Paul's Yamaha 3MA track bike

[Paul]

hi edd
okay we'll talk more over the weekend
i have to give up now, i have to much to sort out today to leave tomorrow
i will try the airjet at 1mm
here is a video this morning
you can hear it a little when i first start catching up to the white truck, watch rev counter as i coast after accelerating you can hear it just before it starts to come to life again
then seconds 49-52 and 55-57 after i turned around, then its doing it for a long time, 3 seconds each nearly.

ideas:
34mm 3MA-20 carbs
airjet, as edd noted
carb slide, 0.5 std 3ma1
mains are 230/240
pilots 30
airscrew 1.0
needle 6L4-63 second from being raised completely
powerjet 90
float level 19mm

http://youtu.be/zvNygtghn4U

[Paul]

1.00 airjet tested today
Hesitation still present.
I'm going to retard timing around this zone 8500 upwards.
Only thing I can think off.
Why would it hesitate on reopen ing throttle? Come on lads. I'm losing the plot now.

[Louis]

I'm still thinking .

Looking to the movie.
Would say that it could be electrical, if it was fuel starvation I doubt if the engine could react that fast (to get the fuel bowls back on level)

Is it possible to put back the original ignition easy? (just for testing of course)

[EEKNOWS]

Sounded like it was running out of fuel to me.

[Neal]

Is this running with the sugo carbs ? Does the bike idle ?

[Paul]

Lean needle?
I'll investigate
They were sold to me as sugo, Neal you saw the advert.they are marked 3MA-20
No bike does not idle.

[Paul]

Did some work
Raised the needle, it is all the way up.
Made the top of the carbs seal better where TZ cable now goes in
Running a 1.0mm airjet now
Made the carbs idle now
Balanced them again
Retarded timing where it occurs 8500+
Damn thing still hesitating.
Almost worse now or for longer.
I'll try advance the timing.
I'm also running out of ideas.

[Louis]

Paul,

I still stay behind a electronics problem (after seeing the movie)
(But, can have it wrong of course)

My perspective, a empty bowl or fuel starvation is not giving you that fast your power back.
(It takes time to get the fuel back)

If you like to feel fuel starvation, just turn the feel tap on off will driving, when the engine starts to stall/stop open the tap, and you will feel how much time it takes to get full power back.

Can you mount a small multymeter on your tank, perhaps your charging system is given a certain peek power and the ignition turns off (for protection reason) or low power. just a idea
-Try a other ignition coil

Imported (to me)
The signal for the rev counter is it coming from the coil or is it coming from the prog ignition?

[Paul]

Hey Louis 
I want to believe its electrical. I have tried every fuel option/combination I can think of.
Rev counter signal is from coil, zeel has a orange wire to coil and as far as I can recall this is linked in the loom to rev counter.
What must I connect the multimeter to? The battery terminals?

[Louis]

Ok, I had hoped that the signal is coming from the cdi unit.
When you have your problem, the rev counter is still active (and not dropping)
This means that the cdi sees the pickup signal and is given the ignition pulse to the coil and tacho.
The tacho is still working, but does the coil work?

If you have lying one around, try a other coil.

Specially if you say ''it does do it more now then it use to be''.

[eyrey1]

i hope you find whats up with it paul as my 3xv is the same !
im going to drop the needles on notch this time , if i sort it ill let you know

[Paul]

i hope you find whats up with it paul as my 3xv is the same !

I know, i was hoping you'd beat me to it.

Louis, I think I do have a spare 3ma coil. I do have single 3xv coils. Can these be adapted? Split the orange wire?
You say not fuel but when rolling the throttle back open if I close it slightly and carry on opening it comes back to life. It's like the air rushing through the carb 1. isn't sucking the fuel or 2. sucks too much fuel. I can't tell which.

[Paul]

Just thinking. After listening to myself, I am running 0.7mm power jets. Do you think at the higher revs where it's working nice after being drawn on by natural acceleration they work great, then chopping and opening throttle causes a delay? Std PJ for 34mm carbs is a 10.

[Paul]

hi lads
this is dragging on somewhat i know  , but some of you might still be slightly interested....

tried 30 powerjets and still the hesitation

decided to try the 32mm carbs, still the hesitation
maybe not as readily on lower revs but badly on higher revs
so i pulled the pods off to see if it wanted more air, it would hardly go, it prefers the pods

i can only report findings, i am lost. unless the head volume is too small ie too much compression. wht the #$%@@ would it hesitate?

[Louis]

Have you tried a different coil?

Also look closely to what type you have mounted.

-3MA00 coil
-3MA10 coil

You can try to use the two 3xv coils, if you don't have a 3ma lying around

I still doubt if its a fueling problem.
(To much compression wont cut out like that)