Originally Posted by user6ix
im good now on the LSN, I need to adjust the HSN and when I pull the trigger to 1/4 the engine don't have a power, like a sudden lost of power.
It's never a good thing to screw the needle into a seat.. This ultimately damages the needle or the seat/jet and makes the engine harder to the down the line.
Try this for a starting point:
1) Remove air filter and set your IDLE GAP to 1mm and while your there check the end points on the radio close it by pressing the break and when you full throttle it doesnt tug the carby off the engine.
2) Unwind the TOP needle, it doesnt really matter how much, as the LSN needle is what governs the idle and it's always good to know the HSN is allowing for fuel pressure
3) Remove your plug and clear the crank of residual fuel. If there's a lot of fuel continually misting from the engine then you know you are too rich on the LSN and it needs screwing in. Before you put your glow plug back in, check your glow plug is healthy and the glow starter is charged, if all good screw back in and attempt to start the engine.
You should at the first or second pull get it to fire, if it stops after that, then it's likely your LSN is rich, flooded and it's time to pull the glow plug and clear the crank and engine of residual fuel.
Turn the LSN inwards (clockwise 1/4 turn) and repeat this process until you can get the engine to idle without any throttle for 3-4 seconds. It will likely flame out as the engine is cold and it's best to fine tune the engine once it's nicely warmed up and this is done on track and when engine is under load.
4) By now you coan assume your idle mixture is relatively close to keeping it ruinning. Carefully give the engine a tiny bit of throttle ( 5% ) to warm it up, if it stalls you can turn in clockwise the HSN and try again. repeat this process until your engine is warmed up and you can put it down.
Once your idle mixture is set and you can throttle 50% without it stalling it's time to circulate under load and tune the HSN. For now ensure there's smoke
coming out of the pipe at all times. This doesnt mean there should be fuel spurting out, a good stream of combusted smoke is what we are after.
If you idle stays high once you are close to full throttle, then you may have to reduce the idle gap and chase it with the LSN
All the above is subject to:
Your engine being run in correctly
Using the correct fuel.
All engine components are secured well
Your engine having good compression
Your glow plug and starter in good health
No air leaks in the fuel line and tank
Exhaust gaskets are all in good check
And your bearings are sealed and in good condition.