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Post by jerseyboy on Feb 6, 2015 9:57:12 GMT -5
30 didn't work, 28 did, bigger is not always better. Have we finally cleared that up?  I found that out going up one size on the pilot jet last week,,the GY6 sat there blowing out black smoke at an idle,,like somebody had the choke pulled shut.....horrible..so I still run my stock 38 I believe it is.... |
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Post by alleyoop on Feb 6, 2015 12:49:09 GMT -5
30 didn't work, 28 did, bigger is not always better. Have we finally cleared that up? +10 on that one Jerry And for those that asked about the 24J carbs the pilots are #35 and the Mains are anywhere from 103-107s. Alleyoop |
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Post by rcq92130 on Feb 6, 2015 12:59:41 GMT -5
No, Jerry, not cleared up (despite experts insisting we are stupid and should just do as we are told, w/o explanation).
WHY is it a properly jetted larger carb is worse. The only explanation so far is that the vacuum in the venturi is lower (correct) ~~ and the result of this is less fuel sucked up into the airstream (and thus a lean mixture). That, however, simply means the larger carb has not been properly jetted. A larger main jet will produce a correct a/f mixture (accounting for the lower vacuum).
So then - why is a PROPERLY JETTED LARGER CARB not at least as good as a properly jetted smaller carb? It's a passive device, not a turbo. It simply tries to supply what the engine demands. A larger carb may not be BETTER (if the smaller carb fully satisfies what the engine demands) .... but why is a properly jetted larger carb EVER going to be worse?
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Post by jerseyboy on Feb 6, 2015 13:31:55 GMT -5
The big question is why are you guys with big carbs running lower weight rollers and sliders,,thats the one that has me scatchin my head  My scooter is strong on bottom end through midrange below 7K RPM with 12-13g..maybe the lack of vacuum and whatever else is happening is causing the bottom to mid to be effected? I have no idea but just saying,,I need to get one and test myself... |
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Post by alleyoop on Feb 6, 2015 14:10:58 GMT -5
The big question is why are you guys with big carbs running lower weight rollers and sliders,,thats the one that has me scatchin my head My scooter is strong on bottom end through midrange below 7K RPM with 12-13g..maybe the lack of vacuum and whatever else is happening is causing the bottom to mid to be effected? I have no idea but just saying,,I need to get one and test myself... That is a fact Jersey, my 62bbk even with a 60mm stroker I am running with 12 gram Dr. Pulley Sliders and can get 7+ rpms. I have it set up so I do not need high rpms to get top end speed plus I do not like high rpms anywhy and high rpms is not good for any motor. Not to put fuel in the fire but I am tired of these two mentioning me in their BS posts to get me to respond, I mean it is so obvious they are itching for a pissing match..LOL Well here is my response, What you two should be be asking yourselves is WHY OH WHY out of THOUSANDS only TWO of us need 9 gram weights to get descent rpms. Now get your two heads working and pming each other and what not and figure out what is common between you two. It is NOT the variators they are different so that theory goes out the door, but I believe you two will be able to figure it out. Most of us on here already know the answer and it wasn't just me but a few real motor heads also mentioned what the problem is was and will be.  KNOWS. Alleyoop |
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Post by JerryScript on Feb 6, 2015 15:22:14 GMT -5
No, Jerry, not cleared up (despite experts insisting we are stupid and should just do as we are told, w/o explanation). WHY is it a properly jetted larger carb is worse. The only explanation so far is that the vacuum in the venturi is lower (correct) :: and the result of this is less fuel sucked up into the airstream (and thus a lean mixture). That, however, simply means the larger carb has not been properly jetted. A larger main jet will produce a correct a/f mixture (accounting for the lower vacuum). So then - why is a PROPERLY JETTED LARGER CARB not at least as good as a properly jetted smaller carb? It's a passive device, not a turbo. It simply tries to supply what the engine demands. A larger carb may not be BETTER (if the smaller carb fully satisfies what the engine demands) .... but why is a properly jetted larger carb EVER going to be worse? Unfortunately, as this article explains, I cannot give you hard numbers that will apply to every situation in order to explain it. Hopefully this article puts it into terms everyone can understand. (note- this is written about cars, but applies to all carb based engines) www.hotrod.com/how-to/engine/selecting-right-carb/GY6 are not designed to be run at high RPMs for a long time, proper CVT tuning should keep your RPMs in the 3-5k range most of the time, nor do they have high enough compression to require extra large carbs. That being said, if you have modified your GY6 and/or the final drive gears, you may have use for a larger carb, but not necessarily! |
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Post by jerseyboy on Feb 6, 2015 16:31:03 GMT -5
What we should do is race them also..but I dont see that happening,,plus none of us weigh the same,,Im 170lbs.
I should have some numbers this summer as i plan on messing around with a bigger carb and different jetting and weights,,Im getting a cheap gopro cam clone to snap to my helmet and I have a GPS,,will do the tests on the same road,same condition.
Will be like 0-30,,0-45,,and zero to 60mph tests,,we will see what happens..the bigger carb might exel in the higher RPM's while the smaller one lower to mid...who knows???
Geh,,what are your RPM,s at WOT from 20mph to high gear?
Mine are about 6.5K or there about,,pulling hard,,then after the CVT is in high gear it starts climbing R's from there.
I dont like running mine higher than 6K but thats me,I cruise between 5-6K,,people have ran them 7-7.5K for many miles from what I read...
Stay tuned...well its gonna be a while with this weather.
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Post by rcq92130 on Feb 6, 2015 17:00:09 GMT -5
Thanks, JS. Interesting.
Normally, when a less knowledgeable person comes to an expert and asks "why", and the expert denigrates or puts the junior person down and tries to make him feel stupid, it's because the expert does not know the answer and is trying to not let on he does not know. Here that seems very, very unlikely. So it's not clear why people who genuinely want to learn and understand are made to feel dumb.
So it's appreciated, JS, that you found the Demon Carb link ... and interesting. The article seems to say a larger carb is preferable UNLESS it is causing low end drivability problems. Preferable because it gives the engine more WOT breathability, but a problem if the engine then bogs down at low speeds/throttle.
My own situation is pretty confusing with all this. My low end performance is SUPER - from traffic lights it's rare the cars keep up with me - only if THEY are really gunning it. I'd gladly trade some of this for more max speed! Also, the engine exhibits none of the normal symptoms of bad mixture: no popping at all, ever; no bogging down, or very, very little; smooth from low speed to top speed. But my max RPMs are low ---- never above 7,400; usually down to about 7,000 (with a 115mm DP variator & 9gm sliders). I do NOT see the kind of top speed GEH gets (my scoot has a stock clutch & gearing, and tiny 10" wheels). Maybe the very upright windshield is to blame for that. But without any popping I presume the engine, if anything, is not running lean.
It would be interesting to figure all this out. And, either dyno or 1-on-1 comparisons of the same scooter with different carbs would be VERY interesting!
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Post by geh3333 on Feb 6, 2015 17:42:44 GMT -5
Again he does not listen to the facts . there was a problem with the 30mm carb " probably in the cast since it was a cheap carb" even the shop said this . a 115 or 110 was still showing too rich with that carb . but a way bigger jet worked in the 28mm ? Listen a little please.
Alley u don't listen what so ever . u take information an try to twist it in our favor . its false information u are putting out by doing this .
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Post by geh3333 on Feb 6, 2015 17:48:11 GMT -5
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Post by geh3333 on Feb 6, 2015 17:53:23 GMT -5
There goes why u think I have to use lighter weights . u were part of it Ur only showing ur true colors to everyone. This thread shows the different cast . I'll post another were I explain the roller weight difference. |
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Post by rcq92130 on Feb 6, 2015 18:02:26 GMT -5
I'm suspecting my variator as well, GEH. Old news: when I was looking for a bigger variator I asked people here. Alley eventually replied Koso was the best, but by the time he did I had already ordered the Dr Pully ($  ) so I just stuck with it. Then had problems with it SERIOUSLY chewing up sliders (those were 11gr), which i fortunately caught before it all flew apart. Now with a different inner face (not Dr P) it seems to not be as rough on the 9gr sliders, so I'll just let is stay for a while. When i DO replace the thing i'll go Koso. but how to avoid the crappy casting problem you ran into. Do you think the Koso from tvnacman is OK |
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Post by geh3333 on Feb 6, 2015 18:18:17 GMT -5
I'm suspecting my variator as well, GEH. Old news: when I was looking for a bigger variator I asked people here. Alley eventually replied Koso was the best, but by the time he did I had already ordered the Dr Pully ($ ) so I just stuck with it. Then had problems with it SERIOUSLY chewing up sliders (those were 11gr), which i fortunately caught before it all flew apart. Now with a different inner face (not Dr P) it seems to not be as rough on the 9gr sliders, so I'll just let is stay for a while. When i DO replace the thing i'll go Koso. but how to avoid the crappy casting problem you ran into. Do you think the Koso from tvnacman is OK I would say yes . if and when I get a new one it will be ordered through him . anyway I was looking through threads and say in the infamous "73 mph video " I mentioned the 9.5 gram rollers not 9 gram as I thought " I know there at other threads in which I explained the reason for the lighter weights in which alley was part of . I once got my belt to drop in the variator by using the old back plate from my first koso on the new cast. But because it WS eaten up from busted v slide guides I had to go back to the other back plate. Also I remember weighing both koso variators and the new on was a good bit heavier which may also have an impact on reaching a higher rpm without dropping weights. |
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Post by alleyoop on Feb 6, 2015 18:33:44 GMT -5
Like I said you two get together and figure out the million dollar question, I told you guys why ages ago we just keep on going round and round. The one I feel sorry for is RC, you are the one that talked him into it when I said differently. Now he also is questioning why he also needs 9gram weights on a 150cc motor to gain some rpms when only you two out of thousands need to.
Please don't tell him its his Variator if anything 99 percent of all performance variator will give you more rpms and bottom end but lack top end capability. Now Don't forget I heard your motor on that downhill run and it was not putting out like it should and I told you so, even when you were at the stop light.
And don't start with your colors are showing crapola and saying I make you feel stupid. After trying to tell you guys nicely and then getting on my case because I do not agree, Maybe a little put down will open up your eyes, but from what I have seen and heard I would not bet on it.
You talk about showing your colors ,
Now why on earth would YOU TWO out of thin air create TWO THREADS not just one and mention me and wanting me to respond.
THAT MY FRIEND SHOWS YOUR COLORS. I don't know about others but I may have been born late BUT NOT YESTERDAY.
I have responded and you can take it or leave it and just live with what you have.
Ride Safe
Alleyoop
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Post by geh3333 on Feb 6, 2015 18:39:59 GMT -5
You keep putting out miss information ! At least your coming around on a bigger carb being better .
You sound ridiculous when u say the reason for the lighter weights is the bigger carb . when I've already found the variator is to blame. All of my three stock variators ran 10.5 gram weights and up , my first koso also . and with the bigger carb. Its the different koso cast I made the thread about . hey rc do u have a stock variator ? If so can u put it in and see what weights it takes ?
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..BAD TO THE BONE..
) so I just stuck with it. Then had problems with it SERIOUSLY chewing up sliders (those were 11gr), which i fortunately caught before it all flew apart. Now with a different inner face (not Dr P) it seems to not be as rough on the 9gr sliders, so I'll just let is stay for a while.