So I have X30, fully rebuilt engine and tryton carb. Last sunday I was breaking in the engine with L jet settings of 1:10 and H 1:30. I started to push a little too early and it seized, this was that I thought was the root cause. So new honing, new piston next size in and to the track again yesterday. This time I opened the H more 1:45 to be sure I have enough cooling and lubrication. This time everything went well, I’m new to tryton and X30 so I’m a bit worried as it seems like I can open the H to over 2 TO and still it will not “4-stroke” on straigths and exhasut temp will anyway be in the 600C range. I get really bad drive in the range 8-11K rpm with the H 2TO but at higher rpms it pulls well to 14 (didnt try more yesterday because of my suspicion).
So my question to you that are used to x30 and tryton carb.
should I even be able to run the engine on straights with the H jet 2 TO?
in what rpm ranges shoud I see most effect from L vs. H screw
should the x30 engine “4-stroke” heavily on a long straight with H 2 TO?
seems like I could have some odd restrictoin on the fuel side as opening of the L and H jet only have effect under say 11K, over that it anyways runs fine (leans out) anyway. (lack fuel althoug 2TO H jet)
All gaskets are new, reeds, carb membranes etc. popoff is 0,85bars (12psi?).
Yes I was going up and down all the time. If not in a turn then I was coasting and sligthly braking it down and then on throttle again.
After the last 5min a continued to run it like the last 5min for 30min, and was testing the H settings and what’s when i became suspicious of the effect of H jet in this case as the EGT still came up to and over 600C with the H open 2 turns.
ok so it will run clean (without 4-stroking) but kill the plug more easily?
Anyone else having some thoughts regarding my fear of fule delivery problem at high RPM. Or was the problem just between steering wheel and seat the first time and that there is no problem with the fuel delivery at high RPM.
You can compensate to an extent, but there’s a point where the fuel flow coming into the jet chamber, (past the inlet needle which is controlled by the popoff pressure) becomes the choke point. Basically, there’s not enough fuel being supplied to the jet for the demand being applied to it.
It’s possible that the needle and/or seat (separated when pop off pressure is reached) are sticking, causing the higher reading. So start with a cleaning and let us know what you find.
That terminology is from the man himself E.C. Birt. A legend when it came to kart carburation, especially pump diaphragm carbs. If the terminology works for him and 1000’s of racers, it’s good enough for me.
@KartingIsLife what about good practises on how to lower if it really is too high. New spring? or can I get the spring rate change by pressing it togehter? Thats not usually how springs work but these are really small…