Okay, so got it started, but....

It won't stay started. I squirted some starter fluid into the mix and it will start up, but I have to be fully choked. It then will not start running for longer than (say) a minute or two at the most... If I cut back the choke, it will die on me, even if I keep it over rev'd.... I got it running by removing my spark plug caps and putting them back in. I am not so sure about it being an electrical issue, now, but I can't even tune it even if I did have my colortune because I can't warm it up and keep it running... Suggestions on what to check or could be causing this?

Fuel line clogged is the suggestion my manual gives me...

 

You need to have your Carbs Cleaned and Set-up to allow the bike to Idle.

Then, you need to do some Fine-tuning; after that.

The Carbs have a Pilot Circuit which maintains the supply of fuel to keep the bike running once it has been started.

I think we can safely say that there is a discrepancy preventing the bike from Idling without the use of the Enrichment Circuit.

There's all the machinations, additives and work-around measures soon to follow, as others suggest what you might try or do.

After you've spent the money on all that stuff ... you'll be needing several cans of Carb Cleaner and a Cleaned-off work bench.

Now Playing: This Summer's Blockbuster

"Meet the Mikuni's"

 

Rick, as usual, good advice, but couldn't this simply be an idle adjustment issue? I knew one guy that had a zx-11 and wanted me to look at it. It wouldn't stay on idle...it turned out to be a simple 1/2 turn of the idle adjustment knob, and that was that. I'd try and give that idle knob a turn while you keep it from stalling with the choke or the throttle.

 

From my reading of the Post ... It runs for a bit Enriched.

Give it a try ... what is there to lose!

 

The idle adjustment was my first idea. How high up should I have it? As a side note - who decided to put this screw in the hardest to get to place and totally difficult to turn??

 

Adjusted the idle screw, and no change (in fact, I can't even get it to start, now). Why would my carbs go bad in just two days of being not used? Cleaning my carbs is a long drawn out process. Let me ask. If my petcock is set to the "on" position, when I disconnect it, no gas comes out; is that correct? When I turn it to "pri" position, gas comes out the hose that does NOT connect to the fuel filter. Is this correct?

 

Assuming yours is the same as my 650 of the same year, you can leave the petcock (who named that thing??) set to "on" or "res" and no fuel SHOULD come out of it when you disconnect the hoses. These two settings are activated by vacuum when the engine is turning.

If your petcock is not functioning properly of course, fuel may escape when you remove the hose - so be prepared to stick it right back on if this happens.

The "pri" (priming) setting will allow fuel to flow freely without vacuum present. All 3 settings emit fuel from the same port on the petcock though, the second hose is a vacuum line which goes to the vaccum port on carb #3.

 

Yes, but on the 550, its on carb #2. Also, the fuel came out of the vacuum hose when I tilted the tank slightly to the left (where the petcock is)...

 

That was while the tank was in Prime, or another setting?

If it was in one of the other settings there should be no fuel from either port, and I wouldn't expect any fuel from the vacuum port even in the prime setting. I can't see how that could be intentional in the design.

It sounds to me like you may have a problem in your petcock, but I'll let someone more familiar with your bike confirm or correct me on this.

 

Yes, while in prime position. Rick?

 

No fuel should come out the vacuum hose even on PRI. I've never gotten into that part of the fuel valve but I believe this indicates that the diaphragm is leaking.

So, you can detour to fix the fuel valve or put together a work around to get it running. If it were me I'd do the work around, wouldn't be able to sleep at night until it was running.

Work around: Plug the vacuum line, cap the vacuum port it connects to and set the fuel valve to PRI. Verify that fuel does flow down the fuel line when on PRI.

Get 'er running.

 

Okay. First off, I was wrong. When set to prime, it comes freely out of my fuel line (sorry about that). Secondly, with the fuel completely disconnected, I can only get it to try to start if I spray in some starter fluid. It wont stay started (probably because I don't have a cap for my #2 vacuum hole). Is taking apart my carbs the next step, or do I have another place to look here?

 

oh, oh, I've got one. This maxim x that I have right now had an issue like this. It started with starter fluid, but then it eventually stopped even on that. wondered why there was a quart extra of oil in her. huh, funny thing, it was as thin as water, and stunk of gas. The last time it was started, (when I picked it up) the guy left the petcock on prime...it dumped a substantial amount of gas into the oil, thus thinning it out and I believe, not allowing for proper compression to occur. I changed the oil, and it started the very first time it cranked over. Just a thought.

 

Hrm... That's an idea, because (honestly) when I first got the bike, I left it on "pri" thinking that was the primary fuel, and "rev" was my backup. But I put ALOT of miles on it from then until now (like 500 I would guess). however, it sat for a few days on "pri" before this all happened. I will try and see. thnx.

 

The testing of the Petcock is child's-play.

Place the Petcock in the middle position for "Normal" operation.
Place the Vacuum Hose to your lips and draw a slight vacuum as if taking a ...
taking a ... hmmm (better go for Politically Correct on this one) "Drag on a cigarette.

Fuel should FLOW under vacuum.
Stop when there is no vacuum.
Taste bad if the diaphragm is leaking.

We have "Ignition" when Starting Fluid is introduced.
It quits when there's no supply of "Fuel"

Need something to do before commencing the removal of the Carb Rack.

Drain the #-1 Fuel Bowl
See if anything interesting other than gasoline comes-out.
Plug the Official Drain Outlet with a tight-fitting piece of hose with a bolt preventing anything draining out.
Fill-up a Rubber Syringe with Carb Cleaner.
Stick the Syringe in the Drain Screw hole.
Douche.
Pull Drain Plug.
If anything comes out that didn't go in ...

You could have had two racks of Carbs Cleaned by now!

 

Rick: what about mcrw said. Any validity to that?

 

I wonder how long it would take to ride from Boston to Bowling Green, KY?

 

Longer than you wanna try

 

Changing the oil never hurt a bike.
If you smell gas in your oil ... change the oil.

We have Officially started spinning our wheels; I'm afraid!

 

I was a'thinkin' that another run through the carbs would be a good idea at this point. The tweak of the idle adjust is a great idea too. Given that you have pulled and cleaned the carbs and that the idle screw yielded nothing, I'm out of suggestions (carbs are my weak point).

 

I haven't pulled and cleaned the carbs, yet... It was done for me before I bought the bike. So doing so can't hurt... Just not what I was wanting to do w/my Monday, but hey. Anything to get this damn bike running. To quote General Jack Beringer:

"GD it. I'd piss on a spark plug if I thought it'd do any good!"

 

Sounds like yours is acting just exactly like mine (550 also.) I've already pulled the carbs for cleaning once, and I'm now resigning myself to having another round of it. I had the same situation - PO said he had the carbs cleaned, but I found a lot of junk when I opened them up. And I know I didn't do as good of a job as I should have when I was in there. I'm pretty gun-shy of taking stuff apart now, since I managed to bugger/strip the heads of 3 out of 4 pilot jets while I was in there before, despite having a screwdriver that truly did "fit". I just made sure the openings were clear and went on about my business. I am going to pull the rack again and re-open the bottoms, but this time, I'm going to pull out the float valves and really concentrate on the pilots, etc. It will work - I just have to be conscientious about my cleaning efforts. (And I have to be stubborn enough to keep trying until I get it.)

 

If you cannot remove the slot-damaged Pilot Jets (Mikuni) ... then, use the appropriate sized cleaning tool from a Welder's Tip Cleaning Set and probe the Pilot Jet to be certain that its Metering Port is OPEN.

Then, you'll have to "Reverse Flush" the Pilot Jet Passage.

You'll need a Rubber Bulb Syringe.
Remove the Pilot Air Mixture Screw, spring, washer & O-ring.

Remove the Carb Top and Diaphragm (Hitachi)
You won't need to do this if you run Mikuni's.

Using the Syringe ... Slowly inject Clean Carb Cleaner in the Pilot FUEL Jet.
Block-off the Pilot AIR Jet with your finger.

Evacuate the Syringe and "Suck-up" the Carb Cleaner through the Pilot Mixture Screw opening.
Evacuate the Syringe into a clean coffee filter and look for contaminate.

Re-inject the Pilot FUEL Jet.
Block-off the Pilot Air Mixture Screw opening and "Suck-up" the Carb Cleaner through the Pilot AIR Jet.

Evacuate the Syringe into the filter and look for contaminate.
Obviously, if there's anything other than clean Carb Cleaner in the filter after flushing ... you must repeat the process until the Passage is Cleaned-out.

This process may or may-not clean-out the Pilot System.
When it works -- you get the benefit of having done a makeshift work-around for not having to Drill-out the Pilot Jets (Mikuni).

If your doing your own Carbs and you want to try to get back in-action without Drilling-out, ordering Jets and waiting for parts ... it's effective.

If your servicing Carbs for another party ... tell 'em to order-up some new Jets ... then, drill 'em out and blow-out the Passages ... it don't take much of anything to clog-up the Pilot Jet and Passages.

(The Pilot AIR Jet is external on Mikuni. It's the AIR Jet on the left-side of the Main Intake where the Airbox Boot clamps to the Carb Body.)

 

This is a pic of my XJ550 Mikunis, with the diaphragm pulled. Is that not the pilot air jet on the left side?

 

That's not the PILOT Air Jet

That's the MAIN Air Jet.