Interstate Won't Start -- Clogged Carbs?

[Thrud]

I bought a 2000 Interstate in April and drove it about 50 miles home.  It ran perfectly at the time.  I've had the bike parked with the tank off since then while I was cleaing it up and adding some chrome.  Now, the bike won't start.  Engine turns over quickly but no dice.  I haven't performed a spark test, but I have no reason to suspect the ignition system.  I am thinking either the petcock or clogged carbs. 

I disassembled the petcock and everything looks good.  I will check fuel flow by running a tube into a gas can while I crank the engine to check the operation of the diaphram.

Am I looking at disassembling the carbs to get at possible clogged jets and/or stuck float valves?  I have a shop manual and the procedure to get at the carbs looks pretty involved.  Is there a shortcut where I can get some solvent (Seafoam or other) into the carbs?

Thanks in advance for your suggestions.

Steve

[jer0177]

You don't have a fuel pump - running the hose into a can that's below the level of the carbs while you're trying to start it won't do anything for you.

If you unscrew the bowl drain, are you getting fuel out of the bowls with everything in place (tank)?  If you are, then you're getting fuel to the carbs.  If not, you're not getting fuel to the carbs - and it could either be the needle and seat or float, or the petcock.  If it's 1 or 2 carbs that are no-flow, check those individual carbs.  If it's all 6, look at the petcock. 

These petcocks are vacuum operated (if it's still OE), so make sure you're getting a vacuum signal to the small hose that hooks up to the petcock when cranking. If not, check that hose coming from #6 intake to the petcock for cracks or breaks.

Did you pull the rear plugs to see if they were wet (flooding)? 

Was the battery on a tender while it sat?  Hondas are known for not wanting to fire (even though they're spinning) if they don't have a full charge.

[fudgie]

Battery.

[Jay]

Check the kill switch.  You may have bumped it to the off position while cleaning, etc.

[Thunderbolt]

It will spin like crazy and not fire if the voltage is like 10.5 volts at the battery while cranking.  Charge the battery overnight and crank it tomorrow.

[Thrud]

No fuel was dumped when I opened all six drain screws.  I'll check the plugs for wetness.  I'll also check the vacuum hose from #6.  My petcock is original Honda.  The bike's been on a Battery Tender all the while. 

Thanks for your suggestions!

Steve

[Challenger]

Valks will not crank over with kill switch in the off position, easiest thing is to pull a plug out, put the wire back on and crank it, if no spark, it's electrical, if you have spark, it's probably fuel related.

[MP]

No fuel was dumped when I opened all six drain screws.  I'll check the plugs for wetness.  I'll also check the vacuum hose from #6.  My petcock is original Honda.  The bike's been on a Battery Tender all the while.  

Thanks for your suggestions!

Steve

Open a drain screw on the LH side.  Now, take the vac line off #6 that goes to the petcock.  You can reach it with your mouth.  Suck on it, then stick your tongue on it like you do with a straw.  It better hold vac, or your diaphram is failing.  If it holds, keep it that way until you get fuel coming out of the drain line that you opened.  Sometimes when the bowls get dry, it is hard to get them full.  You are now assured you have fuel, and your petcock is opening.

I thought I had bad fuel one time, so I drained out all the bowls.  Had to do the mouth vac thing to get it to refuel, then it started fine.

MP

[Thunderbolt]

I would check the petcock again.  Pull a vacuum on the line to the petcock and it should hold, if it doesn't the vacuum side of the diaphragm has a hole in it.  With fuel in the tank, and a vacuum on the vac line, it should flow when the selector is in run or reserve, not on off.  Might as well pull the tank to check this, it will be a lot easier.

[fudgie]

Yea fuel wont flow without a vac. If it hasnt ran since april, 5 months, check the battery. Hook jumpers to a non running car and try the bike then.

[sugerbear]

my money is on the battery also.

[R J]

Am I reading his post correctly, the TANK is back on an hooked up, or does he have a jury rigged deal to supply gas?

Tank off, NO START is normal.....

If the tank is back on, the 1st thing I would try is to jumper it off of a NON-running car, truck, or what have ya.

PS:  Do you have the choke on full?
Have you been twisting the throttle in these trying to start attempts?

If you been screwing with the throttle, PLEASE leave it alone,  these girls do not like to start if ya play with the throttle and they won't keep running if you grab the throttle before she is ready.

After you have tried these, repost and let us know what results you had.

[Thrud]

The bike's been on a Battery Tender for months, so starting current is not an issue.  Motor spins very rapidly.  I don't suspect the ignition system at this point.  I do have a spark test as a backup plan.

I engage the choke fully and do not move the throttle, so as not to flood the carbs.

Tonite, I'm going to set the tank on a workbench, put some more gas in it and test the vacuum through the petcock.  If I apply some vacuum to the petcock via the hose taken off #6, then a properly functioning diaphram should allow gas to flow into a gas can, right?

If this works, then I'm looking at disassembling the carbs to check for stuck valves or clogged jets.  Am I on the right path?

Thanks,
Steve 

[Ricky-D]

Although the battery has been on a battery tender for a long time, the only way to check it is with a volt/ohm meter.  The motor will turn over pretty fast with a poorly performing battery when comparing it to experience with other starting systems and motors.

Turning the throttle will not flood the carburetors (cylinders) since there is no accelerator pump in the Valkyrie carburetors. A little blip with the throttle while starting is the way I do it and that practice has never failed me.

***

[Richythebluesman]

Thrud,
Save yourdelf some time ... leave the tank alone.  Open the carb bowl drain screws one at a time.  There should be fuel draining from the fuel drain tube.
How old is the gas?

[valkyriemc]

Thrud,
Save yourdelf some time ... leave the tank alone.  Open the carb bowl drain screws one at a time.  There should be fuel draining from the fuel drain tube.
How old is the gas?

True, if no fuel comes out of the carb/bowl drain tube under the bike, means no fuel to start either... Good advice on getting vacuum on the P/C to get the gas flowing or check for flow.     

[rodeo1]

your chances of sticking all 6 needles and seats is slim to laughable, i have worked on them that have sat for several years and had no stuck needles and seats. the jets can clog pretty easy when left with gas in them for extended time, but again, all 6 is really rare, i have never seen that. if you have a bad petcock and it just simply shut down and won't allow gas to flow, then you have found your problem, rebuild the petcoc and go from there. i have also never seen a coil go south on a valk, so i wouldn't be looking too seriously at electrical. sounds like no fuel to me. but then i'm a republican with independant political views.

[R J]

Do us old farts a favor would you please?

Try starting it with a vehicle that is not running.

If it starts then your battery is fried.
If it no start then look at the petcock.

Put a kit in it and try again,

NO start, come back and give us a rundown.

Thank you for your patience and listening to old timers who have been there and done that.

.

[Jay]

I think your Valk is worn out.
I'll make you a good deal on it 

[Thrud]

Naaah!  You wouldn't want it.  It's got only 17,082 miles on it! 

[Mr.BubblesVRCCDS0008]

Do as the old timers say. If your go cranking on a battery long enough to get the vac. to open the petcock and get fuel to the carbs your battery is going to be weak if not too low to start the bike.  If you hook it up to a spare car battery or a non running car then your cranking time will be good enough to get fuel to the carbs. Also make sure your getting the choke all the way down. The first hard spot is when the cable slack is taken out the next hard spot is when the choke is fully engaged.  If I were trying this I would pull the headlight fuse to also help the battery life until it cranked.These bikes will turn over like a sewing machine with less that 10 volts but the coils won't fire at that voltage. Good luck and keep us posted.

[Cruzen]

While I have never had this problem with my Valk.  You might try what we used to do with multiple carbed car engines.  Grab the throttle and twist it all the way open.  Then hit the starter while holding the throttle all the way open and let it spin.  However having suggested that, if it starts you have to quickly release the throttle because once it catches it will rev quickly.

[longrider]

Thrud

I live in the frozen north and winterize each year by draining the carbs among other things.  When I get it out in the spring rather than spin the motor over for a long time on the starter (hard on it) I pull the vacuum line of #6 and pull a vac on it either with a brake bleeder or just suck on it and draw a vac for a couple of minutes  (need to breath now)  then check for fuel at the bowls,  if you do have fuel it will start.

warren