little black" is not a normal color for spark plugs.....it either means:

a) too rich of a fuel mixture, or......

b) if they are greasy/oily, then oil is being drawn intot he combustion chamber somehow.


Proper combustion conditions will result in a barely tannish-brownish color on the insulators.

Pure white is too lean, and will cause overheating problems (i.e you will burn a hole in the top of your piston eventually). Up until that time when your engine does self-destruct, though, it will run great!, as engines perform a little better under a slightly lean fuel mixture condition.

 

Well at this point I think i'll take it to a mechanic and have him overhaul the bike. I don't want to cause any harm to it due to my obvious lack of knowledge to motorcycles.

Anyway thanks for all your advice

 

Just make certain that the shop really knows about older bikes and how to service them. Lots of people will say they can when they really don't have a clue. Take the PO and his shop of my Maxim X: they told him the bike needed a new CDI when it doesn't have one and the TCI isn't at fault because it can turn over. They got $300-$400 out of the guy and he still didn't have a working bike. Criminal.