Starting problems....need help.

Ok...So Yesterday I rode the the bike 3 miles down the road to the gas station. On my way there it died. I pushed the rest of the way and filled the tank. Attempted to start the bike and got nothing. It would crank and crank, but not fire. It tried a couple of times to catch, but popped and backfired a little and never started. Towed it home and started digging into it. Plugs are a little damp but not soaked and I've got spark. I used a screwdriver in the end of the plug wire with the screw driver close to the block to verify spark. Battery is fully charged. I'm kinda at the end of my rope right now trying to figure out what the heck is going on.....any Ideas ?

On a side note, the Main fuse blew yesterday and I replaced it with a 20 amp (like the label says) PO had a 10 amp in the main.

 

New plugs work wonders. Is this the fist time the bike has been running this year?

 

Forgot to mention I changed the plugs today. I Have ridden it 3-4 times this year.

 

Well I guess some more info is needed. Lets start with year, model, and location. Then, what did it do when it died (spit and sputter, just drop dead)? What have you done to it recently?

 

82 650 Maxim, Columbus Ohio. It just died. Sounded like it was sputtering, if I held the throttle down, it sounded like it might run, but if I pulled the clutch in, even at WOT the bike just shut off. Tried to start it, it just cranked. it popped and backfired a few times while I was attempting to start it. It would crank fine but not start. So today, I changed the plugs and checked all the electrical and mechanical connections to verify everything was looking good. Then a friend of mine stopped by tonight and we were looking at it and tried to start it. it cranked and fired for about 2 seconds then died again. He said "sounds like it's starving for fuel, so I checked the vacuum on the petcock and could feel it pulsing. So I plugged the vac line back in and pulled the fuel line. While cranking it dripped fuel and he said it should be pouring out. So I'm going to pull the petcock and fuel filter. I'll replace the filter, but not sure where I can find a replacement petcock locally. I stopped by a local parts dealer today for some other stuff and everything for the bike is either discontinued or special order. Is there a similar part off a newer bike that could work ?

As far as what have I done to it recently, not much. Rode it 3 days last week and changed the plugs this morning after I could not get it to start. The plugs were dark and not gaped properly (off by .3 mm)

 

did you check if you have good flow with the petcock on PRI?

 

Did you run way below where you usually run on fuel? You may have had something get into the line and clog it like rust, or if you've been using an ethanol blend, water and ether may have separated and ether evaporated away, you may have gotten the carbs all gummed up with water and gas. (They turn into jelly). Make sure the line and fuel valve is clear, drain the carbs and blow through the fuel line, Wd40 spray will remove water from gas with out taking the carbs apart, (just leave the bowl drains open when you do it.) It should run on wd40 but smoke like the devil till it all gets through. The benefit is you can use the straw attachment and blow out a few of the smaller circuits like idle and it won't eat your rubber diaphragms or if you have viton or nylon tips on your needle & seats it won't hurt them either. Don't be afraid to change the plugs, last week the NGKs were $2.07 each at Pep Boys.

 

Ya, check to see if it will poor out on PRI. If not, open the gas cap and try again, it could be the vent.

 

Flow is good on prime, that's how I drained the tank. On prime it was barely coming out of the filter So I'm changing the fuel filter today and going to try to track down a petcock. Padre - Thanks for the info, I'll drain the carbs and run some WD-40 through them after I change the fuel filter.

 

If the flow was good on PRI, then the petcock is not clogged. Change the fuel filter and try running the bike.

 

I had a similar problem when I first put my bike on the road. Turns out the inline fuel filter I was using was starving the bike for fuel. After I put a better flowing filter on, all was good.

If the bike runs on PRI, I would check your vacuum line to the petcock.

Also, consider you may have a blockage in the carbs. You might be due for a carb cleaning.

Good luck!