justin_smallwood Posted October 5, 2017 Report Share Posted October 5, 2017 Hello enthusiasts. Where would be the best place on the intake to tap and still for the vacuum line for a pump. The reason I ask is because my intake was already drilled on The bottom of the intake so I used that to put the barb fitting for the hose. On the big end my bike high revs and seem not to be getting fuel and running lean, and I'm wondering by having the vacuum on the bottom, that maybe when the reeds open up, is blocking my air flow to the line. Thanks for any knowledge Sent from my LG-D722 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Keno Posted October 5, 2017 Report Share Posted October 5, 2017 You want the pulse feed to be on the top or side of the intake with the pump mounted somewhere above the feed. And no low spots in the pulse tube. Ideally distance between the pump and the pulse port need to be as short a possible (within reason). With the pulse feed on the bottom, or the pump below the feed, you are allowing fuel to accumulate in the tubing and/or pump. This drastically decreases the pulse signal to the pump. Quote Link to comment Share on other sites More sharing options...
n2otoofast4u Posted October 5, 2017 Report Share Posted October 5, 2017 What's the rest of the setup?Sent from my SM-G900V using Tapatalk Quote Link to comment Share on other sites More sharing options...
justin_smallwood Posted October 5, 2017 Author Report Share Posted October 5, 2017 You want the pulse feed to be on the top or side of the intake with the pump mounted somewhere above the feed. And no low spots in the pulse tube. Ideally distance between the pump and the pulse port need to be as short a possible (within reason). With the pulse feed on the bottom, or the pump below the feed, you are allowing fuel to accumulate in the tubing and/or pump. This drastically decreases the pulse signal to the pump. Man you are spot on....I did fail to mention that when I rev I see the vacuum line fillng up with fuel...which may be doing all the way down the track. Thank you so much for the clarification. Just for personal knowledge. Why would the vacuum be so different on the bottom opposed to the side and top??Sent from my LG-D722 using Tapatalk Quote Link to comment Share on other sites More sharing options...
specialblend07 Posted October 5, 2017 Report Share Posted October 5, 2017 Just now, justin_smallwood said: Man you are spot on....I did fail to mention that when I rev I see the vacuum line fillng up with fuel...which may be doing all the way down the track. Thank you so much for the clarification. Just for personal knowledge. Why would the vacuum be so different on the bottom opposed to the side and top?? Sent from my LG-D722 using Tapatalk Gravity maybe? I dunno Quote Link to comment Share on other sites More sharing options...
justin_smallwood Posted October 5, 2017 Author Report Share Posted October 5, 2017 What's the rest of the setup?Sent from my SM-G900V using Tapatalk421 cub , 20 domes cut by noss, .049 squish, don't know compression...drag port..on alky, 40mm pwkSent from my LG-D722 using Tapatalk Quote Link to comment Share on other sites More sharing options...
justin_smallwood Posted October 5, 2017 Author Report Share Posted October 5, 2017 Gravity maybe? I dunnoTrue..just wasn't for sure if the fuel splashed around in the intake or just generally sat at the bottom..Sent from my LG-D722 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Keno Posted October 5, 2017 Report Share Posted October 5, 2017 Gravity Fuel and oil have a lot more mass than air and if they are occluding the tube, the fuel/oil will absorb most of the pulse energy meant for the pump diaphragm Edit: I noticed you keep saying vaccum. The pump is actuated by the positive and negative pulses in the crankcase. Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted October 6, 2017 Report Share Posted October 6, 2017 What pump are you using? Just curious Quote Link to comment Share on other sites More sharing options...
justin_smallwood Posted October 6, 2017 Author Report Share Posted October 6, 2017 Have no idea...just came with the carbs..I'll see if I can post a picSent from my LG-D722 using Tapatalk Quote Link to comment Share on other sites More sharing options...
justin_smallwood Posted October 6, 2017 Author Report Share Posted October 6, 2017 Have no idea...just came with the carbs..I'll see if I can post a picSent from my LG-D722 using TapatalkBest pic I have[/qe]Sent from my LG-D722 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Keno Posted October 6, 2017 Report Share Posted October 6, 2017 That's a Mikuni DF-62 Quote Link to comment Share on other sites More sharing options...
justin_smallwood Posted October 6, 2017 Author Report Share Posted October 6, 2017 That's a Mikuni DF-62U sure know a lot about pumps. And once I move the vacuum to the side, the location of the pump now, will that be fine?Sent from my LG-D722 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Keno Posted October 6, 2017 Report Share Posted October 6, 2017 Common pump in jetskis is all. Personally, I would build a bracket and not use zipties. Quote Link to comment Share on other sites More sharing options...
registered user Posted October 6, 2017 Report Share Posted October 6, 2017 i would keep a eye on the f/s section and ebay for gravity carbs then throw that current setup in the bushes. who ever had the bike previously must of got them carbs for free. other wise theres no explanation why a reasonably compotent person would do such a thing Quote Link to comment Share on other sites More sharing options...
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