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Post by tsimi on Jan 2, 2016 22:35:37 GMT -5
First thing today,...gasoline stand. Once the tank was full I went for a test drive with a 95 MJ. And she likes it a lot. Highest rpms thus far (9400). The pilot jet (40) is too large according to Brents tuning manual. I get highest rpms when the mixture screw is all the way in. I will try 38 next but that might need again adjusting the MJ. Here an image of the spark plug after a few WOT runs with the 95 MJ.  Man I love the power and response of that 19mm PHBG carb. Just awesome and it is not even tuned right yet. And the hoses stayed in place this time. |
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Post by spaz12 on Jan 2, 2016 23:50:03 GMT -5
Plug looks good from my house.  |
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Post by tsimi on Jan 3, 2016 4:09:20 GMT -5
Washed and waxed the Scooter. Looks very shiny and clean now.
Also swapped the Pilot from 40 to 38, unfortunately not much difference when tuning the mixture screw. Same again all the way in (all the way in = towards lean) gives me the highest and best condition thus far. So if 38 is too large what would be best? Maybe a 35? or even lower? Need to check treatland.tv for pilot jet sizes and sets.
I think I'm gonna stay with the 95 MJ for now I get good results spark plug wise and performance wise. Why risking a lean condition right?
My question now is, if I leave the mixture screw all the way in would that give me also a lean condition at mid and WOT range? Or is the mixture screw only for 0 - 1/4 throttle area?
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Post by Lucass2T on Jan 3, 2016 5:00:00 GMT -5
Washed and waxed the Scooter. Looks very shiny and clean now. Also swapped the Pilot from 40 to 38, unfortunately not much difference when tuning the mixture screw. Same again all the way in (all the way in = towards lean) gives me the highest and best condition thus far. So if 38 is too large what would be best? Maybe a 35? or even lower? Need to check treatland.tv for pilot jet sizes and sets. I think I'm gonna stay with the 95 MJ for now I get good results spark plug wise and performance wise. Why risking a lean condition right? My question now is, if I leave the mixture screw all the way in would that give me also a lean condition at mid and WOT range? Or is the mixture screw only for 0 - 1/4 throttle area? Mixture screw is only for idle and the very short moment when you go on the throttle...so lets say untill 1/8 throttle. You choose the pilot jet of which you think comes closest to ideal size...and with the mixture screw you do the finetuning. And finetuning starts from 360 + 180 degrees screwed out from the richest position. You know you got it right when with a warm engine you have a calm and evenly idle. And when you give a slight burst of gas it reacts directly BUT ALSO returns back to idle instantly. |
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Jog-Mania
Jan 3, 2016 5:13:04 GMT -5
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Post by tsimi on Jan 3, 2016 5:13:04 GMT -5
Thanks Lucass.
So if I get the best idle condition thus far with the mixture screw all the way in then I can leave it like that until I can get a smaller pilot.
I have good and steady idle even if the mixture screw is in its default position. (2 turns out) What I try to achieve is, I want to remove the slight sputter I have at low throttle around 1/8 - 1/4.
So again, I don't need to worry that the mixture screw leans out my mid range and WOT condition right?
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Post by oldgeek on Jan 3, 2016 5:32:48 GMT -5
....... What I try to achieve is, I want to remove the slight sputter I have at low throttle around 1/8 - 1/4. So again, I don't need to worry that the mixture screw leans out my mid range and WOT condition right? Most likely your slide then. In my experience with the dells, the mixture fuel screw does have a very slight affect through the whole range. Forgive me if I missed it somewhere, but what components do you have in your dell? Slide, jet needle, and such?  |
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Jog-Mania
Jan 3, 2016 5:54:38 GMT -5
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Post by tsimi on Jan 3, 2016 5:54:38 GMT -5
....... What I try to achieve is, I want to remove the slight sputter I have at low throttle around 1/8 - 1/4. So again, I don't need to worry that the mixture screw leans out my mid range and WOT condition right? Most likely your slide then. In my experience with the dells, the mixture fuel screw does have a very slight affect through the whole range. Forgive me if I missed it somewhere, but what components do you have in your dell? Slide, jet needle, and such? It's hard to explain where the sputter is. From 0 to 1/4 it is not that crisp and it sputters a tiny bit. Other then that all is good. I am sure I can sort that out if I could adjust the mixture screw correctly, which is not possible at the moment. According to Brents tuning manual you have t find the spot that gives you the highest rpm, the sweet spot. Too much or too few and you miss it. That sweet spot for me is at the moment with the screw all the way in. I don't know more then that because I can't go further then that. My carb is equiped with stock slide, no idea what number. MJ 95, PJ 38, idle jet 60, atomizer 262AN, W9 needle (position 2nd from top). |
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Post by oldgeek on Jan 3, 2016 6:07:51 GMT -5
If it is a genuine dell the slide should be stamped. If it is a clone it may not be marked. The clones I picked up had #50 slides, which is lean. You need a 40 or a 30 or something in between. You can easily modify a 30 to make it a larger #
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Jog-Mania
Jan 3, 2016 6:16:15 GMT -5
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Post by tsimi on Jan 3, 2016 6:16:15 GMT -5
It is a genuine Dello. I will take a look tomorrow what slide it is.
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Jog-Mania
Jan 3, 2016 6:53:48 GMT -5
via mobile
Post by tsimi on Jan 3, 2016 6:53:48 GMT -5
Other thought, should I go down from a 95 to 92 MJ and see if it fixes it?
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Post by 90GTVert on Jan 3, 2016 8:11:41 GMT -5
The bottom end may need more work, but I always find the main jet that does the best before I worry about the other stuff.
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Jog-Mania
Jan 3, 2016 8:14:31 GMT -5
via mobile
Post by tsimi on Jan 3, 2016 8:14:31 GMT -5
So you would suggest to go down on the jet once and see from there? Which would be a 92 since I don't have 93 and 94.
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Post by 90GTVert on Jan 3, 2016 8:25:39 GMT -5
That's what I'd try since you just got over the sputtering and overly rich condition, but there's a chance it's too lean so it's up to you. I generally prefer to see the sweet spot in jetting by tuning till performance decreases and then going back. It's safer to say it works now and the plug looks good so just leave it.
If you leave the main jet, how is the mid throttle? If it's sputtering you could try leaning the needle one notch and see what happens since it doesn't sound like you have more jets and throttle valves around. If it never sputters in the midrange I wouldn't go any leaner on the needle though.
My genuine dells usually come with a 40 slide.
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Jog-Mania
Jan 3, 2016 8:34:51 GMT -5
via mobile
Post by tsimi on Jan 3, 2016 8:34:51 GMT -5
As you could see the spark plug color is not bad with the 95 MJ. Mid range is all good, no sputter or surging.
Response is also all good on any range. The only thing I have is that tiny sputter between 0 and 1/4 and I am not able to adjust the mixture screw since the PJ is too large.
I could put back the 40 pilot and go once down to a 92 MJ but as you said it might run lean(er) and 2 strokes run strong on lean conditions until it is too late.
So either 38/40 PJ and 92 MJ or something below 38 PJ and 95 MJ. I could order a pilot jet set from treatland which comes with a 30, 35 and 37 PJ. I would love to try the 35 PJ once with the 95 MJ.
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Post by Lucass2T on Jan 3, 2016 10:04:41 GMT -5
What you're having right now is exactly the same as what i had with my first metrakit engine before it blew up. Not that it blew up bcause of that but to let you know its not my current engine.
I thought the slide could solve the problem but the engine blew up (needle bearing failed) before i could try.
My Dell PHVB has a .40 slide too. I wanted to try a .50 slide with a bigger cutaway to lean the mixture out from idle to 1/4 throttle.
That was my theory to solve the problem...
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