Other 61x-62T setup questions - running issues/backfiring

[95FX1]

first off lil background
my FX1 build - was 61x-61x - Now is 61x top 62T bottom...
used all 61x bottom parts just swaped over -electrics/flywheel - new starter
same MSD inhancer wired same way with MSD coil..all workin well from the old setup
1st issue;
so dropped rebuilt motor in - does not pull fuel to well...so it seems
few questions on stock setup - since the dual carb setup is new to me..Should there be 1 pulse line in each, the carb and the 62t bottom in the stock setup with 38s? my 38s have only 1 carb wth a pulse line. and the pulse line is on the 2nd carb in line with the fuel IN. The carb with the fuel IN does not have the pulse line so is it normal for the pulse to pull fuel thru both carbs? that does not seem effective to me.?

2nd issue;
i had it running for a few seconds and has 185psi in both. i was using some starter fluid to start it, then switched to just normal fuel mix down the carb. so all i can get it do do is backfire now??? still 185psi as i thought the starter fluid might of done something. Yes i know i should not of been using it...i had oil in the cylinder before i started messing with it. what would cause it to backfire only now?...i thought my builder might not of set my timing perfect of retarded it to far or something so i pulled everything out again. pulled the flywheel and the timing is set just about perfect - about 2mm counter clockwise...right where i had it before with the 61x bottom.

so now this is were i stand...i pulled motor to check timing...and timing is good.

why backfire and not running?
and do you 62t peeps have dual pulse?

HELP ??!!??​

 

[ntrsspray]

no only one pulse line...38s use only one fuel pump

sounds like the wiring is screwed up are you using 62t or 61x electronics...there is a wiring difference

 

[95FX1]

^^ i using the 61x wiring....i was told its swaps over...????!!!

im using new to me carbs with all new internals...but i didnt build them..so ill take a look inside to be sure all looks good..

low jet is 50 and high is 125
forget spring and needle/seat
was supposed to be setup stock with the jets 1 set high then stock.

thanx for the info

 

[aramis]

stock dual 38's only have one pulse line.

stock setup has fuel pump on rear carb (closest to pulse line fitting on case). That carb's fuel pump should have 3 connections: pulse, fuel IN (from tank) and fuel OUT (to front carb).

Front carb should have fuel IN (from rear carb) and then basically straight-through to a fuel OUT (return line to tank).

If yours aren't like that, fix that first...

 

[95FX1]

^^^ i deff have that OFF as Compared to that setup..
i had it backwards for sure...

i had it setup like....fuel IN was going to the front carb..then to the pulse/pump carb...

now i see why it didnt seem effective....
i thought that something seemed OFF??......the fuel IN needed to be at the fuel pump/pulse carb...now it makes sence..

Thanx for all the info...



anyone know what the Diff. tween the 61X electric's and the 62T?

 

[lerott]

Low jet need to be 70 and high jet 130, needle 1.5 and spring 115g (95g will work too)

 

[95FX1]

^^^ Thanx man...

ill pop em open and look again at what my set up is
should of done all this myself....

 

[cattledog]

it shard to see the 70 looks like 50 so it runs now, i bet its a 70 in there now

 

[95FX1]

Again....im realizing i should of set these carbs up my self....

 

[95FX1]

so cracked the carb open and NOT HAPPY at all...

and i have to take full responsibility for the fact they are not setup right.
my low jet was one of the super cheap ones that does not even say what it is on the side of it...but i have the bag they came in and that has a lable of 67.5 - one step down from stock - i have a set of 70s and 75s that i can use - i have some decent mods so ill run the 75s

and the high jet was a 125 - i have a set of 130 and 135s - so ill run the 135s and see how that goes..

needled was 1.5 and it was the dark colored spring...anyone know what spring that is? almost black

The intsructions i gave my builder was to go 1 step up from stock in my carbs please....and be sure they are clean and in good running condition.
BOTH Things where wrong...

 

[Matt_E]

In my experience, some stock jets were not imprinted with the size. They're not "super-cheap", just stock. At least those were the only ones I've seen lacking the numbers.

 

[95FX1]

^^ gotcha...

they look cheep....and when i removed them the tops crumpled easier then most jets do...
just sayin

 

[trxclint]

anyone know what the Diff. tween the 61X electric's and the 62T?

I'd like to know that as well.

 

[Matt_E]

The stator is different both in size and electrical properties.
The CDI is different. One connector on it is different from the 61X CDI (male instead of female or vice versa).
The 62T CDI will work with a 61X stator, but I am not sure that it works the other way around. (It may, I'm just not sure)

 

[jetski jerry]

The stator is different both in size and electrical properties.
The CDI is different. One connector on it is different from the 61X CDI (male instead of female or vice versa).
The 62T CDI will work with a 61X stator, but I am not sure that it works the other way around. (It may, I'm just not sure)

yes matt is right 62t stater &flywheel is bigger. cdi will work with ether one need to make jumper wire with male on each end so you can hook the green wire up. the only diff is the green wire plugs are oppaset.

 

[95FX1]

i took everything from my 61x bottom and put it in an empty set of 62t cases....


It was running already...just had some carb issues and had gas lines hooked wrong

so flywheel-stator-Ebox all just swapped into the 62t cases...if all my stuff matches up since it was 61x...and all parts fit in the cases, so why would it not run.??

 

[Matt_E]

You need to figure out if it's a carburetion problem or an electric problem. Are you getting spark?

 

[95FX1]

spark 100% before i pulled it...
but now i cleaned carbs 100% and will do fuel lines properly...

see how it goes when i drop it all back in this weekend...

thanx for advice
and ill update this to see if she runs again when all put back together

 

[JetManiac]

so cracked the carb open and NOT HAPPY at all...

and i have to take full responsibility for the fact they are not setup right.
my low jet was one of the super cheap ones that does not even say what it is on the side of it...but i have the bag they came in and that has a lable of 67.5 - one step down from stock - i have a set of 70s and 75s that i can use - i have some decent mods so ill run the 75s

and the high jet was a 125 - i have a set of 130 and 135s - so ill run the 135s and see how that goes..

needled was 1.5 and it was the dark colored spring...anyone know what spring that is? almost black

The intsructions i gave my builder was to go 1 step up from stock in my carbs please....and be sure they are clean and in good running condition.
BOTH Things where wrong...

Live and learn right? Hope nothing was damaged.

You should run 75pilot/95 or 115g springs/at least 135 high depending on your setup. Don't forget to check rubber tips of the needles (stock 1.5N&S). They can 'ring up' and dribble fuel or not popoff cleanly.

I am constantly amazed at how many freeriders are rebuilding motors or having motors built ,but not rebuilding (or at least checking thoroughly) their electrics and carbs.

Rebuilding is too expensive and time consuming to repeat twice because of crappy fuel delivery or weak spark, etc.

 

[95FX1]

Live and learn right? Hope nothing was damaged.

So far nothing seems damaged....SO FAR -
and yes ill run the 75low and 135high jets on this set up...Bottom line my little pump cant deal with much more then what its setup now..

^^^ love your parts Jetmaniac ^^^