Startup problem

[Matt400]

Hey everyone,

I recently cleaned the carbs and re-jetted my 400. Since putting it all back in I have been having some problems getting the bike to start.

Before doing the carb it started up right away (but had fuel issues at high speeds hence the carb job). After doing the carb I cannot get it to start.
It has:
New premium gas as of today
Fully charged battery
New stock jets from a Yamaha dealer
New spark plugs
Idle mix screws are both at 3.25 (I read that most success is found between 3-3.5).

Does anyone have any pointers on where I should look next?

Thanks

 

[Sesty]

what year and model?
what pilot jet size?
what main jet size?
stock air filter?
stock exhaust?
timing set?
carbs synched w manometer?

there could be a number of things but without a ton more info its an impossible guess... when in doubt clean the carbs again yourself and take note of the jet sizing.

 

[Matt400]

So I've done more looking and it seems that there is an electrical issue causing it to not spark a good portion of the time.

I have not looked into the electrical at all yet but do you know where I should start?

 

[NewHavenMike]

I would start by making sure the plugs are sparking, then then check timing. You say you had fuel issues, i would tear it all back apart, even the fuel petcock and make sure its clean. Then make sure fuel flows freely out of the gas line and that fuel drains from the second carb

 

[alastairuk]

Usually when there's a spark issue I just immediately replace spark plugs, because they're like $3 and require minimum effort to replace. Then check you're battery has a charge with a mutli-meter, and that the battery is charging when the bike is running. Then check the points maybe. If those don't work, start replacing parts till you're broke.