Starts But Won't Run

[RP#62]

Having trouble with the wife's bike ('98 Tourer).  Like a dumbass, I let it sit too long without fuel stabilizer.  Went to start it a couple of weeks ago and it started but barely ran.  Ran like crap at low RPM had to keep playing with the throttle to keep it running.  Smoothed out at high RPM.  Classic clogged slow jet symptoms.  I should mention that the last maintenance I had done was to replace the petcock diaphragm back in July due to the petcock leaking out of the weep hole on the bottom.  The diaphragm fixed the leak.

Fooled with it over the lase couple of days - charged the battery to rule it out (its only a year old) and it will start but only runs 2-3 seconds then dies.  Let it sit a minute and try again, and the same thing happens - fires right up, runs a 2 or 3 seconds and dies.  Doesn't run long enough to get up to idle RPM.  Bit the bullet and removed the carbs and cleaned the slow and main jets.  Mains looked fine but the slow jets were definitely clogged.  Cleaned them out by soaking in lacquer thinner and sliding a brass bristle (off of a wire brush) through them and blowing out with compressed air.  That worked - I can see through them now, so I thought I should be good to go. 

Put it all back together and it didn't seem to make any difference.  Fires right up, runs a few seconds and dies.  If I give it any throttle it dies immediately.  If I give it any choke it dies immediately.  If I try to start it with any throttle at all it won't even fire.  I don't think its battery or ignition since it fires right up.  Pulled the plugs and they look fine.  Just to rule out the petcock, I put the tank off of my bike on it and tried it again, but it didn't seem to make any difference.  I'm still leaning towards fuel.  Unless anyone has any revelations, I'm going to pull the carbs back off and strip them down to parade rest and clean everything.

-RP

[whitestroke]

Did you try fresh fuel?

[Grumpy]

Almost sounds like the needle valves on the floats are stuck in the closed position. That would not let fuel in and cause it to starve for gas.  Might try just tapping on the carbs with a plastic hammer to see it they will dislodge. Or could be the screen in the tank is gunked up with varnish.  I guess and easy way to check is to open a drain on the carb and see if fuel will flow out of it.

[Denny47]

What about the vacuum to the petcock, could this be the problem?

[donaldcc]

   please update on your progress.  want to hear the answer to this one.

[fudgie]

Kits bike did the same thing. I had to disassymble the carb and give it agood cleaning. After that it ran good but used seafoam/techron for 2 tanks and has ran ever since.

[Westsider]

How long did it sit?, sounds like quite a while. Curb idle circuits probably blocked, while carbs are removed to be cleaned,  remove all idle mixture needles , spray passageways with berrymans b12 , blow out with rubber tip air nozzle , repeat several times on each passageway. Berrymanns spray has always cleaned jets instantly to, for me anyway. While fuel tank is removed, remove petcock, drain , rinse out with fresh premium gas, throw away the stock petcock, install a pingle petcock, 1311ch, did I mention fresh fuel,
Happy new year, you will get it purring like it should.

The only time Ill run regular in the valk is when I know I will be on it everyday for a while,  Ive been told premium is a lot cleaner than regular and that alone sells me on it for a machine with six carbs.

I wish my wife could ride a tourer, but she had a very hard time keeping a 750shadow vertical.

[Patrick]

The boys covered your issue well. But. Have you checked the fuel flow from tank thru the carburetors? I'm sure you have a vacuum pump. Just pull a vacuum on the petcock and open the carb screws to see what happens. Also if you just cleaned the low jets, there is probably a lot of varnish still in the passages. Deep-Creap [spray Sea-foam] can be sprayed thru everything. You can probably get at everything without having to remove the carburetor bank again.

[Chrisj CMA]

also dont forget the petcock.......if its gunked up its not going to flow fuel like its supposed to

[Thunderbolt]

Sounds like you have covered most everything.  As Patrick said, pull a vacuum and make sure you get gasoline out all of the drain hoses.  I suspect that if you cleaned the jets, you probably verified that the floats are not stuck.  I always squirt carb cleaner through all the orifices in the carbs and blow them out with compressed air.  Sure sounds fuel related.

[RP#62]

Thanks for all the responses.  I really don't think its the petcock since I put the tank off of my bike (which starts and runs fine) on it and it didn't help but I will check as suggested.  I'll let you know what I find.

-RP

[Ricky-D]

For starters I would suggest to sit the bike upright to start it.

I would also suggest to drain each carburetor to insure they are getting fuel.

***

[Hook#3287]

When I had the corn fuel problem, I soaked and cleaned the slow jets to what I thought was like new.  When I put it back together, it ran the same, crappy.  Once I changed the jets to 38's, it ran great and has since, about 4-5 years ago.

[RP#62]

Fixed. 

Verified that the petcock was working (it was).  Took top off all carbs and checked that the diaphragms were good (they were).  The needles had a little crust on them towards the top at the fully seated location.  Cleaned them off and put the top of the carbs back together.  Drained all old gas out and replaced it with new gas.  Put the choke on and tried to start it - it started then died and I'm thinking crap.  Turned the choke off and tried it again and it started right up and ran fine.  Don't know if it was the gas or the needles or a combination of both, but its running good now.   That's good because I really wasn't looking forward to pulling the carbs out again - actually pulling the carbs is not a problem, its connecting those rubber boots from the airbox back to the carbs thats a mofo.

Thanks everyone for your input.

-RP

[Patrick]

Hmmm, interesting. But, good. Nice to hear its running again.

[Thunderbolt]

Resutlts=good.  Gunk on needles wouldn't be as suspect to me as the old gasoline, as they come into play later toward higher vacuum.  Once I put too much seafoam in one bike and it didn't run right until I dumped it and got fresh.  Glad she is purring again.  Thanks for  posting the results RP.