T140V 1976 Issues Starting. Need Help!

[Migsan]

Hi everyone
I recently did a complete nut and bolt rebuild on a T140V 1976.
I tried to start it first time and it fired up right away at 2nd kick. I did a test drive and after half a mile it started dying out on me and became really hard to start. I attributed at the time to the carbs running rich and having spark foul. I would clean the sparks plugs and it would fire up again. Eventually I noticed that I had some white smoke from the left cylinder and ended up rebuilding the top part of the engine again. Turns out I didn't aligned the segments properly on that side. Once I sorted that out the bike restarted again but when I would open the throtle and tried ride it it would die on me. It would also backfire mainly on the left side and seemed to flood with occasionally spitting fuel from the back of the carb. After that I hit a wall and could start it I would just flood the engine.
The carbs seemed well set with the exception of the old floaters and needle valves plus the needle jets were 210 while they should be 190 from the specs.
Ended up ordering new needles, needle jets, main jet and a stay up float kit and valve. Put it all back together and set the fuel level to 0.21´´ plus new set of spark plugs. tried to start it and again had back fire from the left cylinder but no start whatsoever. Checked the valves several times and they are in spec and also I have spark.
I am running the Boyer electronic ignition with a power box and battery. have the 11.9 volts on the battery.
Getting really frustrated with this and I am running out of ideas!
Any thing you can see that I´ve missed?

Cheers

Miguel

 

[grandpaul]

Your ignition rotor may have loosened off the cam nose.

 

[Migsan]

Your ignition rotor may have loosened off the cam nose.

Hi Paul

But if that would be the case would it spark consistently?

 

[speedrattle]

if you have a backfire you do have spark, but it might or might not fire, depending on the crankshaft position. boyers tend to either spark consistently or not at all. the backfire might be over-advanced ignition timing or an intermittent burn which allows wet fuel to accumulate until it backfires.

i agree with paul. re-set the timing on the ignition and see whether anything changes. check for a loose ignition stator or rotor before you undo either part.

 

[Migsan]

if you have a backfire you do have spark, but it might or might not fire, depending on the crankshaft position. boyers tend to either spark consistently or not at all. the backfire might be over-advanced ignition timing or an intermittent burn which allows wet fuel to accumulate until it backfires.

i agree with paul. re-set the timing on the ignition and see whether anything changes. check for a loose ignition stator or rotor before you undo either part.

That was spot on. Checked the ignition rotor and even though it seemed tight the timming was off. Tried and it started right away but it dies right after. I might have the carb floaters to low!

 

[speedrattle]

if i had a dollar for every time i have set ignition timing wrong i could pay someone else to do it for me.

if it starts and dies you may have the idle set too low. will it run if you hold the throttle open?

 

[Migsan]

if i had a dollar for every time i have set ignition timing wrong i could pay someone else to do it for me.

if it starts and dies you may have the idle set too low. will it run if you hold the throttle open?

No it wasn't holding the throttle so I tunned up the fuel level like half a mm and it worked like a charm. Also it's no longer drinking oil or smoking from the left side. Couldn't be happier
Thank you both for the help I was hitting a wall.
Now I can focus on the 69 Norton

 

[grandpaul]

if I had a dollar for every time I have set ignition timing wrong I could pay someone else to do it for me.

HA HA HA !!!!! I could retire!

 

[grandpaul]

Thank you both for the help I was hitting a wall.
Now I can focus on the 69 Norton

Of course, you are welcome; that's what this forum is here for.

We are NOT against posting Norton stuff here!

(just start a new thread, of course)

 

[Migsan]

Of course, you are welcome; that's what this forum is here for.

We are NOT against posting Norton stuff here!

(just start a new thread, of course)

Thanks

 

[speedrattle]

i want to see it. i have a 1970

 

[Migsan]

Still needs some work but 90% of the work is done