hot start extreme difficulty

[noobi]

my 07 ec125, has just had a new piston and rings. and now its become very difficult to start hot. i have to put the choke on and open the throttle to WOT and kick it really hard to get any sign of life out of it.
it wasnt this hard before the new piston.
everything was fine when i did the rebuild, no bore scratches or wiggle in bottom end.
one of my bike mates suggested it could be the jetting, i dont know

its a 40 pilot jet, a 175 main jet with a N1EG on the 2nd position, air screw 3 turns out

any help would be appreciated

 

[widebear]

Air screw adjustment is to lean , try 1 turn out.

 

[noobi]

Air screw adjustment is to lean , try 1 turn out.

ok, thanks

the bike shop commented on how it was happier with the air screw 5 turns out and suggested a biger pilot. does that make sense with what your saying?

 

[iancp5]

ok, thanks

the bike shop commented on how it was happier with the air screw 5 turns out and suggested a biger pilot. does that make sense with what your saying?

5 turns out! It must be nearly falling out

If you need 5 turns out I think it suggests you need a smaller pilot. Turning it out leans the mixture. It's easy to adjust so if I was you I'd put it back to standard ride the bike and see how it behaves. You'll probably need to adjust the throttle stop to get an idle if it's setup 5 turns out.

 

[noobi]

5 turns out! It must be nearly falling out

If you need 5 turns out I think it suggests you need a smaller pilot. Turning it out leans the mixture. It's easy to adjust so if I was you I'd put it back to standard ride the bike and see how it behaves. You'll probably need to adjust the throttle stop to get an idle if it's setup 5 turns out.

dunno really. ill play around with the air screw tomorrow, school holidays are great for playing with bikes, and see if i can sort it out. but the report i got from the shop definately says bigger pilot

 

[GMP]

Five turns out is crazy. There is something very wrong to make it run better like that. How does it run otherwise, is it OK once your off the idle/pilot circuit? Did the carb come apart for some reason?

 

[rpduc]

If the shop is saying bigger pilot AND screwing the air screw out they've got some wires crossed...

That could have been a brain fart on someone's part.

Put in the bigger pilot they suggested and start at 1 turn out and see what you get.

By 2nd position I assume you mean second from the bottom? Because second from the top would also lean it out.

 

[noobi]

If the shop is saying bigger pilot AND screwing the air screw out they've got some wires crossed...

That could have been a brain fart on someone's part.

Put in the bigger pilot they suggested and start at 1 turn out and see what you get.

By 2nd position I assume you mean second from the bottom? Because second from the top would also lean it out.

no, 2nd clip from the top!?!?
the bike runs very well on and off the pilot circuitry, its just hard to start, and it wasnt like that before the new piston, it doesnt exactly rip my arms off, but its a 125 not a 450. there are no flat spots to speak off and revs up cleanly. but i dont know the difference between a well jetted bike and a poorly jetted bike. it runs and its smooth

 

[widebear]

Noobi.rpduc's advice is correct. The air screw's adjustment range is only 0 to approx 2.5 turns out. Half to one and a half turns out being the sweet spot. Anything either side of those parrameters will require a pilot jet change.

 

[noobi]

Noobi.rpduc's advice is correct. The air screw's adjustment range is only 0 to approx 2.5 turns out. Half to one and a half turns out being the sweet spot. Anything either side of those parrameters will require a pilot jet change.

ok, ill invest in some pilot jets. 42?

 

[noobi]

ok, problem solved. set the air screw to 1 turn out, problem was much better. played around with it for an hour or so and found 1 and 3/4 of a turn out to be the best setting. bike was very responsive from no nearly no revs in second, i had a few bails just getting used to the new responsiveness.
thanks for the help everyone, i wouldnt have associated this problem with jetting, but glad its sorted

 

[wence]

ok, problem solved. set the air screw to 1 turn out, problem was much better. played around with it for an hour or so and found 1 and 3/4 of a turn out to be the best setting. bike was very responsive from no nearly no revs in second, i had a few bails just getting used to the new responsiveness.
thanks for the help everyone, i wouldnt have associated this problem with jetting, but glad its sorted

Ok mate,
You don't know the difference between running rich and lean?
Put a 195 main in and go for a run down the street. The bike should run ok on pilot then chug and splutter and not rev out...... this is how it feels when a bike runs rich.
Now if you dare , drop the main to a 165 and do the same run and see how it feels...
If it pings or feels very responsive work up from there.
Ideally you will get a feeling for it as I did .
So long as you interpret the bike and don't rev the ring out of it you will be ok.
It is a pain in the arse changing main jets but a quick and easy way to get a ballpark on what feels right.
I have a 300 and was running a 180 on the 4th clip from bottom.
Changed from 32:1 to 50:1 fuel mixture( which I recommend), Dropped the clip position to middle and then puit a 200 main in.
Ran crappy.
Put a 170 in , ran awesome but thought to be safe I would put the 180 in.
Still runs great although not as snappy, but for me it is better to be a little richer.
Try it and you will see.
Good luck.
Mark

 

[noobi]

Ok mate,
You don't know the difference between running rich and lean?
Put a 195 main in and go for a run down the street. The bike should run ok on pilot then chug and splutter and not rev out...... this is how it feels when a bike runs rich.
Now if you dare , drop the main to a 165 and do the same run and see how it feels...
If it pings or feels very responsive work up from there.
Ideally you will get a feeling for it as I did .
So long as you interpret the bike and don't rev the ring out of it you will be ok.
It is a pain in the arse changing main jets but a quick and easy way to get a ballpark on what feels right.
I have a 300 and was running a 180 on the 4th clip from bottom.
Changed from 32:1 to 50:1 fuel mixture( which I recommend), Dropped the clip position to middle and then puit a 200 main in.
Ran crappy.
Put a 170 in , ran awesome but thought to be safe I would put the 180 in.
Still runs great although not as snappy, but for me it is better to be a little richer.
Try it and you will see.
Good luck.
Mark

if its lean, will it pink? too much air?
the top end is rich i think. lots of spooge, or have i crossed wires associating spooge with richness? theres too much fuel for the pipe temp to burn the excess, meaning spooge?
i havent changed any jets. still have a 40 pilot. just the air screw was tweaked.

plus, i dont have jets to africa to test. sorry, so cant do those tests.

 

[wence]

if its lean, will it pink? too much air?
the top end is rich i think. lots of spooge, or have i crossed wires associating spooge with richness? theres too much fuel for the pipe temp to burn the excess, meaning spooge?
i havent changed any jets. still have a 40 pilot. just the air screw was tweaked.

plus, i dont have jets to africa to test. sorry, so cant do those tests.

Pity mate cos that would tell you.
Spooge and richness is not linked as far as I know.
If you can borrow the jets It would help you.
What fuel are you running at what mixture?
Cheers Mark

 

[noobi]

Pity mate cos that would tell you.
Spooge and richness is not linked as far as I know.
If you can borrow the jets It would help you.
What fuel are you running at what mixture?
Cheers Mark

40:1 castrol TTS. with 96 or 98 where available
iv read stuff about spooge, it could be the oil mix, but it only happens when im on the main jet lots, not during a tight forest ride.
ill try and source some jets from some motox mates, and do the test.

thanks, dale

 

[wence]

40:1 castrol TTS. with 96 or 98 where available
iv read stuff about spooge, it could be the oil mix, but it only happens when im on the main jet lots, not during a tight forest ride.
ill try and source some jets from some motox mates, and do the test.

thanks, dale

I was running TTS at 32:1 and had no spooge on the 300 using the same type fuel.
I still would suggest borrowing the main jets to try.... thats what I did.
They were only about ten buck to buy I reckon but a mate had a whole stack which I used to check.
All the best Mark.