stroking Posted January 31, 2011 Report Share Posted January 31, 2011 (edited) I have a bike that i got thats got a fuel pump on it,it was ran on race fuel,but i switched it too alky and drilled the dump to 132/ main jet and now its spraying alky out the pipes..it wont even rev up becuase of all the alky pouring out the pipes..if i remove the pump will that solve the problem.....all other alky bikes i did,didnt have a pump oh and this is a BIG motor so im not sure if removing the pump would be safe. is there anything different that they do in the carbs when running a pump? seems like the pump is pumping to much fuel too fast....also have alky flowing through the pump line thats tapped into the cylinder Edited January 31, 2011 by stroking Quote Link to comment Share on other sites More sharing options...
n2otoofast4u Posted January 31, 2011 Report Share Posted January 31, 2011 First off.... That motor isnt very big at all!!! What size are the needle and seats? 132 seems WAY too big, and those PJs you have are the second ever invented.. Which way is the alky coming from that is going through the pulse line? Are you 100% sure you have it hooked up correct.. Its possible that there is so much fuel flowing through the reeds that it could back feed throught he pulse.. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted January 31, 2011 Report Share Posted January 31, 2011 Simple...yes. Put fuel pump needle and seats in the carbs, they are smaller than gravity fed. Unless you've done that, they're going to pour fuel, especially with the DF62 pump you're using there...it pushes 65L per hour of fuel. And run a longer pulse line as well. Quote Link to comment Share on other sites More sharing options...
sheefreak Posted January 31, 2011 Report Share Posted January 31, 2011 I don't know that a .132 dump tube is ever gonna work. You could drop the needle all the way and I think you are still gonna spray raw fuel out the pipes. If the pump was pumping too much, it would be coming out the carb overflows. Spraying raw fuel happens when you are too rich on the needle or mid range ckt. It won't even be pulling off the PJ's as you are sitting rapping on it. I would drop the needle all the way and see if this helps, if not, you may need to look for a new set of carbs. Quote Link to comment Share on other sites More sharing options...
stroking Posted January 31, 2011 Author Report Share Posted January 31, 2011 First off.... That motor isnt very big at all!!! What size are the needle and seats? 132 seems WAY too big, and those PJs you have are the second ever invented.. Which way is the alky coming from that is going through the pulse line? Are you 100% sure you have it hooked up correct.. Its possible that there is so much fuel flowing through the reeds that it could back feed throught he pulse.. its almost 600cc so i think it is BIG I got the bike with all this already hooked up Quote Link to comment Share on other sites More sharing options...
stroking Posted January 31, 2011 Author Report Share Posted January 31, 2011 i got another set of carbs i will try without the pump connected Quote Link to comment Share on other sites More sharing options...
BANSHEE HP Posted January 31, 2011 Report Share Posted January 31, 2011 mikuni has a removable nozzles so your not stuck with the .132, get a new set of nozzles. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted January 31, 2011 Report Share Posted January 31, 2011 Yep...also called emulsion tubes. I am not VERY familiar with Mikunis, so I couldn't tell you what to drill the tube and main out to, but .132 is WAY too big IMO. Make sure the needle and seat is correct for a fuel pump as well. Quote Link to comment Share on other sites More sharing options...
BANSHEE HP Posted January 31, 2011 Report Share Posted January 31, 2011 whats the size of this motor? bore and stroke. you said 600cc. i would say .122-.125 or so. Quote Link to comment Share on other sites More sharing options...
J-Madd Posted January 31, 2011 Report Share Posted January 31, 2011 How far are racing? Gravity feed will be fine for a 14 mil Cheetah. Quote Link to comment Share on other sites More sharing options...
n2otoofast4u Posted January 31, 2011 Report Share Posted January 31, 2011 Im with j-madd.... Unless you are running pavement distances, Id take the pump off, get another set of emulsion tubes and drill them to 122, change out those PJs to a set of clippards, find out what needle/seat setup you have and make them properly sized for gravity, and run without the pump.. No sence in adding stuff on that dont need to be there.. If its only 600cc then theres no reason to pump it unless you are running 1/4 mile or some crazy distance. Even then I think I would drill the passages, use bigger bowls, and a few simple things to avoid the pump.. Not saying it wont work with the pump if its setup right, just saying thats just one more thing to fail and cost you some cash.. Quote Link to comment Share on other sites More sharing options...
bada450r Posted February 1, 2011 Report Share Posted February 1, 2011 whats the size of this motor? bore and stroke. you said 600cc. i would say .122-.125 or so. more like 118..........reg stock needle center clip[needle that comes with carbs when bought new].....55 pilot and i would leave the pump on........that jetting would be for sea level........have fun.......also replace that main hose the one going from the cylinder to the pump those hoses tent to collapse.......one more thing it gets expensive trying to save money..imo Quote Link to comment Share on other sites More sharing options...
bada450r Posted February 1, 2011 Report Share Posted February 1, 2011 (edited) Yep...also called emulsion tubes. I am not VERY familiar with Mikunis, so I couldn't tell you what to drill the tube and main out to, but .132 is WAY too big IMO. Make sure the needle and seat is correct for a fuel pump as well. all the makunis i have run have not being set up for a pump.......i just have run them with a return line............no needle or seat changes are really need it.......that of course is jut my experience. also that pingel might not flow enough alky to feed the motor Edited February 1, 2011 by bada450r Quote Link to comment Share on other sites More sharing options...
stroking Posted February 1, 2011 Author Report Share Posted February 1, 2011 How far are racing? Gravity feed will be fine for a 14 mil Cheetah. its bigger than that and we run 1/8mile pavement i switched the carbs to kehin 38mm without the pump and needed a seat belt after that to stay on the bike im going to try the pump again when i put the motor back together,tore it down to check things out,and found a few problems...like a .022 squish for one theres going to be a mad HULK on the loose soon!!! Quote Link to comment Share on other sites More sharing options...
J-Madd Posted February 1, 2011 Report Share Posted February 1, 2011 Well, with 8th mile you might need a pump. THose Mikuni billet bowls are relatively small. I have an identical set on my 16 Mil Cheetah(610cc). I tried to run a pump last year and never got it to work out with any pumper carbs except some PWKs. I'm going with the Mikunis gravity fed this year. What size motor is that? 14 Mil Cheetah is a 593 cc, 16 is 610 cc....... Quote Link to comment Share on other sites More sharing options...
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