Confused...PLEASE HELP

The other day my 78 750twin started up on the first try. Now it won't start a week later. Good battery, good points/condenser, charging system good and coils. Only difference is I put on a new balancing hose, hoses for the overflow nipples on carbs and made new gaskets for float bowl screws. also put inline fuel filters on. Doesn't seem like the carbs are pulling in fuel, but I checked fuel flow in lines and is good, even put lines on without filters just in case...nothing, motor will crank but no ignition.


so I'm almost 100 percent sure that my float bowls are filling up and not emptying so no more fuel is getting in...any suggestions

78kztwin, check the connection for the wire comming from the points. It may have come loose when doing the fuel line revisions.

Good luck,
Jim

have you tried priming the carbs?

no how's that

If not done already, would remove plugs and hold them grounded against the engine while spinning it over and looking for fat blue sparks.

This will help assure adequate ignition power (but not ignition timing which should also be verified to specs using static method).

With ignition issues ruled out, would then consider possibility of issues with compression (including valve clearances), and/or carbs and/or fuel delivery to carbs.

Good Fortune!

im not sure with your bike but on mine i have a prime on my petcock. i turn to prime for a few seconds and pull choke and it starts right up but if you do have prime on petcock make sure you turn it off or it will flood the motor.

78kztwin wrote:

The other day my 78 750twin started up on the first try. Now it won't start a week later. Good battery, good points/condenser, charging system good and coils. Only difference is I put on a new balancing hose, hoses for the overflow nipples on carbs and made new gaskets for float bowl screws. also put inline fuel filters on. Doesn't seem like the carbs are pulling in fuel, but I checked fuel flow in lines and is good, even put lines on without filters just in case...nothing, motor will crank but no ignition.

so I'm almost 100 percent sure that my float bowls are filling up and not emptying so no more fuel is getting in...any suggestions

78kztwin wrote:

The other day my 78 750twin started up on the first try. Now it won't start a week later. Good battery, good points/condenser, charging system good and coils. Only difference is I put on a new balancing hose, hoses for the overflow nipples on carbs and made new gaskets for float bowl screws. also put inline fuel filters on. Doesn't seem like the carbs are pulling in fuel, but I checked fuel flow in lines and is good, even put lines on without filters just in case...nothing, motor will crank but no ignition.


so I'm almost 100 percent sure that my float bowls are filling up and not emptying so no more fuel is getting in...any suggestions

...new gaskets for float bowl screws---
What sort of "float bowl screws" use a "gasket" that can be hand-made?

...put on a new balancing hose...
Would double-check to assure integrity of hose and connections. If hose or connection is defective, intake stroke might be inhaling outside air through the vacuum nipples instead of inhaling mixture through the carbs.

Good Fortune!

Forgive this one :lol: but were the float bowl vent nipples mistakenly connected together instead of the vacuum nipples?

Good Fortune!

...new gaskets for float bowl screws---
What sort of "float bowl screws" use a "gasket" that can be hand-made?

...put on a new balancing hose...
Would double-check to assure integrity of hose and connections. If hose or connection is defective, intake stroke might be inhaling outside air through the vacuum nipples instead of inhaling mixture through the carbs.



the float bowl screws that cover the main jet...the gasket is handmade but I need to find a new material,,,any suggestions.

No eBay APP ID and/or Cert ID defined in Kunena configurationUncertain whether float bowl gasket is needed.

Carb kits are available at Z1E.

www.z1enterprises.com/detail.aspx?ID=299