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Post by geh3333 on Nov 3, 2014 20:07:59 GMT -5
Sorry to all that have messaged me in the past month , I've been unable to answer for personal reasons . But I am very happy with the results that I've heard .
First I want to say that while I was pushing others to try to use a bigger carb I was not able to explain why I was able to do so myself . I do believe that I should have done more research and tests on why I'm able to use the 32mm with a 125 main ,before I encouraged others to do so . I am no closer to being able to explain why this is possible and I do not want others to go forward in trying to fit a bigger carb unless they realize that it may not work for them , considering I have no clue at this point why I'm able to do so .
As for the work that was accomplished while I was gone , I'm glad to see that a buddy on here in which I encouraged to try his 30 mm carb did get a 28 mm with a 170 main to work , and he noticed very good gains . His scoot is now running at 73 mph on a straight run with his 61mm gy6200 . At this point I'm thinking he may have had a problem with his 30mm carb .
Another member has installed a 30mm with a 125 main and his scoot also has noticeable gains . He has pushed it up to 65 but was having problems with his rpms at top end not even reaching 7000 . These results were about a month ago and I'm really excited to see where they are at now " progress wise " .
Like I said , I don't want others to think they can just slap a 32mm carb on with a 125 and expect everything to go easy " like it did with mine " . I'd really like to know why I can run this setup on mine and others can't before I encourage others to do so . However if you have the extra time and money and want to give it a shot I'm all for it but please don't do so expecting it's gonna go easy . Thanks George
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Post by xyshannen on Nov 5, 2014 11:02:44 GMT -5
Geh, forr what it's worth, I'm also using a 30mm carb with 44 pilot and a 130 main. Even then I'm running a touch lean on the high side and have yet to try a 140 main. I'm hesitant to do so because a 140 is a heck of a jump and think I could fine tune it better with a 32mm carb and smaller jets.
Why you get away with it and why I believe I can get away with it has a lot to do with the other mods we've made. Little changes have a big impact on these little motors. During this time of year we get serious temp swings from day to day, heck from morning to noon can often see a 25 degree jump in the temp outside. For my motor to run perfect (i'm kinda OCD about this) requires an adjustment of the air fuel screw for every 20 or so degrees the temp changes.
I ported the crap out of my head, matched the porting to the spacer between the ram intake and the head, and then matched the manifold to the spacer. So there is nothing but smooth surface through my fuel delivery to the valves. I also worked the header mount and header pipe to smooth down anything that may inhibit flow. Add the extra velocity my tunnel ram creates and a fat cam and it makes perfect sense why I'm running lean with a 30mm carb.
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Post by scooter on Nov 5, 2014 17:01:36 GMT -5
...So there is nothing but smooth surface through my fuel delivery to the valves. I also worked the header mount and header pipe to smooth down anything that may inhibit flow. Add the extra velocity my tunnel ram creates and a fat cam and it makes perfect sense why I'm running lean with a 30mm carb. If you have or get a vacuum gauge, It would be great if you would publish your vacuum readings at the fuel pump, for reference, at various RPM, preferably at idle, 2,000, 3000, etc on up to 8,000 RPM, and also publish your fuel pressure at the pump outlet at those same RPMs, all with the bike on the center stand. I would really like to compare your readings to my stock carb. |
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Post by xyshannen on Nov 5, 2014 18:35:14 GMT -5
If i do, it will be a wile before I can. I can say with pretty good confidence that my cutting out problem and running lean are 2 different issues.
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Post by scooter on Nov 5, 2014 22:06:41 GMT -5
If i do, it will be a wile before I can. I can say with pretty good confidence that my cutting out problem and running lean are 2 different issues. Thank you. I'd really like to know how the bigger carb affects vacuum and fuel pressure, plus you have that long intake as well. |
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Post by geh3333 on Nov 6, 2014 11:19:56 GMT -5
Geh, forr what it's worth, I'm also using a 30mm carb with 44 pilot and a 130 main. Even then I'm running a touch lean on the high side and have yet to try a 140 main. I'm hesitant to do so because a 140 is a heck of a jump and think I could fine tune it better with a 32mm carb and smaller jets. Why you get away with it and why I believe I can get away with it has a lot to do with the other mods we've made. Little changes have a big impact on these little motors. During this time of year we get serious temp swings from day to day, heck from morning to noon can often see a 25 degree jump in the temp outside. For my motor to run perfect (i'm kinda OCD about this) requires an adjustment of the air fuel screw for every 20 or so degrees the temp changes. I ported the crap out of my head, matched the porting to the spacer between the ram intake and the head, and then matched the manifold to the spacer. So there is nothing but smooth surface through my fuel delivery to the valves. I also worked the header mount and header pipe to smooth down anything that may inhibit flow. Add the extra velocity my tunnel ram creates and a fat cam and it makes perfect sense why I'm running lean with a 30mm carb. Thanks for the reply , I was gone for about a month and before I left there were others that were having problems with tryin to get a bigger carb to work without running to rich . The members have a bigger bbk then ours and with just as much work done " that is with the top end and the exhaust " . Some couldn't even get a 115 main to work without being to rich . One member actually took his to a shop and they also were having the same issue . But when I returned I found out that after ordering a new carb " a 28mm mikuni racing carb" which is a very good carb , they were able to get it running and with a much bigger main then what was tried in the 30 mm carb . They concluded that there was something wrong with the 30mm carb although they couldn't pinpoint the problem . I was concerned about there being a possible issue with the carb itself " I mentioned it in a post before I was away " . I started to doubt what I was telling everyone about using a bigger carb , thinking here was just something going on with my setup that was allowing for the extra air and fuel " something not normal " but I see many others coming out with their results with bigger carbs and jets . For the past three yrs I've been somewhat preaching about how much others are missing out not using a bigger carb " because of the results I've had " . I was always met with much resistance when I would bring up the subject or when I would answer others questions about using a bigger carb , which would leave me frustrated knowing these modded engines are not reaching their full potential because I know they can take much more fuel and air then we once thought . Most mod their scoots so they can reach higher speeds and what I'm finding out is that we don't need to up the displacement as much as what was thought to be able to reach 70mph or near 70 mph . First thought would be " but how long will the engine last ?" . This still depends on how you ride and how you take care of the engine . The first season I rode somewhat easy and did not run the scoot to hard . For the past 2 seasons I've rode pretty hard but still kept up with the maintenance and right now I have over 15,000 miles on the engine. The crank was the only major part I did not change and I'm surprised how long it has held up " being the stock china crank " . I still stick by what I said earlier about wanting to find out why some cannot use a bigger carb " those with top end mods " . A picture is begining to appear and it seems that the main problem may be these cheap carbs that many are buying , some work just fine but some for whatever reason have internal issues that are causing them not to work correctly . On that note If I were to start over and need a new carb I would spend the extra cash and get a top brand carb like Kehein ,mikuni or oko . When it comes to the carb I would also order it from a reputable dealer or shop so u know your not purchasing a fake . Remember just because it cost more dosent mean it's not fake . Thanks for the replies , I'd like to hear from others who have either used a bigger carb with success or even if u tried a bigger carb and did not get it to work properly . Also please include any mods with your replies . Thanks George . |
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