Help Posible fuel problems

[markncarj1]

k kept blipping throttle till it died and pulled the plugs emediatly. they were dry. Im beginning to think it could be a bad acellerator pump. only happens when hot. maybe a pin hole in the pump?

[sportsterdoc]

OK, let's take a couple steps back.
1. Dry plugs generally indicates no/low fuel However, to avoid too many circles, check the battery voltage to be 12.6, pull the plugs, put them back in the boots, ground the ground prongs, crank the engine (kill switch in run). See if you have a good spark.
2. If you have good spark: Switch off, open ham can, crank throttle and look for a good squirt out of the accelerator pump nozzle. If only a dribble, then you have found the problem (or at least one of them)

I know that I asked this yesterday and you replied, but are you sure the diaphragm is fully lifting the slide and needle when the engine is on and the throttle held open for 1-2 seconds?

[sportsterdoc]

I am re-reading the thread and trying to reconcile your latest report with your post #9, 17 hours ago, which seemed to indicate a rich condition. Black smoke is incomplete combustion, which could be too rich or inadequate spark / spark at the wrong time (likely retarded). Is your timing plate secure?

[markncarj1]

LOL man my head hurts. much easier if the damn thing would just die!. i have had the aircleaner off and the squirt is good the slide is coming up. black smoke today as well but dry plugs. I am going to check the plate tonite. i will try to kill it with the aircleaner off and see if it is just running out of fuel. it does pop. i will also take the bowl off to see how much fuel is in the bowl when it dies. will the accellerator pump drain the fuel faster than the main circuit?

[markncarj1]

book says something about a vac canister? can i take the tank vent off to see if it helps?

[sportsterdoc]

Good idea: Run it with ham can off and do your throttle bliping. I'd laugh about your head hurting comment, but don't want to laugh at your expense!
The accelerator pump is more volume, per time, than you are going to flow through your jets. So, if the flow to the bowl is limited, or the float level low, I suppose a lot of bliping could lower the bowl level too much.

You stated that you replaced the bad petcock line, but are you sure the vacuum petcock is good? Did you pull the hose to the carb and check for good flow?

[markncarj1]

the diaphram seems to work i was able to move air through it. the top end is much better after i cleaned the petcock. i never did check the float valve to see if there is debris in it. I wish there was a way to bypass the diaphram in the petcock anyway.I may be able to take off the rubber oring off and remove the spling and maybe it will flow without vacuume. it is totally ok to laugh at me . i have been married 22 years so i am impervious to any humiliation!! lol

[sportsterdoc]

Your thoughts are in the right direction...anything to inhibit fuel flow
Is yours a California bike with an evaporation canister? If so, it is a charcoal bed which retains fumes to be sucked back into the motor. It should have no affect, unless a vacuum line to it is not intact.

I wish the info on each member had a check mark for California bike or "normal" bike!

If the cap vent is blocked, flow from the tank the the carb could be impeded, normally only at high flow (low uphill acceleration, high speeds, etc.)

Does that help?

[markncarj1]

cali bike. cant see the float being too low since it has ran great for a while now. anyone know any petcock tricks?
just thinking out loud. there is a T in the vac line that goes between the petcock and the carb. wonder if it is leaking? or maybe i need to go direct and disconnect the other side?

[sportsterdoc]

Confirm that the diaphragm pulls open when vacuum is applied?
How is it running right now? When you state "top end is much better", is that high speed operation?

Congrats on the 21 years. 41 years for me, next week. 12th grandchild was born at 3:10 this morning.