I have a 2000FLSTC 36k.
Have the bike 2 years, after tensioners cams, cam bearings and push rods (done by indy) she ran good, I did a little jet work and slip ons......best running bike ever. Always ran her dry when I knew she wouldnt move for a few weeks......always started right up. Suffered a back injury 2 months ago so stopped riding until I healed and forgot to run the carb dry.
Now the back is good but the old lady just cranks, a few backfires but no start at all
any suggestions what happened?
thanks

 

Clogged pilot jet. Pull it and clean it.Or replace if you don't have the means to clean it. It's the very end of the jet that clogs not the defusion side ports / holes of the jet. Probably approx..015 size or around that - so really, really small.

 

Start with the easy stuff... check for spark & fuel.. For now, I'd assume compression is good.

Since you report that it cranks fine, I'd do a quick check for spark at the plugs to eliminate a possible electrical problem.

With spark at the plugs confirmed, and compression assumed to be good for now, then it could be the fuel screen above the petcock is plugged, the vacuum petcock has failed, the line to the carb has delaminated and isn't flowing, or something (dirt/debris) settled in the carb and is blocking something..

The quick check here is to pull the fuel line from the carb, get a small jar, and see if fuel flows into the jar when you are cranking the engine...

If fuel flows into the jar, time to pull the carb..... or at least the pilot jet that Marlinspike described above...

If fuel doesn't flow into the jar, then work backward to the tank....

Before draining the tank to inspect the fuel petcock, I'd check the vacuum line from the carb to the petcock and make sure it isn't disconnected, cracked, loose, or split.. That would cause the vacuum petcock not to function properly.. Don't forget to check the petcock to carb fuel line. Make sure it isn't delaminated inside which could block flow... If it's OEM, it's pretty old..

If that checks OK... You'll need to drain the tank and remove the petcock. Then check that the petcock screen wasn't plugged by debris in the tank and/or the petcock itself isn't failing (bad diaphragm).

Good luck with your diagnosis, and report back what you find...



PS- My first guess would agree with MarlinSpike, but I tend to go through stuff front to back... it's my OCD and keeps me from jumping around..

 

Thanks Marlin Spike, its been a while since ive been in the carburetor. Can you tell me if the pilot jet is up in the fuel bowl or is that the bugger under thr aluminum plug I had to drill out. I should remember but at 75 things dont stay in the mind too long. I will check the shop manual as well
Thanks again

 

[QUOTE=hattitude;20640259]Start with the easy stuff... check for spark & fuel.. For now, I'd assume compression is good.

Since you report that it cranks fine, I'd do a quick check for spark at the plugs to eliminate a possible electrical problem.

With spark at the plugs confirmed, and compression assumed to be good for now, then it could be the fuel screen above the petcock is plugged, the vacuum petcock has failed, the line to the carb has delaminated and isn't flowing, or something (dirt/debris) settled in the carb and is blocking something..

The quick check here is to pull the fuel line from the carb, get a small jar, and see if fuel flows into the jar when you are cranking the engine...

If fuel flows into the jar, time to pull the carb..... or at least the pilot jet that Marlinspike described above...

If fuel doesn't flow into the jar, then work backward to the tank....

Before draining the tank to inspect the fuel petcock, I'd check the vacuum line from the carb to the petcock and make sure it isn't disconnected, cracked, loose, or split.. That would cause the vacuum petcock not to function properly.. Don't forget to check the petcock to carb fuel line. Make sure it isn't delaminated inside which could block flow... If it's OEM, it's pretty old..

If that checks OK... You'll need to drain the tank and remove the petcock. Then check that the petcock screen wasn't plugged by debris in the tank and/or the petcock itself isn't failing (bad diaphragm).

Good luck with your diagnosis, and report back what you find...



PS- My first guess would agree with MarlinSpike, but I tend to go through stuff front to back... it's my OCD and keeps me from jumping around..[/QUOTE
thanks Hattitude, you have helped me before. We can eliminate the petcock issues.....first upgrade was a Pingle Petcock 2 years ago. Having ridden a perfect running bike into the garage then 4 weeks later no start tells me gas issue. Gonna pull jets clean or replace......ill report back

 

check to see if mice chewed some wiring

 

Unlike a FI that is sealed tight from fuel pump to injectors and usually not a problem. Then, even the main tank can go fine for 6 months and still start.

You carb bike carb bowl has a direct vent to air.

It can totally dry out. Or be half full of unburnable fuel that's hard to get thru the system before motor gets good fuel.

Helps to cut fuel and run it to it stops.

See if you can keep it running long enough with fuel spray to hopefully clear it.

If not, check for spark. Remember, plugs must be in for it to spark, do use a test plug grounded to head.


Small Yamaha outboards have bowl drains on them. The treaded plug has a slit in threads so it only needs to be loosened a turn or so and drains bowl. It's designed this way since you can only get to them with a screwdriver. If everything was this well engineered, there would be a lot less problems.

I don't think most manufacturers want less trouble however. Sorta sad.

 

The pilot jet is under the float bowl cover and vertical position - forward of the main jet that is in the middle. About a 1/4" slotted screwdriver, no special tool required.

 

A quick way to do a flow check is to open the float bowl drain screw into a catchment and open the petcock valve. That is if your model has a drain screw. You will have to crank the engine to get vacuum to open the valve or use a artificial means to pull vacuum. But cranking would also check the to see if the vacuum is pulling it open and functioning.
Good flow, then its time to either look for mice chews or drop the bowl.
It's a little bit of a pain, but many times you can work upside down and drop the bowl to get to the primary jet without pulling the carb - if it's easier?

 

Sorry it took a while to respond my wife had me in Maryland.
I removed the S&S Stealth breather to take a peek into the carburetor. Twisted the throttle and a nice spray came from the jet. Gonna drop the fuel bowl to take a look and clean it up.
Before going to Maryland 2 weeks ago I dumped some Sea Foam in the tank (fresh gas) then cranked her to get in in the carb. Could I have unclogged the jet doing that?
Im very close to my neighbor so Im waiting for her to get up before trying to start. Hopefully a happy text follows that she fixed herself
thanks again for all your advice