Fuel flow problem?

[Johnna]

“Smokey” is a 1996 Yamaha g16 I purchased 2 years ago. It lived up to its name leaving a smoke screen James Bond would be proud of when it was running.

2 months after I bought it. I rebuilt the engine, it had broken rings and a bad valve guide. It had a full engine rebuild, new piston, new bearings, thorough cleaning, new valves, etc.

After that it ran great but a couple months later it started developing a starter issue. Bought a new starter, and well, it only runs backward so I put the old starter back on and live with the issues until I get the faulty new starter replaced.

The problem I am pulling my long grey hair our about is a fuel delivery problem. Smokey will start, run a couple hundred yards, and will sputter, stop, refuse to start (it cranks), it has spark, but the fuel filter is empty.
I have replaced:
1) carb twice
2) fuel pump 3 times
3) all gas lines
4) pulsar vent (it has a good pulse)
5) fuel filter 3x
6) pulsar hose (couldn’t find a vacuum hose to replace it so I used gas line)
7) all gas lines are well clamped
the carb vent seems clear.
9) cleaned the vent in the gas cap

I’m at my wits end on why this isn’t working as it should. I can’t think of anything else to try. The only other thing I can think of is the gas tank has a stripped screw where the port is to the connect the fuel line. Please if you have any suggestions I am all ears.

[chrisr32]

You did not specify if the fuel filter is after the fuel pump or before; if after, you may put one before the fuel pump to see if it is also empty when the one after is empty.

[Johnna]

The fuel filter is between the gas tank and the fuel pump.

[Dave in VA]

When it stops running, have you tried using starting fluid to see if it will start?

How are you checking the spark?

Does it startup again after it sits for awhile?

Have you checked the plug after it stops to see if it is wet or dry?

None of my fuel filters are ever full. They look empty most of the time.

[Johnna]

Yes it does usually start up after sitting a bit. I don’t check the spark plug every time it happens but when I do check it, it’s clean. (I forgot to mention I replaced the spark plug as well). I’ve never used starter fluid to restart it, as it will usually restart after a few minutes of sitting, or ‘tinkering’ with it like shaking the fuel filter, checking the air filter, making sure it has gas.

The fuel filter usually has a little gas in it when it’s running right, maybe 1/4 full. To check the spark I’ve pulled the plug out and put the wire on and crank it... you can see the spark especially in the shade of the garage.

The best way to get it started is turning it off, putting your feet on the dash, smoking a cigarette and feeding the horses a couple treats then try restarting it... it’ll run for short time after that.

[Dave in VA]

Use an inline tester to check the spark. Cheap from the parts store. Run the cart with the tester hooked up and check for spark when it quits. The spark should be bright when running.

What you're describing is a classic TCI/coil failure. Runs great, coil gets hot, fails, cools, runs great.

JN6-85640-00-00 T.C.I. UNIT ASSY

Search for the best price. Use the OEM Yamaha part. Aftermarket units are crap.

[Johnna]

Really? I never remotely thought it was an ignition problem I really appreciate the info... I’ll get an in-line tester for it in the morning. Thanks so much for the part number so I can find a good unit. 👍

[CP241]

IF you have to replace the coil, I would recommend partzilla. https://www.partzilla.com/product/ya...N6-85640-01-00


Amazon and ebay are sketchy about stuff like this, I've bought (and returned) more parts than I can count that were advertised as OEM parts but when they arrive, they're aftermarket junk. Partzilla doesn't sell anything aftermarket and they have pretty much everything.

[1arunem]

Had a similar issue on my son's G16. Run good, but after warm would not start. Let it sit and it would run again. Replaced TCI and never had that issue again <knocks on wood>.

[Johnna]

Holy moly. Lol put the tester on jacked Smokey up and wow .... yep thanks soooo vet much it’s the ignition. Much appreciate y’alls expertise 😁😁👍👍